WO2024194453A1

WO2024194453A1 - A battery assembly housing

Info

Publication number: WO2024194453A1
Application number: PCT/EP2024/057716
Authority: WO
Inventors: Florian Hartmann; Gabriele RIVA; Rodyn GILHARRY; Chan In JUNG
Original assignee: Northvolt Ab
Priority date: 2023-03-23
Filing date: 2024-03-22
Publication date: 2024-09-26
Also published as: SE2350330A1

Abstract

A battery assembly housing configured to receive a plurality of battery cells at respective predetermined locations wherein each battery cell includes a vent, wherein the battery assembly housing includes a cover plate having a slot that forms an opening in the cover plate and wherein the slot is configured and arranged to span a plurality of the vents of the battery cells, and wherein the slot includes a foam to one or more of absorb energy, receive material and receive gases ejected from one or more of the vents of the plurality of battery cells in the event of thermal runaway.

Description

A BATTERY ASSEMBLY HOUSING

Field

The present disclosure relates to a battery assembly housing and, in particular, to a battery assembly housing including a slot to receive a foam and associated methods. The disclosure also relates to a battery assembly. The disclosure also relates to a battery assembly housing including a bracket that is affixed to a cooling plate by an adhesive.

Background

The safety of electrochemical battery cells is important. It is known for battery cells to experience thermal runaway, in which there is uncontrolled selfheating. Thermal runaway may be caused by damage to the battery cell or a defect. Pressure may build within a casing of the battery cell during such a thermal runaway event, which may lead to rupture and the violent ejection of material. A plurality of battery cells may be mounted together and thus the ejection of material from one of the battery cells presents a hazard to the other battery cells.

Provision of an effective housing for the battery cells is also important. Ensuring that a housing is robust while also being straightforward to manufacture or assemble is a challenge. The housing may include one or more thermal management features. Thus, the housing may need to provide effective cooling to the battery cells and/or other components that may be part of, or coupled to, the housing.

Summary

According to a first aspect of the present disclosure there is provided a battery assembly housing configured to receive a plurality of battery cells at respective predetermined locations wherein each battery cell includes a vent, wherein the battery assembly housing includes a cover plate having a slot that forms an opening in the cover plate and wherein the slot is configured and arranged to span a plurality of the vents of the battery cells, and wherein the slot includes a foam to one or more of absorb energy, receive material and receive gases ejected from one or more of the vents of the plurality of battery cells in the event of thermal runaway.

In one or more embodiments, the cover plate includes a plurality of ribs that extend between a first longitudinal side of the slot and a second longitudinal side of the slot to divide the slot into a plurality of sub-sections, each subsection comprising an opening in the cover plate for one of a respective vent or a plurality of adjacent vents, wherein the ribs extend, at least in part, through the foam.

In one or more embodiments, at least one of the plurality of ribs is configured to be spaced from the plurality of battery cells to provide a gap between said at least one of the plurality of ribs and the plurality of battery cells, wherein the gap is at least partially filled by the foam.

In one or more embodiments, the extent of the foam is defined by a size of the slot in the cover plate.

In one or more embodiments, a thickness of the foam is less than a thickness of the cover plate.

In one or more embodiments, the battery assembly housing is configured to receive a plurality of prismatic battery cells.

In one or more embodiments, the cover plate includes a peripheral edge that defines the slot and that is configured to seal against the plurality of battery cells when loaded in the battery assembly housing and wherein one of: the peripheral edge that defines the slot includes an adhesive configured to adhere and seal against the plurality of battery cells when mounted in the battery assembly housing; and the peripheral edge that defines the slot includes a seal configured to abut and seal against the plurality of battery cells when mounted in the battery assembly housing. In one or more embodiments, the battery assembly housing comprises: a cooling plate configured to form a base of the battery assembly housing and configured to receive the plurality of battery cells side by side in at least one row, a first end plate coupled to the cooling plate at a first edge and positioned to lie adjacent a first end the at least one row of battery cells, a second end plate coupled to the cooling plate at an opposed, second edge and positioned to lie adjacent an opposed, second end of the at least one row of battery cells, a first side wall coupled to the cooling plate and configured to lie adjacent a plurality of sides of the at least one row of battery cells; a second side wall coupled to the cooling plate, opposed the first side wall; and wherein the cover plate is received on the first and second end plate and the first and second side walls.

In one or more embodiments, at least one of the first end plate and the second end plate are coupled to the cooling plate at least in part by a bracket that is affixed to the cooling plate by a thermal adhesive.

In one or more embodiments, said at least one of the first end plate and the second end plate is configured to receive an electronic control unit for controlling the plurality of battery cells that are to be mounted in the battery assembly housing and wherein the bracket is of a thermally conductive material to thermally couple, and thereby provide cooling for, the electronic control unit when in use.

According to a second aspect of the present disclosure there is provided a battery assembly comprising the battery assembly housing of the first aspect including the plurality of battery cells loaded therein.

According to a third aspect of the present disclosure there is provided a method of forming a battery assembly comprising: receiving a battery assembly housing; loading the battery assembly housing with a plurality of battery cells at respective predetermined locations wherein each battery cell includes a vent, placing a cover plate over the plurality of battery cells, wherein the cover plate includes a slot that forms an opening in the cover plate and wherein the slot is configured and arranged to span a plurality of the vents of the battery cells; and applying a foam into the slot, the foam configured to one or more of absorb energy, receive material and receive gases ejected from one or more of the vents of the plurality of battery cells in the event of thermal runaway.

In one or more embodiments, the foam comprises an expanding foam material configured to expand to at least partially fill the slot once applied therein.

In one or more embodiments, the cover plate includes a peripheral edge that defines the slot and that is configured to seal against the plurality of battery cells loaded in the battery assembly housing, wherein the method includes one or both of applying adhesive to the peripheral edge and applying adhesive to the plurality of battery cells at locations where the peripheral edge seals against the plurality of battery cells.

In one or more embodiments, the cover plate includes a plurality of ribs that extend between a first longitudinal side of the slot and a second longitudinal side of the slot to divide the slot into a plurality of sub-sections, each subsection comprising an opening in the cover plate for one of a respective vent or a plurality of adjacent vents; and wherein at least one of the plurality of ribs is spaced from the peripheral edge to provide a gap between said at least one of the plurality of ribs and the plurality of battery cells; and wherein the foam comprises an expanding foam; wherein the method comprises: applying the expanding foam into the slot such that it flows through said gap so that the foam is applied to a plurality of said sub-sections. According to a fourth aspect of the present disclosure there is provided a battery assembly housing configured to receive a plurality of battery cells, comprising: a cooling plate configured to form a base of the battery assembly housing and configured to receive the plurality of battery cells, a plurality of walls extending from and coupled to a first side of the cooling plate; wherein at least one of the plurality of walls is coupled to the cooling plate at least in part by a bracket that is affixed to the cooling plate by an adhesive.

In one or more embodiments, the adhesive comprises a thermal adhesive.

In one or more embodiments, said at least one of the plurality of walls comprises an outer wall and an inner wall connected by a plurality of webs, wherein the bracket is configured to structurally couple said at least one of the plurality of walls to the cooling plate to resist a swelling force generated by swelling of the plurality of battery cells when loaded in the battery assembly housing.

In one or more embodiments, said at least one of the plurality of walls is configured to receive an electronic control unit for controlling the plurality of battery cells that are to be mounted in the battery assembly housing and wherein the bracket is of a thermally conductive material to thermally couple the electronic control unit to the cooling plate via the thermal adhesive to thereby provide cooling for said electronic control unit when in use.

In one or more embodiments, said at least one of the plurality of walls comprises an outer wall and an inner wall connected by a plurality of webs, wherein the bracket is coupled to the outer wall and is received between the plurality of webs and wherein the electronic control unit is also coupled to the outer wall.

In one or more embodiments, said at least one of the plurality of walls includes a slot between the webs to slidably receive the bracket therein to thereby locate the at least one of the plurality of walls in a predetermined location relative to the cooling plate.

In one or more embodiments, the cooling plate is configured to receive the plurality of battery cells side by side in a row and wherein the plurality of walls comprise: a first end plate coupled to the cooling plate at a first edge and positioned adjacent a first end the row of battery cells, a second end plate coupled to the cooling plate at an opposed, second edge and positioned adjacent an opposed, second end of the row of battery cells, a first side wall coupled to the cooling plate and positioned adjacent a plurality of sides of the row of battery cells; a second side wall coupled to the cooling plate, opposed the first side wall; and wherein the bracket is configured to couple at least one of the first end plate and the second end plate to the cooling plate.

In one or more embodiments, the cooling plate is configured to receive the plurality of battery cells arranged in a first row of battery cells arranged side by side and a second row of battery cells arranged side by side and wherein the plurality of walls comprise: a first first-row end plate coupled to the cooling plate at a first edge and positioned adjacent a first end of the first row of battery cells, a second first-row end plate coupled to the cooling plate at an opposed, second edge and positioned adjacent an opposed, second end of the first row of battery cells, a first second-row end plate coupled to the cooling plate at the first edge and positioned adjacent a first end of the second row of battery cells, a second second-row end plate coupled to the cooling plate at the opposed, second edge and positioned adjacent an opposed, second end of the second row of battery cells, a first side wall coupled to the cooling plate and positioned adjacent a plurality of sides of the first row of battery cells; a second side wall coupled to the cooling plate, opposed the first side wall and positioned adjacent a plurality of sides of the second row of battery cells; and wherein the bracket is configured to couple at least one of the first and second first-row end plates and the first and second second-row end plates to the cooling plate.

In one or more embodiments, a plurality of brackets are provided to couple a respective one of each the first and the second first-row end plates and the first and the second second-row end plates to the cooling plate.

In one or more embodiments, the first first-row end plate and the first second- row end plate are coupled together by a first half-lap joint; and the second first-row end plate and the second second-row end plate are coupled together by a second half-lap joint.

In one or more embodiments, the battery assembly housing includes a separator wall arranged between the first row of battery cells and the second row of battery cells, wherein the separator wall includes a first flange at a first end configured to be received within the first half-lap joint and a second flange at an opposed second end configured to be received within the second half-lap joint.

In one or more embodiments, the first half-lap joint is configured to receive a fixing that extends through the first first-row end plate, the first flange and the first second-row end plate to secure them together; and/or the second half-lap joint is configured to receive a fixing that extends through the second first-row end plate, the second flange and the second second-row end plate to secure them together.

In one or more embodiments, the first side wall is coupled by fixings to the first first-row end plate, the second first-row end plate and the cooling plate; and/or the second side wall is coupled by fixings to the first second-row end plate, the second second-row end plate and the cooling plate. In one or more embodiments, the cooling plate includes a plurality of channels therein to receive a flow of coolant between a first port and a second port.

In one or more embodiments, a cover plate is received on the plurality of walls opposite the cooling plate to define an enclosed volume for receiving said plurality of battery cells.

In one or more embodiments, the plurality of battery cells are to be received at respective predetermined locations in the battery assembly housing, wherein each battery cell includes a vent, and wherein the cover plate includes a slot that forms an opening in the cover plate and wherein the slot is configured and arranged to span a plurality of the vents of the battery cells, and wherein the slot includes a foam to one or more of absorb energy, receive material and receive gases ejected from one or more of the vents of the plurality of battery cells in the event of thermal runaway.

According to a fifth aspect of the disclosure, we provide a battery assembly comprising the battery assembly housing of the fourth aspect including the plurality of battery cells loaded therein.

While the disclosure is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail.

The figures and Detailed Description that follow also exemplify various example embodiments. Various example embodiments may be more completely understood in consideration of the following Detailed Description in connection with the accompanying Drawings.

Brief Description of the Drawings

One or more embodiments will now be described by way of example only with reference to the accompanying drawings in which: Figure 1 shows an example battery assembly comprising a battery assembly housing loaded with a plurality of battery cells;

Figure 2 shows the battery assembly housing of figure 1 with a cover plate separated therefrom;

Figure 3 shows a more detailed view of the example cover plate showing a slot;

Figure 4 shows a cross-section through the slot;

Figure 5 shows a flow-chart illustrating an example method;

Figure 6 shows a cooling plate of the battery assembly housing of figure 1;

Figure 7 shows an end-view of the example battery assembly showing a electronic control unit;

Figure 8 shows a first view of an example wall comprising an end plate;

Figure 9 shows a second view of the end-plate; and

Figure 10 shows a detailed view of an example half-lap joint configured to couple two adjacent end plates.

Detailed Description

Example figure 1 shows a battery assembly 100 comprising a battery assembly housing 101 loaded with a plurality of battery cells 102 (partially visible in figure 1). The battery cells in the present examples comprise prismatic battery cells. However, the disclosure is not limited to an implementation in which the battery assembly 100 is configured to receive prismatic battery cells. The battery assembly 100 when loaded with the battery cells 102 comprises a battery module or a battery pack.

Example figure 2 shows the battery assembly housing 101 without the plurality of battery cells loaded therein. Further, a cover plate 103 of the battery assembly housing 101 is shown spaced from the remainder of the battery assembly housing 101.

It will be appreciated that defects in battery cells, such as caused by damage or by other reasons, may lead to an increase in heat and pressure within the battery cell. As will be known by those in the art, the battery cells 102 may experience "thermal runaway" in which chemical reactions within the battery cell create temperatures and pressures beyond their design limits which can lead to ejection of material including gases and/or particulate matter.

When a plurality of battery cells 101 are arranged together, such as in the battery assembly housing 101, it is important, in one or more embodiments, that the ejection of material from one battery cell does not cause damage to a different battery cell in the battery assembly housing 101. The ejected material may affect a nearby cell for one or more reasons such as by virtue of it being electrically conductive, its temperature, the speed of ejection or the direction of ejection. Thus, it may be important to make provision so that a battery cell that ejects material and/or experiences thermal runaway will not cause damage that may cause further battery cells to experience thermal runaway.

Example figure 3 shows a more detailed view of the cover plate 103 shown in figures 1 and 2. Example figure 4 shows a cross-section through the cover plate 103.

An embodiment of the battery assembly housing 101 will now be described with references to figures 1-4.

The battery assembly housing 101 is configured to receive a plurality of battery cells at respective predetermined locations within a walled tray 200. The construction of the walled tray 200 will be described later. In the present example, the plurality of battery cells are received in two rows in a first-row space 201 and a second-row space 202. However, it will be appreciated that in other examples, the battery assembly housing 101 may be arranged in only a single row or grouping of battery cells or in more than two rows. Thus, the prismatic battery cells may be substantially rectangular cuboid in shape and may be arranged together side-by-side in the first-row space 201 and the second-row space 202 with the same respective side facing upwards to receive the cover plate 103.

The battery assembly housing 101 includes the cover plate 103 to close an open side of the walled tray 200 and thereby enclose the plurality of battery cells in the battery assembly housing 101. The cover plate 103 has a slot 104 that forms an opening in the cover plate 103. In fact, in the present example there are two slots comprising the slot 104 and a second slot 105. The slot 104 is aligned with the battery cells that are to be located in the first row space 201 and the second slot 105 is aligned with the battery cells that are to be located in the second row space 202.

Each prismatic battery cell of the plurality of battery cells 102 includes a vent 106 for venting of gases or providing an exit in the event of thermal runaway. The vents 106 are formed in the respective cell casings or outer structure of each prismatic battery cell. The vents 106 are typically located at a predetermined position on the prismatic battery cells 102. Accordingly, if the plurality of battery cells are received at respective predetermined locations, then the vents 106 will be aligned at respective predetermined locations.

The slots 104, 105 are configured and arranged to span a plurality of the vents 106 of the battery cells 102. The slots 104, 105 thus provide an opening to allow material ejected from the vents 106 of the plurality of battery cells to exit the battery assembly housing 101 when the plurality of battery cells are mounted in the battery assembly housing 101 and experience thermal runaway.

Thus, in the present example, the battery cells 102 are arranged in one or more rows and thus their respective vents are also arranged in one or more rows and each slot may span the vents of the battery cells in a particular row. In other examples, a plurality of distinct slots may serve a single row of battery cells. Accordingly, the vents 106 of a single row of battery cells may be aligned with two or more distinct slots in the cover plate 103.

With reference to example figure 3, the cover plate 103 may include a peripheral edge 107 that defines the edge of the opening defined by the slot 104, 105 and that is configured to seal against the plurality of battery cells 102.

Thus, when the plurality of battery cells 102 are loaded in the battery assembly housing 101, a surface 108 of each battery cell, comprising the surface in which the vent 106 is formed, may face the open side of the walled tray 200 and may receive the cover plate 103. Each of the surfaces 108 may be aligned side-by- side to form a substantially contiguous surface, although there may be gaps between adjacent battery cells 102.

Further, with reference to figure 4, the slot 104 and the second slot 105 includes foam 400 to absorb energy, receive ejected gases, and/or receive the material or "ejecta" that exits through said vents 106 in the event of thermal runaway. The foam may be an open cell foam. The foam may be an expanding foam that has expanded and set or cured in the slot 104, 105. The foam may be configured to extend over the entire footprint of the slots 104, 105. In some examples, the foam may fill the slots 104, 105.

Thus, the slots 104, 105 provide a guide in which the foam is received. The provision of the peripheral edge 107, that seals against the surfaces 108 of the plurality of battery cells 106, may also assist in retaining the foam in the slots 104, 105. In other examples, the viscosity of the foam may be chosen such that when applied to the slot(s) 104, 105, the slot(s) may substantially guide and limit the extent of the foam 400 even if gaps are present between the cover plate 103 and the surface 108.

As mentioned, in one or more examples, the foam 400 may be the product of an expanding foam. Thus, the cover plate 103 may be placed over the battery cells in the battery assembly housing 101. In some examples, the peripheral edge 107 seals against the surfaces 108. An expanding foam material may be added or poured into the slots 104, 105 which may be retained in the slot and, in some examples, additionally by the sealing peripheral edge 107. The expanding foam may thus flow over each of the vents while being retained in the slots 104, 105 before or while expanding to form the foam 400. In some examples, the expanding foam may flow between the plurality of battery cells 102, such as between the battery cells in the first row space 201 and the second row space 202.

The slots 104, 105 may thereby provide a retaining channel in which the foam is received. The foam 400 is non-combustible. In particular, the foam may be non-combustible to a degree such that on receipt of material ejected from a battery cell experiencing thermal runaway it does not combust.

By including foam adjacent the vents 106, particulate ejecta may be caught whilst allowing gaseous ejecta and heat to diffuse through the foam and out of the slot 104, 105. Further, the foam may also suppress any flames associated with the ejection of material . The foam 400 may absorb the energy of a thermal runaway event, even if a localised portion of the foam is broken away by the force of the thermal runaway event. In addition, an open cell foam may be advantageous in that flame and/or ejecta will propagate into its open cell structure rather than being deflected back towards the venting battery cell.

In one or more examples, the foam may be configured to partially melt during venting from a battery cell 102 through the respective vent 106, but this melt has been found to be localised and the foam may assist in energy absorption due to the change in phase and thereby reduce the potential impact on other battery cells 101.

In one or more examples, the foam 400 adjacent each of the vents 106 may be configured to absorb the energy from a thermal runaway event and may be configured to break away from the remainder of the foam in the slot 104, 105. The foam that remains may also act to protect adjacent battery cells 102 to the one experiencing thermal runaway by preventing the hot ejecta from reaching the vent 106 or surface 108. The thickness of the foam and/or the frangibility of the foam may therefore be controlled such that any foam that breaks away during a thermal runaway event for a particular cell is limited in extent to the foam that extends over the vent 106 of that particular cell. In one or more examples, the slot 104, 105 may be shaped, such as with undercuts, to assist with retention of the foam in the slot around the cell experiencing thermal runaway. Thus, while a portion of the foam directly adjacent the vent 106 of the runaway battery cell may break away, the remainder of the foam remains in the slot 104, 105.

In one or more examples, the foam comprises a thermal runaway protection foam. Such foams may be of expanding type. In other examples, the foam comprises one of: metal based foam, a polymer based foam, a composite based foam, a polyurethane based foam, a silicone based foam or an epoxy based foam.

In one or more examples, the cover plate 103 may include a plurality of ribs 110 that extend between a first longitudinal side 111 of the slot 104, 105 and a second longitudinal side 112 of the slot to divide the slot into a plurality of sub-sections 116. Each sub-section 116 may thereby comprise an opening in the cover plate 103 for a respective vent 106 or group of vents, wherein the ribs 110 extend, at least in part, through the foam 400.

The ribs 110 may be configured, by virtue of extending at least in part through the foam 400, to disrupt its structural integrity along the length of the slot 104, 105. Thus, in the event of thermal runaway for a particular one of the plurality of cells 102, the ribs 110 may promote separation of a portion of the foam over vent 106 of that particular cell 102 thereby ensuring that foam is retained over the vents 106 of adjacent battery cells 102 to protect them.

It will also be appreciated that in several embodiments, it may be desirable for the foam to absorb the energy of the thermal runaway event without breaking away, but the presence of the ribs 400 or control of the thickness or frangibility may act to promote retention of the foam over battery cells not experiencing thermal runaway should the thermal runaway event nevertheless cause part of the foam to break away with the force of the ejected material / energy.

In the present example, the plurality of ribs 110 are spaced upward from the peripheral edge to provide a gap 117 between each rib 110 and the outwardly facing surface 108 of the plurality of battery cells. It will be appreciated that the foam may at least partially fill the gaps 117.

The provision of the gaps 117 may be advantageous if an expanding foam or flowable foam is used. Thus, the foam may be added to the slots 104, 105 and the gaps 117 may permit the foam to flow along the slots 104, 105 into a plurality of the sub-sections 116. For an expandable foam, the expandable foam may be permitted to flow between the surface 108 and the ribs 110 through the gaps 117 and then expand to at least partially fill each of the subsections 116.

In the present examples, the extent of the foam is defined by a size of the slots

104, 105 in the cover plate 103. The slots 104, 105 thereby define a space to receive the foam and manage the extent to which it may spread when first applied to the slots 104, 105 by virtue of its shape and the peripheral edge 107.

With reference to figure 4, the thickness 401 of the foam 400 is less than a thickness 402 of the cover plate 103. In other examples, the thickness 401 of the foam 400 may be substantially equal to the thickness 402 of the cover plate 103. In other examples, the thickness 401 of the foam 400 may be greater than the thickness 402 of the cover plate 103 and the foam may be applied such as to be retained substantially within the footprint of the slot 104,

105. Thus, the foam 400 may be applied such that it does not spread from the slot 104, 105 and over the cover plate 103 adjacent the slots 104, 105.

In the present example, in order for the peripheral edge 107 to effectively seal against the surface 108 of the plurality of battery cells 102 an adhesive is applied thereto. The adhesive may be applied as a tape or a bead and the cover plate 103 may be applied over the battery cells 102 which may then adhere the peripheral edge 107 to the surfaces 108 of the plurality of cells. The adhesive may be applied continuously around the peripheral edge 107 or discontinuously.

In other examples, the peripheral edge 107 may carry a seal, such as a compressible silicone sealing bead configured to abut and seal against the surface 108 of each of the battery cells. In other examples, a gasket may be placed over the battery cells 102 that aligns with the peripheral edge 107 to aid sealing when the cover plate 103 is positioned.

Example Figure 4 also shows a cell connector moulding 403 configured to be mounted between the plurality of battery cells 102 and the cover plate 103. The cell connector moulding 403 may provide a frame for the electrical connections to the plurality of battery cells 102 and guide one or more conductive wires to terminals or controllers mounted elsewhere. Thus, in the present example, the cell connector moulding 403 is configured to present an aperture at least over the predetermined locations of the vents 106. The cover plate 103 is received over the cell connector moulding 403. In other examples, the cells 102 may be electrically connected in a different way, such as without a cell connector moulding 403.

We also disclose a method of forming a battery assembly with reference to figure 5. The method may comprise the steps of: receiving 501 a battery assembly housing; loading 502 the battery assembly housing with a plurality of battery cells at respective predetermined locations wherein each battery cell includes a vent, placing 503 a cover plate over the plurality of battery cells, wherein the cover plate includes a slot that forms an opening in the cover plate and wherein the slot is configured and arranged to span a plurality of the vents of the battery cells to allow material ejected from the vents of the plurality of battery cells to exit the battery assembly housing; and applying 504 a foam material into the slot, the foam material configured to one or more of absorb energy, receive gases and receive said material that exits through said vents.

As mentioned above, the foam material may comprise an expanding foam configured to expand to at least partially fill the slot 104, 105 once applied therein. The method may include, prior to step 503 or as part of step 503, one or both of applying adhesive to the peripheral edge and applying adhesive to the plurality of battery cells at locations where the peripheral edge seals against the plurality of battery cells 102.

In embodiments wherein the cover plate 103 includes the ribs 110, the step 504 may comprise applying the foam material into the slot such that it flows through said gap such that the foam material is applied to a plurality of said sub-sections 116.

We will now describe the structure of the walled tray 200. In one or more advantageous aspects, with reference to figure 2, and irrespective of the design of the cover plate 103 described above, the battery assembly housing 101 may comprise a cooling plate 203 and a plurality of walls 204-209 extending from and coupled to a common side of the cooling plate 103. Thus, the cooling plate 103 is configured to form a base or face of the battery assembly housing 101. The base or face may comprise the component upon which the plurality of battery cells 102 are received when loaded into the battery assembly housing 101.

In general, the cooling plate 203 is configured to receive the plurality of battery cells side by side in a row. The plurality of walls 204-209 may comprise a first end plate, a second end plate, a first side wall and a second side wall. In some examples, the end plates and side walls may themselves be of multiple parts or may be single rigid structures.

In the present examples, the battery assembly housing 101 is configured to receive the plurality of battery cells arranged side-by-side in a first row (in the first-row space 201) and side-by-side in an adjacent second row (in the second- row space 202). In this example, the plurality of walls comprise a first first- row end plate 204 coupled to the cooling plate 203 at a first edge 211 and positioned to lie adjacent a first end of the first row of battery cells. A second first-row end plate 205 is coupled to the cooling plate 203 at an opposed, second edge 212 and positioned to lie adjacent an opposed, second end of the first row of battery cells. A first second-row end plate 206 is coupled to the cooling plate 203 at the first edge 211 and positioned to lie adjacent a first end of the second row of battery cells. A second second-row end plate 207 is coupled to the cooling plate 203 at the opposed, second edge 212 and positioned to lie adjacent an opposed, second end of the second row of battery cells. Thus, in one or more examples, the walls (i.e. the end plates 204-207) at the ends of the rows of battery cells are divided into sections, wherein a section is provided for each row of battery cells.

Further, the plurality of walls comprise a first side wall 208 coupled to the cooling plate 203 and configured to lie adjacent a plurality of sides of the first row of battery cells. Further, the plurality of walls comprise a second side wall 209 coupled to the cooling plate 203, opposed the first side wall 208 and configured to lie adjacent a plurality of sides of the second row of battery cells.

The cooling plate 203 is shown separate in Figure 6. Thus, with reference to figure 2 and figure 6, four of the plurality of walls 204-209 are coupled to the cooling plate 203 at least in part by a respective bracket 601-604 that is affixed to the cooling plate 203 by an adhesive. The adhesive may be a thermal adhesive in one or more examples. In the present example, four brackets 601- 604 are shown for coupling to four of the plurality of walls 204, 205, 206, 207 but in other examples a different number of the walls 204-209 may be coupled by the adhesively secured brackets.

The brackets may provide structural support to the walls. The structural support may be configured to act against swelling of the plurality of battery cells. The brackets may be mounted at a mid-point along the length of the wall, as shown. In the event of swelling of the battery cells, the end plates 204- 207, located at the ends of the row of battery cells, may be subjected to a combined force from plurality of the swelling cells. Thus, the brackets are advantageous in providing support to the end plates, in particular.

In the present example the brackets are configured to couple the first and second first-row end plates 205, 206 and the first and second second-row end plates 207, 208 to the cooling plate 203. The first side wall 208 and second side wall 209 may be configured to be secured to the cooling plate 203 by different means, such as by bolts extending through fixings 213, 613.

This example embodiment may be advantageous, particularly when the adhesive comprises thermal adhesive, because the brackets 601-604, by virtue of their attachment to the cooling plate 203 by the thermal adhesive, can provide cooling to the walls / end plates 205-208. Thus, the thermally conductive bracket and thermally conductive adhesive and the thermally conductive wall thereby thermally couples the walls to the cooling plate. This may provide improved cooling for the sides and/or ends of the prismatic cells 102 mounted within the battery assembly housing 101 as well as to any electronic components that may also be mounted on said walls 204-207.

This example embodiment is advantageous because the end-plates are coupled together at one side by the first side wall 208 and an opposed side by the second side wall 209 while the bracket(s) may be configured to support a midpoint therebetween. In examples with multiple rows of battery cells, this example embodiment is advantageous because the end-plates are coupled together at one side by one of the first side wall 208 and the second side wall 209 and at the other side by a separator wall 215 while the bracket(s) may be configured to support a mid-point therebetween.

Figure 6 also shows a first port 605 and a second port 606 for the circulation of a coolant through channels in the cooling plate 203 (present on the underside in this example).

Figure 7 shows an example wherein one of the plurality of walls 206 has an electronic control unit 700 mounted thereto for controlling the plurality of battery cells that are to be mounted in the battery assembly housing 101. In other examples, the electronic control unit 700 may serve other control purposes. Thus, the thermally conductive bracket 603, which may be of metal, thermally couples the electronic control unit 700 to the cooling plate 203 via the thermal adhesive to thereby provide cooling for the electronic control unit 700 when in use. In such an example, the wall 206 or walls 204-207 may be of a thermally conductive material, such as metal.

Example figures 8 and 9 show an example of the structure of one of the first and second first-row end plates 205, 206 and the first and second second-row end plates 207, 208. In particular, the first second-row end-plate 206 is shown.

The end plates, or side walls 208, 209 in other examples, comprises an outer wall 801 and an inner wall 802. The walls are so named because when the end plate 206 is part of the battery assembly housing 101, the inner wall is configured to face inwardly and thereby contact the battery cells therein, and the outer wall 801 is configured to face outwardly from the battery assembly housing 101.

The outer wall 801 and the inner wall 802 are spaced apart and connected by a plurality of webs 803. It will be appreciated that the end-plates may be extruded. In the present example, the plurality of webs 803 are configured to define a slot 804 to slidably receive the bracket 603 therein to thereby locate the end-plate relative to the cooling plate 203.

Thus, the bracket 603 (or other bracket) is configured to be received between the outer wall and the inner wall between the webs 803. In particular, in the present example, the brackets is received against an inner surface of the outer wall 801, in the slot 804, between the plurality of webs 803. Fixings 805, 806 may extend through the outer wall 801 and the bracket to couple them together.

As will be appreciated from the description of Figure 7 above, the electronic control unit 700 or other electronics that may benefit from cooling may be mounted to the outer wall 801 on an opposite side to the bracket 603.

The first first-row end plate 204 and the first second-row end plate 206 abut one another when they are positioned along the first edge 211. The first first- row end plate 204 and the first second-row end plate 206 may be coupled together by a first half-lap joint.

With reference to figures 8 and 9, a side of the first second-row end plate 206 may be of a reduced thickness 807 and may be configured such that it may overlap with a complementary side of reduced thickness of the adjacent end end-plate, that is the first first-row end plate 204. Thus, when the reduced thickness parts overlap, their combined thickness is substantially equal to that of the thickness of the end-plate. A fixing may be provided through the halflap joint to secure the end-plates 204, 206 together.

A similar coupling arrangement may be provided for the second first-row end plate 205 and the second second-row end plate 207, which may be coupled together by a second half-lap joint. It will be appreciated that in other examples, different joints may be used as well as different joints for different pairs of end-plates.

With reference to Figure 2, one or more of the rows of battery cells may be separated by the separator wall 215 configured to extend between the first row of battery cells and the second row of battery cells. The separator wall 215 thus defines, at least in part the first-row space 201 and the second-row space 202.

In the present example, the separator wall 215 is configured to be secured to the end-plates 204-207 as part of the half-lap joint, as shown in example figure 10.

The separator wall 215 includes a first flange at a first end configured to be received within the first half-lap joint and a second flange 1002 at an opposed second end configured to be received within the second half-lap joint 1003.

The second flange 1002 shown in Figure 10 extends perpendicular to the remainder of the separator wall at an end thereof. The separator wall 215 is configured to extend partially between the second first-row end plate 205 and the second second-row end plate 207 and the flange 1002 is configured to engage between a cheek 1004 of the reduced thickness part of the half-lap joint of one of the end plates and a cheek 1005 of the reduced thickness part of the half-lap joint of the other of the end plates.

The half-lap joint may be configured to receive a fixing 1006, such as one or more rivets, that extends through both end-plates and the flange 1002 to secure them together.

In other examples, there may be provided further rows of battery cells and thus further separator walls.

Returning to the example method described with reference to Figure 5, the steps of receiving 501 the battery assembly housing and loading 502 the battery assembly housing with the plurality of battery cells may comprise loading the battery assembly housing with at least one row of the plurality of battery cells prior to installing all of the walls 204-209, 215 of the walled tray 200 on the cooling plate 203.

In particular, the method may comprise compressing a sub-assembly of the first row of the plurality of cells, the first first-row end plate 204 and the second first-row end plate 205, at least in part by positioning and affixing the first first- row end plate 204 on the cooling plate 203 by the bracket 601 and affixing the second first-row end plate 205 on the cooling plate 203 by the bracket 602 with the first row of the plurality of cells therebetween.

The method may include coupling the first side wall 208 to the first first-row end plate 204; and coupling the first side wall 208 to the second first-row end plate 205; and, optionally, coupling the first side wall 208 to the cooling plate 203.

The method may include coupling the separator wall 215 to the first first-row end plate 204 and to the second first-row end plate 205 to partially enclose the first row of battery cells to clamp the end plates together with the row of battery cells therebetween. In some examples, the method includes coupling the first side wall 208 to the cooling plate 203 after installing the separator wall 215.

The method may include compressing a second sub-assembly of the second row of the plurality of cells, the first second-row end plate 206 and the second second-row end plate 207, at least in part by positioning and affixing the first second-row end plate 206 on the cooling plate 203 by the bracket 603 and affixing the second second-row end plate 207 on the cooling plate 203 by the bracket 604 with the second row of the plurality of cells therebetween.

The method may include coupling the second side wall 209 to the first second- row end plate 206; and coupling the second side wall 209 to the second second-row end plate 207; and coupling the second side wall 209 to the cooling plate 203.

Claims

1. A battery assembly housing configured to receive a plurality of battery cells at respective predetermined locations wherein each battery cell includes a vent, wherein the battery assembly housing includes a cover plate having a slot that forms an opening in the cover plate and wherein the slot is configured and arranged to span a plurality of the vents of the battery cells, and wherein the slot includes a foam to one or more of absorb energy, receive material and receive gases ejected from one or more of the vents of the plurality of battery cells in the event of thermal runaway.

2. The battery assembly housing of claim 1, wherein the cover plate includes a plurality of ribs that extend between a first longitudinal side of the slot and a second longitudinal side of the slot to divide the slot into a plurality of sub-sections, each sub-section comprising an opening in the cover plate for one of a respective vent or a plurality of adjacent vents, wherein the ribs extend, at least in part, through the foam.

3. The battery assembly housing of claim 2, wherein at least one of the plurality of ribs is configured to be spaced from the plurality of battery cells to provide a gap between said at least one of the plurality of ribs and the plurality of battery cells, wherein the gap is at least partially filled by the foam.

4. The battery assembly housing of any preceding claim, wherein the extent of the foam is defined by a size of the slot in the cover plate.

5. The battery assembly housing of any preceding claim, wherein a thickness of the foam is less than a thickness of the cover plate.

6. The battery assembly housing of any preceding claim, wherein the battery assembly housing is configured to receive a plurality of prismatic battery cells.

7. The battery assembly housing of any preceding claim, wherein the cover plate includes a peripheral edge that defines the slot and that is configured to seal against the plurality of battery cells when loaded in the battery assembly housing and wherein one of: the peripheral edge that defines the slot includes an adhesive configured to adhere and seal against the plurality of battery cells when mounted in the battery assembly housing; and the peripheral edge that defines the slot includes a seal configured to abut and seal against the plurality of battery cells when mounted in the battery assembly housing.

8. The battery assembly housing of any preceding claim, comprising: a cooling plate configured to form a base of the battery assembly housing and configured to receive the plurality of battery cells side by side in at least one row, a first end plate coupled to the cooling plate at a first edge and positioned to lie adjacent a first end the at least one row of battery cells, a second end plate coupled to the cooling plate at an opposed, second edge and positioned to lie adjacent an opposed, second end of the at least one row of battery cells, a first side wall coupled to the cooling plate and configured to lie adjacent a plurality of sides of the at least one row of battery cells; a second side wall coupled to the cooling plate, opposed the first side wall; and wherein the cover plate is received on the first and second end plate and the first and second side walls.

9. The battery assembly housing of claim 8, wherein at least one of the first end plate and the second end plate are coupled to the cooling plate at least in part by a bracket that is affixed to the cooling plate by a thermal adhesive.

10. The battery assembly housing of claim 9, wherein said at least one of the first end plate and the second end plate is configured to receive an electronic control unit for controlling the plurality of battery cells that are to be mounted in the battery assembly housing and wherein the bracket is of a thermally conductive material to thermally couple, and thereby provide cooling for, the electronic control unit when in use.

11. A battery assembly comprising the battery assembly housing of any preceding claim including the plurality of battery cells loaded therein.

12. A method of forming a battery assembly comprising: receiving a battery assembly housing; loading the battery assembly housing with a plurality of battery cells at respective predetermined locations wherein each battery cell includes a vent, placing a cover plate over the plurality of battery cells, wherein the cover plate includes a slot that forms an opening in the cover plate and wherein the slot is configured and arranged to span a plurality of the vents of the battery cells; and applying a foam into the slot, the foam configured to one or more of absorb energy, receive material and receive gases ejected from one or more of the vents of the plurality of battery cells in the event of thermal runaway.

13. The method of claim 12, wherein the foam comprises an expanding foam material configured to expand to at least partially fill the slot once applied therein.

14. The method of claim 12 or claim 13, wherein the cover plate includes a peripheral edge that defines the slot and that is configured to seal against the plurality of battery cells loaded in the battery assembly housing, wherein the method includes one or both of applying adhesive to the peripheral edge and applying adhesive to the plurality of battery cells at locations where the peripheral edge seals against the plurality of battery cells.

15. The method of any one of claims 12 to 14, wherein the cover plate includes a plurality of ribs that extend between a first longitudinal side of the slot and a second longitudinal side of the slot to divide the slot into a plurality of sub-sections, each sub-section comprising an opening in the cover plate for one of a respective vent or a plurality of adjacent vents; and wherein at least one of the plurality of ribs is spaced from the peripheral edge to provide a gap between said at least one of the plurality of ribs and the plurality of battery cells; and wherein the foam comprises an expanding foam; wherein the method comprises: applying the expanding foam into the slot such that it flows through said gap so that the foam is applied to a plurality of said sub-sections.

16. A battery assembly housing configured to receive a plurality of battery cells, comprising: a cooling plate configured to form a base of the battery assembly housing and configured to receive the plurality of battery cells, a plurality of walls extending from and coupled to a first side of the cooling plate; wherein at least one of the plurality of walls is coupled to the cooling plate at least in part by a bracket that is affixed to the cooling plate by an adhesive.

17. The battery assembly housing of claim 16, wherein the adhesive comprises a thermal adhesive.

18. The battery assembly housing of claim 16 or claim 17, wherein said at least one of the plurality of walls comprises an outer wall and an inner wall connected by a plurality of webs, wherein the bracket is configured to structurally couple said at least one of the plurality of walls to the cooling plate to resist a swelling force generated by swelling of the plurality of battery cells when loaded in the battery assembly housing.

19. The battery assembly housing of claim 17, wherein said at least one of the plurality of walls is configured to receive an electronic control unit for controlling the plurality of battery cells that are to be mounted in the battery assembly housing and wherein the bracket is of a thermally conductive material to thermally couple the electronic control unit to the cooling plate via the thermal adhesive to thereby provide cooling for said electronic control unit when in use.

20. The battery assembly housing of claim 19, wherein said at least one of the plurality of walls comprises an outer wall and an inner wall connected by a plurality of webs, wherein the bracket is coupled to the outer wall and is received between the plurality of webs and wherein the electronic control unit is also coupled to the outer wall.

21. The battery assembly housing of claim 18 or claim 20, wherein said at least one of the plurality of walls includes a slot between the webs to slidably receive the bracket therein to thereby locate the at least one of the plurality of walls in a predetermined location relative to the cooling plate.

22. The battery assembly housing of any one of claims 16 to 21, wherein the cooling plate is configured to receive the plurality of battery cells side by side in a row and wherein the plurality of walls comprise: a first end plate coupled to the cooling plate at a first edge and positioned adjacent a first end the row of battery cells, a second end plate coupled to the cooling plate at an opposed, second edge and positioned adjacent an opposed, second end of the row of battery cells, a first side wall coupled to the cooling plate and positioned adjacent a plurality of sides of the row of battery cells; a second side wall coupled to the cooling plate, opposed the first side wall; and wherein the bracket is configured to couple at least one of the first end plate and the second end plate to the cooling plate.

23. The battery assembly housing of any one of claims 16 to 21, wherein the cooling plate is configured to receive the plurality of battery cells arranged in a first row of battery cells arranged side by side and a second row of battery cells arranged side by side and wherein the plurality of walls comprise: a first first-row end plate coupled to the cooling plate at a first edge and positioned adjacent a first end of the first row of battery cells, a second first-row end plate coupled to the cooling plate at an opposed, second edge and positioned adjacent an opposed, second end of the first row of battery cells, a first second-row end plate coupled to the cooling plate at the first edge and positioned adjacent a first end of the second row of battery cells, a second second-row end plate coupled to the cooling plate at the opposed, second edge and positioned adjacent an opposed, second end of the second row of battery cells, a first side wall coupled to the cooling plate and positioned adjacent a plurality of sides of the first row of battery cells; a second side wall coupled to the cooling plate, opposed the first side wall and positioned adjacent a plurality of sides of the second row of battery cells; and wherein the bracket is configured to couple at least one of the first and second first-row end plates and the first and second second-row end plates to the cooling plate.

24. The battery assembly housing of claim 23, wherein a plurality of brackets are provided to couple a respective one of each the first and the second first- row end plates and the first and the second second-row end plates to the cooling plate.

25. The battery assembly housing of claim 23 or claim 24, wherein the first first-row end plate and the first second-row end plate are coupled together by a first half-lap joint; and the second first-row end plate and the second second-row end plate are coupled together by a second half-lap joint.

26. The battery assembly housing of claim 25, wherein the battery assembly housing includes a separator wall arranged between the first row of battery cells and the second row of battery cells, wherein the separator wall includes a first flange at a first end configured to be received within the first half-lap joint and a second flange at an opposed second end configured to be received within the second half-lap joint.

27. The battery assembly housing of claim 26, wherein the first half-lap joint is configured to receive a fixing that extends through the first first-row end plate, the first flange and the first second-row end plate to secure them together; and the second half-lap joint is configured to receive a fixing that extends through the second first-row end plate, the second flange and the second second-row end plate to secure them together.

28. The battery assembly housing of any one of claims 22 to 25, wherein the first side wall is coupled by fixings to the first first-row end plate, the second first-row end plate and the cooling plate; and the second side wall is coupled by fixings to the first second-row end plate, the second second-row end plate and the cooling plate.

29. The battery assembly housing of any one of claims 16 to 28, wherein the cooling plate includes a plurality of channels therein to receive a flow of coolant between a first port and a second port.

30. The battery assembly housing of any one of claims 16 to 29, wherein a cover plate is received on the plurality of walls opposite the cooling plate to define an enclosed volume for receiving said plurality of battery cells.

31. The battery assembly housing of claim 30, wherein the plurality of battery cells are to be received at respective predetermined locations in the battery assembly housing, wherein each battery cell includes a vent, and wherein the cover plate includes a slot that forms an opening in the cover plate and wherein the slot is configured and arranged to span a plurality of the vents of the battery cells, and wherein the slot includes a foam to one or more of absorb energy, receive material and receive gases ejected from one or more of the vents of the plurality of battery cells in the event of thermal runaway.

32. A battery assembly comprising the battery assembly housing of any one of claims 16 to 31 including the plurality of battery cells loaded therein.