JP6390062B2 - Battery module - Google Patents

Description

  The present invention relates to a battery main body and a battery module having a casing that covers the battery main body from the outside.

  Conventionally, in a battery module (assembled battery) in a form in which a plurality of battery cells (single cells) are housed in a housing case, an electrolyte solution when the internal pressure or temperature of the battery cell rises abnormally due to an internal short circuit or the like There is known one that can suppress or extinguish the fire of the fire (see, for example, Patent Document 1).

International Publication No. 2012/014348

  By the way, the battery module of the said patent document 1 is aiming at safety design by incorporating a digestion system with respect to the whole storage case of a battery module. However, abnormal occurrence events such as internal short circuit and overcharge of battery cells are extremely rare as the frequency of occurrence events, and it is not possible to provide an inert fluid for digestion and an accompanying control mechanism (for example, a pressure detection mechanism). For example, it is not a good idea under conditions where installation space is limited such as an electric vehicle, and is not practical from the viewpoint of cost effectiveness.

  An object of the present invention is to provide a battery module capable of preventing the spread of fire to adjacent battery cells with a more compact structure.

According to the first aspect of the present invention, a battery module includes a battery body, a housing that covers the battery body from the outside, and an opening formed in the housing so as to close the opening. A battery cell having a safety valve that discharges the gas from the housing through the opening when high-temperature gas is generated, and an exhaust path that houses the battery cell and guides the gas from the opening to the outside of the housing case And a combustion inhibitor disposed in the exhaust path, and the exhaust path has a cylindrical shape that connects the outside of the storage case and the opening in the vertical direction. Features.

  According to such a configuration, when the safety valve is cleaved due to the abnormality of the battery and the high temperature gas is discharged from the inside of the battery, the high temperature gas is discharged to the outside through the exhaust path, and the high temperature is generated by the combustion inhibitor. It is possible to suppress further increase in the temperature of the gas. Thereby, the battery module which can prevent the fire spread to the adjacent battery cell with a more compact structure can be provided.

  According to such a configuration, when the safety valve is cleaved due to the abnormality of the battery and the high temperature gas is discharged from the inside of the battery, the high temperature gas is guided upward in the vertical direction, so that the heat is transmitted to the adjacent battery. Can be suppressed.

  In the battery module, the combustion inhibitor may be applied to an inner peripheral surface of the exhaust path.

  According to such a configuration, when the high-temperature gas is guided to the outside by the exhaust path, the high-temperature gas is further heated by contacting the combustion inhibitor applied to the inside of the cylindrical exhaust path. Can be suppressed.

  The battery module includes a plate-like member attached to the inside of the exhaust path and having a plurality of through holes penetrating in the extending direction of the exhaust path while having a main surface orthogonal to the extending direction of the exhaust path. And the said combustion inhibitor may be apply | coated to at least one part of the said plate-shaped member.

  According to such a configuration, since the combustion inhibitor can be brought into contact with the high-temperature gas flowing through the central portion of the exhaust path, the effect of suppressing the combustion of the combustible gas contained in the high-temperature gas is increased. Can do.

  In the battery module, the combustion inhibitor may be enclosed in a capsule that is disposed on the exhaust path and melted by the high-temperature gas.

  According to such a configuration, the capsule is melted by the high-temperature gas and the combustion suppressant inside the capsule and the high-temperature gas are mixed, thereby preventing the high-temperature gas from further increasing. it can.

In the battery module, the exhaust path may be narrowed toward the downstream side of the gas.
According to such a configuration, since the high-temperature gas and the combustion inhibitor are in contact with each other, the temperature of the high-temperature gas can be further lowered.

  According to the present invention, when the safety valve is cleaved due to the abnormality of the battery and the high temperature gas is discharged from the inside of the battery, the high temperature gas is discharged to the outside through the exhaust path, and the high temperature gas is discharged by the combustion inhibitor. Can be further prevented from becoming a high temperature. Thereby, the battery module which can prevent the fire spread to the adjacent battery cell with a more compact structure can be provided.

It is a perspective view which shows the battery module of 1st embodiment of this invention. It is a perspective view which shows the internal structure of the battery module of 1st embodiment of this invention. It is a perspective view which partially fractures | ruptures and shows the structure of the battery cell provided in the battery module of 1st embodiment of this invention. It is a fragmentary sectional view which shows the structure of the battery module of 1st embodiment of this invention. It is a fragmentary sectional view which shows the structure of the battery module of 2nd embodiment of this invention. It is a top view of the mesh board of the modification of the battery module of 2nd embodiment of this invention. It is a fragmentary sectional view which shows the structure of the battery module of 3rd embodiment of this invention.

(First embodiment)
The battery module 1 of 1st embodiment of this invention is demonstrated. FIG. 1 is a perspective view showing a battery module 1 of the present embodiment. FIG. 2 is a perspective view showing the internal structure of the battery module 1. FIG. 3 is a perspective view showing a partially broken configuration of the battery cell 2 provided in the battery module 1.
As shown in FIGS. 1 and 2, the battery module 1 includes a plurality of battery cells 2, a plurality of battery cells 2 housed therein, and a housing case 22 in which a cooling fluid flows around the battery cells 2, have. The housing case 22 includes a cubic housing case body 23 having an open top, and a module cover 24 that covers the top of the housing case body 23.

  The module cover 24 has a high temperature exhaust gas generated in the battery cell 2 when an abnormality occurs in the plurality of cooling air ventilation holes 27 for allowing the cooling fluid C for cooling the battery cell 2 to pass therethrough. A gas discharge hole 28 for discharging (combustible gas, combustion gas) is formed.

  The terminals of the plurality of battery cells 2 housed in the housing case 22 are electrically connected in series or in parallel by the bus bar 12. In addition, the storage case 22 is provided with a control unit 15 that controls charging and discharging of each battery cell 2.

As shown in FIG. 3, the battery cell 2 includes a positive electrode 4 and a negative electrode 5 that are alternately stacked battery bodies, a hollow container-shaped housing 3 that covers the positive electrode 4 and the negative electrode 5 from the outside, a positive electrode 4 and a negative electrode. An insulating solution capable of passing through the electrolytic solution 6 (filled in the battery cell container) disposed between the positive electrode 4 and the negative electrode 5 and the electrolytic solution 6 disposed in the casing 3 so as to be in contact with 5 The separator 7 is provided with a terminal 8 and a safety valve 11 formed on the housing 3.
In addition, although the gas outlet tube 30 (refer FIG. 4) mentioned later is joined to the housing | casing 3 of the battery cell 2 of this embodiment, illustration of the gas outlet tube 30 is abbreviate | omitted in FIG.

  In the present embodiment, the battery cell 2 is a lithium ion secondary battery, and a nonaqueous electrolytic solution is employed as the electrolytic solution 6. For example, examples of the non-aqueous electrolyte include organic electrolytes in which an electrolyte is contained in an organic solvent.

  The separator 7 is attached to the negative electrode 5 by laminating. The separator 7 may be laminated so as to cover the positive electrode 4 instead of the negative electrode 5. Further, the separator 7 may simply be interposed between the positive electrode 4 and the negative electrode 5 as long as the separator 7 is interposed between the positive electrode 4 and the negative electrode 5 so that the positive electrode 4 and the negative electrode 5 do not contact each other.

  The terminal 8 formed in the housing 3 includes a positive electrode terminal 9 connected to the positive electrode 4 and a negative electrode terminal 10 connected to the negative electrode 5. In the present embodiment, the positive electrode terminal 9 and the negative electrode terminal 10 are arranged on the lid member 3a of the housing 3 and are provided so as to protrude from the lid member 3a.

The safety valve 11 is a valve that discharges gas existing in the housing 3 to the outside when the battery cell 2 is in an overheated state, for example. The safety valve 11 is disposed so as to maintain airtightness with the opening 13 so as to block the opening 13 (see FIG. 4) formed in the lid member 3a of the housing 3, and is opened at a predetermined pressure or temperature or higher. It is formed to be in an open state. That is, when the safety valve 11 is in an open state, the inside and outside of the housing 3 are in a communication state.
For example, the safety valve 11 may be appropriately selected from a well-known configuration such as a valve opened by being destroyed by the internal pressure of the casing 3 of the battery cell 2 in an overheated state or a valve opened by melting the thermowax. it can. In the present embodiment, the safety valve 11 is disposed between the positive terminal 9 and the negative terminal 10.

  As shown in FIG. 2, the housing case 22 is a container-like member that houses a plurality of battery cells 2 with a gap between them. As shown in FIG. 4, a cooling fluid C for cooling each battery cell 2 flows in the housing case 22. In the present embodiment, as the cooling fluid C, for example, air (outside air) outside the housing case 22 is taken into the housing case 22 by a fan or natural convection and used.

  As shown in FIG. 4, each battery cell 2 is provided with a gas outlet pipe 30 that functions as an exhaust path for high-temperature exhaust gas. The gas outlet pipe 30 is a cylindrical chimney-like member that hermetically connects the gas discharge hole 28 formed in the module cover 24 and the opening 13 formed in the housing 3 of the battery cell 2. The gas outlet pipe 30 guides the high temperature exhaust gas to the outside of the module cover 24 when the safety valve 11 is opened.

  The gas outlet pipe 30 has a cylindrical shape extending in the vertical direction. The gas outlet pipe 30 is formed so that the diameter decreases as it goes upward. In other words, the gas outlet pipe 30 is formed in a conical shape (tapered shape) that narrows toward the downstream side of the high-temperature exhaust gas.

  The gas outlet pipe 30 is formed so that the inner diameter of the lower end of the gas outlet pipe 30 is larger than that of the safety valve 11. The gas outlet pipe 30 is attached to the lid member 3 a so that the lower end surrounds the safety valve 11. The lower end of the gas outlet pipe 30 is joined to the cover member 3a around the opening 13 over the entire circumference by, for example, welding or an adhesive.

The upper end of the gas outlet pipe 30 is connected to the gas discharge hole 28 of the module cover 24. That is, the high temperature exhaust gas discharged when the safety valve 11 is opened is discharged from the gas discharge hole 28 of the module cover 24 via the gas outlet pipe 30.
The gas outlet pipe 30 has such a length that the upper end of the gas outlet pipe 30 is substantially flush with the upper surface of the module cover 24.

  As the material for the gas outlet tube 30 and the module cover 24, flame retardant plastic such as polyvinyl chloride, polycarbonate, fluororesin (polyvinylidene fluoride, Teflon (registered trademark)), polyphenylene oxide, flame retardant EP rubber, etc. are used. Is possible.

  A combustion inhibitor 19 (combustion chain inhibitor) is applied to the inner peripheral surface 30 a of the gas outlet pipe 30. Specifically, a coating material in which the combustion inhibitor 19 is mixed is applied to the inner peripheral surface 30 a of the gas outlet pipe 30. The combustion inhibitor 19 is applied to the front surface of the inner peripheral surface 30 a of the gas outlet pipe 30. The combustion inhibitor 19 may be applied to a part of the inner peripheral surface 30 a of the gas outlet pipe 30.

  The combustion inhibitor 19 is a substance that generates a nonflammable gas (inert gas) by thermal decomposition when heated to a predetermined temperature or higher. Specifically, the combustion inhibitor 19 is a substance that generates nitrogen or carbon dioxide by being thermally decomposed.

As the combustion inhibitor 19, Halon 2402 (dibromotetrafluoroethane, chemical formula: C ₂ Br ₂ F ₄ , melting point −110.3 ° C., boiling point 47.35 ° C., liquid at room temperature) as a liquid halide, halon 1011 ( CH ₂ BrCl, melting point −86.5 ° C., boiling point 68.1 ° C., yellow liquid at room temperature), inorganic powder ammonium dihydrogen phosphate (chemical formula: NH ₄ H ₂ PO ₄ , ABC powder fire extinguishing agent) component), diammonium hydrogen phosphate (chemical _{formula: (NH 4) 2 HPO 4} , decomposition below 100 ° C. melting point, white crystalline powder), sodium ammonium hydrogen phosphate tetrahydrate (chemical _formula: NaNH 4 _HPO 4 · 4H ₂ O, a white crystalline powder), sodium bicarbonate (formula: NaHCO ₃₎ and potassium bicarbonate (Manabu formula: KHCO _3, Lord BC dry chemical Min), ammonium bicarbonate _(Formula: NH 4 HCO _3, the solid decomposition at 58 ° C., powdered solid) and ammonium carbamate _(Formula: NH 2 COONH _4, ammonium carbonate is a mixture of powdered solid), ferrous sulfate・ Heptahydrate (scientific formula: FeSO ₄ · 7H ₂ O, melting point 64 ° C., boiling point 90 ° C., pale blue green crystal), ammonium sulfate (chemical formula: (NH ₄ ) ₂ SO ₄ , melting point 280 ° C., white hygroscopic Crystal or granule), melamine cyanurate (organic salt of melamine and cyanuric acid, chemical formula: C ₃ H ₆ N ₆ .C ₃ H ₃ N ₃ O ₃ , sublimation at 350-400 ° C.), 1,3 , 5-triazine (chemical formula: C ₃ H ₃ N ₃ , melting point 80 ° C., boiling point 114 ° C.) and other guanidines (chemical formula: CH ₅ N ₃ , melting point 50 ° C.) Nidin compounds and the like can be used.
Furthermore, hydroquinone such as polymerization inhibitor, p-methoxyphenol, 2,2,6,6-tetramethylpiperidinyl-1-oxyl (TEMPO), 4-hydroxy-2,2,6,6-tetramethylpi Peridinyl-1-oxyl, triphenyl ferdazyl and the like can also be used.

  As shown in FIG. 2, the bus bar 12 of this embodiment is arranged so that the bus bar 12 does not interfere with the gas outlet pipe 30. Specifically, the bus bar 12 is disposed so as to extend in the longitudinal direction L1 of the lid member 3a of the housing 3 or in the direction L2 orthogonal to the longitudinal direction of the lid member 3a of the housing 3. 3 does not extend in a direction that obliquely intersects the longitudinal direction L1 of the upper lid.

Next, the operation of the battery module 1 will be described.
During operation of the battery module 1, the battery cell 2 generates heat due to charge / discharge. At normal times, the heat of the battery cell 2 is exhausted to the outside of the storage case 22 by the cooling fluid C that convects in the storage case 22 (in this embodiment, outside air introduced into the storage case 22).

  By the way, it is conceivable that part or all of the battery cells 2 housed in the housing case 22 are overheated when the battery module 1 is out of order (abnormal). This may be due to a short circuit in each battery cell 2 or failure due to poor circulation of the cooling fluid C. In such a case, there is a possibility that high-temperature gas accumulates in the battery cell 2 without the heat radiation in each battery cell 2 being in time.

  Here, when the battery cell 2 is overheated, when the internal pressure of the battery cell 2 near the safety valve 11 exceeds a predetermined pressure, or when the internal temperature of the battery cell 2 near the safety valve 11 exceeds a predetermined temperature. Through the safety valve 11, the gas obtained by vaporizing the electrolyte 6 is discharged outside the housing 3 and outside the housing case 22 through the gas outlet tube 30. For example, when the battery cell 2 is in an overheated state, the gas released to the outside of the housing 3 through the safety valve 11 becomes a high-temperature gas.

  Here, the high temperature exhaust gas (in FIG. 4, the direction in which the high temperature exhaust gas flows is indicated by an arrow with a symbol X) is a combustion inhibitor applied to the inner peripheral surface 30 a of the gas outlet pipe 30. It is discharged to the outside of the housing case 22 while being in contact with 19. The combustion inhibitor 19 in contact with the high-temperature exhaust gas is thermally decomposed by the heat of the high-temperature exhaust gas, and the nonflammable gas is filled in and around the gas.

  According to the embodiment, when the safety valve 11 is cleaved due to an abnormality in the battery cell 2 and the high temperature exhaust gas is discharged from the inside of the battery cell 2, the high temperature exhaust gas is discharged to the outside through the gas outlet pipe 30 that functions as an exhaust path. Is done. At this time, when the high temperature exhaust gas comes into contact with the combustion inhibitor 19 applied to the inner peripheral surface 30 a of the gas outlet pipe 30, it is possible to prevent the high temperature exhaust gas from becoming further hot. Thereby, the battery module 1 which can suppress combustion of the combustible gas contained in high temperature exhaust gas by a more compact structure, and can prevent the fire spread to the adjacent battery cell 2 can be provided.

  Further, since the gas outlet pipe 30 has a cylindrical shape that connects the outside of the housing case 22 and the opening 13 of the battery cell 2 in the vertical direction, the safety valve 11 is cleaved due to an abnormality in the battery cell 2 and the battery cell 2 inside. When the high temperature exhaust gas is discharged from the high temperature exhaust gas, the high temperature exhaust gas is guided upward in the vertical direction, so that it is possible to suppress heat from being transmitted to the adjacent battery cells 2.

  Further, since the gas outlet pipe 30 is narrowed toward the downstream side of the high temperature exhaust gas, the high temperature exhaust gas and the combustion inhibitor 19 are more in contact with each other, so that the temperature of the high temperature exhaust gas can be further lowered.

(Second embodiment)
Hereinafter, a battery module according to a second embodiment of the present invention will be described with reference to the drawings. In the present embodiment, differences from the first embodiment described above will be mainly described, and description of similar parts will be omitted.
As shown in FIG. 5, the battery module 1 </ b> B of the present embodiment is characterized by having a plurality of mesh plates 32, each having a plurality of mesh plates 32 coated with a paint mixed with the combustion inhibitor 19.

  The mesh plate 32 is a circular plate-like member formed of a mesh metal (metal mesh), and is arranged inside the gas outlet tube 30 so that the main surface is orthogonal to the extending direction of the gas outlet tube 30. Yes. In other words, the mesh plate 32 has a plurality of through holes 33 penetrating in the extending direction of the gas outlet pipe 30.

  A combustion inhibitor 19 is applied to at least a part of the mesh plate 32. The combustion inhibitor 19 is preferably applied to a portion corresponding to the inner peripheral surface of the through hole 33. In addition, although the combustion inhibitor 19 is not apply | coated to the internal peripheral surface 30a of the gas outlet tube 30 of this embodiment, it is good also as a structure applied.

According to the above embodiment, the combustion inhibitor 19 can be brought into contact with the high-temperature exhaust gas flowing through the central portion of the gas outlet pipe 30 functioning as an exhaust path, so that combustion of the combustible gas contained in the high-temperature exhaust gas is suppressed. The effect can be increased.
Further, since the gas outlet pipe 30 is formed in a conical shape, the mesh plate 32 can be prevented from being blown above the housing case 22 by the wind pressure of the high-temperature exhaust gas.

(Modification of the second embodiment)
As shown in FIG. 6, the mesh plate 32 </ b> B is not limited to a mesh metal, and may be formed of a punching metal. However, when punching metal is employed, it is preferable to increase the aperture ratio in order to reduce pressure loss. Further, the shape of the through hole 33B is not limited to a circular shape, and may be a hexagonal shape or a square hole.

(Third embodiment)
Hereinafter, a battery module according to a third embodiment of the present invention will be described with reference to the drawings. In the present embodiment, differences from the second embodiment described above will be mainly described, and description of similar parts will be omitted.
As shown in FIG. 7, in the battery module 1 </ b> C of the present embodiment, at least one capsule 34 (microcapsule) containing the combustion inhibitor 19 is disposed between a pair of mesh plates 32 that are separated in the vertical direction. Yes. That is, the combustion inhibitor 19 is disposed on the exhaust path. The capsule 34 is formed of a material that is melted by high-temperature exhaust gas.
In addition, although the combustion inhibitor 19 is not apply | coated to the mesh board 32 of this embodiment, the effect of combustion suppression may be improved by apply | coating the combustion inhibitor 19 to at least one part of the mesh board 32. .

  The capsule 34 is a container that releases the combustion inhibitor 19 to the outside when heated to a predetermined temperature or higher. As the capsule 34, for example, a container that melts at a predetermined temperature or higher, a container that breaks at a predetermined temperature or higher, a sealed container that can be broken by the pressure of noncombustible gas generated when the combustion inhibitor 19 is thermally decomposed, or the like can be used.

  Examples of the material of the capsule 34 include natural polymers (proteins such as collagen and gelatin, polysaccharides such as cellulose and starch, natural rubber, and mixtures of gelatin-arabic gum, gelatin-gellan gum) and synthetic polymers (polystyrene, polyvinyl alcohol). , Carboxymethylcellulose, polyvinylpyrrolidone, polyamide, polyester, polyurethane, etc.) are preferred.

The material of the capsule 34 does not necessarily have to be a polymer, and waxes and inorganic compounds can also be used.
The shape of the capsule 34 is usually spherical, but other shapes such as an ellipsoid and a polyhedron can also be used. The maximum outer shape of the capsule 34 (the dimension that is measured the largest among the dimensions of the capsule 34) can be several micrometers to several millimeters. The thickness of the outer wall of the capsule 34 is about 1/10 to 1/100 of the maximum outer shape, and can be 0.1 micrometer to 0.1 millimeter.
However, the maximum outer shape of the capsule 34 needs to be larger than the size of the through hole 33 of the mesh plate 32. Further, the size and number of capsules 34 need to be set so as not to block the exhaust path and prevent the discharge of high-temperature exhaust gas.

As the combustion suppressing agent 19 enclosed in the capsule 34, not only a solid but also a fire extinguishing agent such as a liquid fire extinguishing agent Novec (registered trademark) 1230 (manufactured by 3M) can be used.
Further, as the capsule 34, a capsule 34 obtained by painting and solidifying around the solid combustion inhibitor 19 with a paste-like substance can also be adopted.

  According to the above-described embodiment, the capsule 34 is melted by the high-temperature exhaust gas, and the combustion suppressant 19 inside the capsule 34 and the high-temperature exhaust gas are mixed, so that the high-temperature exhaust gas can be prevented from becoming further hot. .

The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in each of the above-described embodiments, the gas outlet tube 30 has a cylindrical shape, but the present invention is not limited to this, and the gas outlet tube 30 may have a prismatic shape.
Further, the gas outlet pipe 30 does not necessarily have a shape that narrows toward the downstream side of the high-temperature exhaust gas, and may have a cylindrical shape whose diameter does not change from the upper end to the lower end.

DESCRIPTION OF SYMBOLS 1,1B, 1C Battery module 2 Battery cell 3 Case 3a Lid member 4 Positive electrode 5 Negative electrode 6 Electrolyte 7 Separator 8 Terminal 9 Positive electrode terminal 10 Negative electrode terminal 11 Safety valve 12 Bus bar 13 Opening 15 Control part 19 Combustion inhibitor 22 Storage case 23 Housing case body 24 Module cover 27 Cooling air ventilation hole 28 Gas exhaust hole 30 Gas outlet pipe (exhaust path)
30a Inner peripheral surface 32, 32B Mesh plate 33, 33B Through hole 34 Capsule C Cooling fluid

Claims (5)

A battery main body, a casing that covers the battery main body from the outside, and a casing that is provided so as to close an opening formed in the casing so that high-temperature gas is generated from the battery main body. A battery cell having a safety valve for discharging the gas from the body;
A storage case in which an exhaust path for guiding the gas from the opening to the outside of the storage case is formed while storing the battery cell;
A combustion inhibitor disposed in the exhaust path ,
The exhaust path is a battery module having a cylindrical shape that connects the outside of the housing case and the opening in a vertical direction . The battery module according to claim 1 , wherein the combustion inhibitor is applied to an inner peripheral surface of the exhaust path. A plate-like member attached to the inside of the exhaust path and having a plurality of through holes penetrating in the extending direction of the exhaust path, with a main surface orthogonal to the extending direction of the exhaust path
The burn suppressing agent, cell module according to claim 1 or claim 2 is applied to at least a portion of the plate-like member. The burn suppressing agent, battery module according to any one of claims 1 to 3 which is enclosed in the capsule for melting the disposed on the exhaust passage by the gas of the high temperature. The battery module according to any one of claims 1 to 4 , wherein the exhaust path is narrowed toward a downstream side of the gas.

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