WO2011000267A1

WO2011000267A1 - Method for manufacturing cylindrical battery capable of improving battery capacity

Info

Publication number: WO2011000267A1
Application number: PCT/CN2010/074081
Authority: WO
Inventors: 任灿; 王春光; 陈保同
Original assignee: 深圳市比克电池有限公司
Priority date: 2009-06-29
Filing date: 2010-06-18
Publication date: 2011-01-06
Also published as: WO2011000239A1; CN101938012B; CN101938012A

Abstract

A method for manufacturing cylindrical battery capable of improving the battery capacity, includes following steps: increasing the height h1 of an electrode group (13) by △h and packing the electrode group (13) into a battery can (11); forming an annular groove (112) with height h2 at the open end of the battery can (11); connecting a combination cap (12) with height h3 with the electrode group (13) and placing the combination cap (12) above the annular groove (112) with height h2, then sealing the battery can (11); exerting force F2 to compress the annular groove (112) and combination cap (12) with total height h2+h3 by △h, so as to improve the battery capacity by increasing height of the electrode group (13) △h without changing battery standard height. The method of the invention reduces the height of the annular groove (112) by compression process, therefore increases the space holding the electrode group (13) within the battery.

Description

Cylindrical battery manufacturing method capable of improving battery capacity

Technical field

The present invention relates to the field of battery manufacturing, and in particular to a method of manufacturing a cylindrical battery.

Background technique

Referring to FIG. 1 to FIG. 7 , the cylindrical battery generally includes a battery cylinder 1 , a battery pole group 3 having a height h1 formed by winding in the battery cylinder 1 , a combined cap 2 mounted on the top end of the battery cylinder 1 , and A cylindrical support frame 4 and the like are disposed in the middle of the battery pole group 3. The bottom of the battery cylinder 1 is usually further provided with a bottom insulating ring 7 for separating the positive/negative electrode terminal 52 from the battery electrode group, and the top of the battery cylinder is provided with insulation for insulating the battery electrode group 3 and the combination cap 2 Top insulation ring 6. The top insulating ring 6 is pressed above the battery pole group 3 and is caught under the annular groove 12 of the height h2 formed on the battery cylinder 1. The center of the top insulating ring 6 is provided with a tab hole through which the upwardly extending negative/positive terminal 51 can pass, the diameter of which is slightly larger than the diameter of the support frame 4 and can accommodate the negative/positive terminal 51. It is also used to put the support frame 4 from the open end of the battery can 1. In the existing cylindrical battery manufacturing process, the annular groove 12 is generally formed by a roll groove process. At the same time as the annular groove 12 is formed, a combination cap for the hook height h3 is formed above the annular groove 12 of the battery cylinder 1. 2 annular wall 11. When the battery is packaged, the combined cap is placed above the top insulating ring 6, while the upwardly extending negative/positive terminal 51 is welded to the combined cap 2, after which the annular wall 11 is bent and pressed against the combined cap by an external force F1. 2 of the outermost insulating seal 22.

Referring to FIG. 7, the specific structure of the prior art combined cap 2 includes a top plate 21 for extracting an electrode, a thermistor 23 for cutting off current in case of overheating, an explosion-proof pressure protection device 24, and welding with the pressure protection device 24. Conductive plate 25. The top plate 21, the thermistor 23, the pressure protection device 24, and the conductive plate 25 are fastened together by an insulating seal 22.

As shown in FIG. 1 to FIG. 6, the specific steps of manufacturing a cylindrical battery in the prior art generally include:

First, the battery cylinder 1 is fabricated. The bottom of the battery cylinder 1 is placed with a bottom insulating ring 7 separating the positive/negative electrode terminal 52 and the battery electrode group 3; and then a battery group of height h1 is placed into the battery cylinder 1. 3. Connect the downward positive/negative lead terminal 52 around the bottom insulating ring 7 to the bottom electrode.

Next, as shown in FIG. 1, the top insulating ring 6 is placed on the upper end surface of the battery pole group 3, and the negative/positive terminal end 51 extending vertically upward passes through the tab hole of the top insulating ring 6.

Thereafter, as shown in FIG. 2, an annular groove 1 having a height h2 is formed on the battery cylinder 1 by a rolling process, and the annular groove 12 forms a flange which is pressed against the top insulating ring 6 inside the battery cylinder 1. (not shown), the flange 1 inside the battery cylinder 1 presses the top insulating ring 6 against the battery pole group 3 while forming the annular wall 11 at the top of the battery cylinder 1.

Next, as shown in FIG. 3, the support frame 4 is inserted through the tab holes on the top insulating ring 6 into the inner center of the battery pole group 3, and forms a close fit with the battery pole group 3.

Finally, the free end of the upwardly extending negative/positive terminal 51 is welded to the bottom of the conductive plate 25 of the combined cap 2, after the electrolyte is injected into the interior of the battery can 1, and the combined cap 2 is placed in the open of the battery can 1. The end (the order of the above steps depends on the specific process), and the annular wall 11 at the top of the battery cylinder 1 surrounds the combined cap and abuts against the insulating seal 22 at the periphery of the combined cap. The annular wall is press-fitted against the insulating sealing member 22 by an external force F1 to obtain a cylindrical battery as shown in FIG.

However, the battery capacity is directly related to the volume of the internally wound battery pole group 3. The volume of the battery pole group 3 is proportional to the height h1 of the battery pole group 3 and the spread width. In the manufacturing method of the existing cylindrical battery, in the limited internal space of the battery cylinder 1, the larger volume includes the battery pole group 3 and the combined cap 2, the height of the battery pole group 3 is h1, and the height of the combined cap 2 is H3. The combined cap 2 takes on many functions such as overheat protection, pressure protection, sealing and insulation, and there are many functional components in the combination. At the same time, the structure of the annular groove 12 having the height h2 for separating the battery pole group 3 and the combined cap 2 also occupies a large internal space of the battery cylinder 1. The current overall height H of various types of batteries is a constant standard value. Generally, the overall height H of the battery is equal to the sum of the height h1 of the battery pole group 3 and the height h2 of the annular groove and the height h3 of the combined cap 2, H= H1+h2+h3. Therefore, in the existing cylindrical battery manufacturing method, the internal space utilization rate of the battery can 1 is low, and the battery capacity needs to be improved in order to meet the demand for large-capacity batteries of electronic products.

technical problem

The technical problem to be solved by the present invention is to make up for the deficiencies of the above prior art, and to provide a cylindrical battery manufacturing method which can fully utilize the internal space of the battery and increase the battery capacity.

Technical solution

The technical problem of the present invention is solved by the following technical solution: a cylindrical battery manufacturing method capable of improving battery capacity, comprising the steps of: loading a battery pole group having a height h1+Δh into a battery cylinder of a cylindrical battery; Forming an annular groove of height h2 at the open end of the battery barrel; placing a combined cap of height h3 above the annular groove in the battery barrel, the combined cap connecting the battery pole set, and fixing the combined cap Sealed on the battery barrel, at this time, the total height of the battery is H + Δh = (h1 + Δh) + h2 + h3, where H is the standard height of the cylindrical battery; pressure (F2) is applied from the sealing end of the battery, The pressure (F2) shortens the (h2+h3) annular groove and the combined cap by Δh, and the height of the annular groove and the combined cap decreases to (h2+h3)', that is, (h2+h3)'=(h2 +h3)-Δh, after compressing the annular groove, the cylindrical battery recovers to the standard height H = (h1 + Δh) + (h2+h3)' = (h1 + Δh) + (h2+h3) - Δh.

Wherein, the battery cylinder forms an annular wall at an open end above the annular groove, and after the combined cap is placed over the annular groove of the battery cylinder, the annular wall is bent inward by an external force, and the bent annular wall will be The combined cap is fixedly sealed in the battery barrel.

Specifically, before the battery pole assembly is assembled into the battery cylinder, an insulating ring is disposed at the bottom of the battery cylinder, and a positive/negative electrode terminal is drawn downward from the battery pole group, and the positive/negative electrode terminal bypasses the insulation. The ring is in contact with the bottom of the battery barrel.

An insulating ring is disposed on an upper portion of the battery pole group, and a negative/positive terminal is drawn upward from the battery pole group, and the negative/positive terminal leads through the insulating ring above the battery pole group and welded to the bottom of the combined cap .

Next, the support frame is loaded into the middle of the battery pole group.

In this example, the electrolyte may be injected into the battery pack of the battery cartridge before or after the negative/positive terminal is welded to the combined cap.

Preferably, the combined cap comprises a conductive plate connecting the battery pole set, a conductive pressure protection device, a thermistor and a conductive top plate, wherein the combined cap sequentially stacks the conductive plate, the pressure protection device, the thermistor and the top plate through The insulating seals are fastened together from the periphery.

Specifically, the pressure protection device includes an elastic portion that welds the conductive plate and a connecting portion that extends from the elastic portion, and a protective gap is formed at the intersection of the elastic portion and the connecting portion.

The pressure F2 acts on the bent annular wall.

Beneficial effect

The beneficial effects of the present invention compared with the prior art are: 1) a cylindrical battery manufacturing method of the present invention capable of improving battery capacity, using a compression process to thereby height the annular groove and the combined cap on the battery cylinder (h2+ H3) is reduced to (h2+h3)', so that the height h1 of the battery pole group is increased by Δh, which directly increases the expansion area of the battery pole group 13, thereby increasing the battery capacity and making full use of the internal space of the battery; 2) The invention discloses a cylindrical battery manufacturing method capable of improving battery capacity, which can significantly increase battery capacity, such as a 18650-type roll-sealed lithium ion battery, and a cylindrical battery standard height H 65 mm, the height of the battery pole set in the conventional process is 58 mm, the height of the battery pole set in the present invention is 59.5=58+1.5 mm; the height h2 of the annular groove is conventionally 1.7 mm, and the ring shape is adopted by the process of the present invention. The height h2' of the groove is reduced to 0.1 to 0.2 mm. By adopting the process of the invention, the battery cylinder can be selected from a battery cylinder which is more than 1.5 mm higher than the original, and the upper 1.5 mm multi-cell cylinder portion provides an opportunity for the battery pole group to increase the height, thereby increasing the battery pole. The actual use space of the group is achieved by increasing the height of the battery pole group to increase the battery capacity.

DRAWINGS

The present invention will be further described in detail below by way of embodiments with reference to the accompanying drawings:

1 is a cross-sectional view showing a method of manufacturing a cylindrical battery in which a top insulating ring is placed in a battery can;

2 is a cross-sectional view of a cylindrical battery after a roll groove process in a conventional cylindrical battery manufacturing method;

3 is a cross-sectional view of a cylindrical battery in which a support frame is placed in the middle of a pole group in a conventional method of manufacturing a cylindrical battery;

4 is a cross-sectional view showing a conventional cap battery manufacturing method in which a cap is placed on top of a battery can;

Figure 5 is a cross-sectional view showing an integrated composite cap in a conventional cylindrical battery manufacturing method;

6 is a schematic view showing a height distribution of a battery assembly in a conventional method for manufacturing a cylindrical battery;

Figure 7 is a cross-sectional view of a combined cap in a conventional method of manufacturing a cylindrical battery;

Figure 8 is a cross-sectional view showing a combined cap in the method of manufacturing a cylindrical battery of the present invention;

Figure 9 is a cross-sectional view showing the bottom and top insulating rings placed in the battery can in the method of manufacturing a cylindrical battery of the present invention;

Figure 10 is a cross-sectional view showing a cylindrical battery after the roll groove process in the method for manufacturing a cylindrical battery of the present invention;

Figure 11 is a cross-sectional view showing a cylindrical battery in which a support frame is placed in the middle of a pole group in a method of manufacturing a cylindrical battery of the present invention;

Figure 12 is a cross-sectional view showing the assembled cap in the method of manufacturing a cylindrical battery of the present invention;

Figure 13 is a cross-sectional view showing a battery in which a combined cap is applied by applying an external force F1 in the method of manufacturing a cylindrical battery of the present invention.

Figure 14 is a schematic view showing the height distribution of the battery assembly in the method of manufacturing a cylindrical battery of the present invention.

Figure 15 is a cross-sectional view of a battery in which a pressure F2 compression annular groove is applied in a method of manufacturing a cylindrical battery of the present invention.

Figure 16 is a schematic view showing the height distribution of the battery assembly after the annular groove is compressed in the method for manufacturing a cylindrical battery of the present invention.

Embodiments of the invention

The invention will be further described in detail below with reference to specific embodiments and drawings.

The present invention relates to a method of manufacturing a cylindrical battery capable of increasing battery capacity by using a battery electrode group 13 having a height h1 + Δh in a battery can 11 of a cylindrical battery; The open end of the barrel 11 is formed with an annular groove 112 having a height h2; a combined cap 12 having a height h3 is placed over the annular groove 112 in the battery cylinder 11, and the combined cap 12 is connected to the battery electrode group 13, and The combination cap 12 is fixedly sealed to the battery can 11 . In this example, the height of the battery barrel 11 is H + Δh = (h1 + Δh) + h2 + h3, where H is the standard height of the cylindrical battery.

The battery cylinder 11 in this example is closed at the bottom, and the top has an opening for loading the battery assembly. After the components such as the battery electrode group 13 and the combination cap 12 are assembled, a sealing end is formed on the top of the battery. Applying pressure (F2) to the sealing end, applying pressure (F2) from the sealing end of the battery, the pressure (F2) shortening the annular groove and the combined cap of height h2+h3 by Δh, and the height of the annular groove and the combined cap is reduced to (h2+h3)', that is, (h2+h3)'=(h2+h3)-Δh, after compressing the annular groove, the cylindrical battery recovers to the standard height H =(h1+Δh)+ (h2+h3)'=(h1+Δh)+(h2+h3)-Δh. Thereby, the height h1 of the battery pole group 13 is increased by Δh, which directly increases the expanded area of the battery pole group 13, and increases the battery capacity.

The technical solution of the present invention will be specifically described below.

Referring to FIG. 1 to FIG. 16 , the cylindrical battery in the present embodiment mainly includes a battery cylinder 11 , a battery pole set 13 formed by winding in the battery cylinder 11 and having a height h1+Δh, and being mounted on the battery cylinder. 11 is a combination of a cap 12 having a height h3 at the top end and a cylindrical support frame 14 disposed in the middle of the battery pole group 13. In this example, the height of the battery barrel 11 is H + Δh = (h1 + Δh) + h2 + h3, where H is the standard height of the cylindrical battery.

A bottom insulating ring 17 for separating the positive/negative electrode terminal 152 and the battery electrode group 13 is disposed at the bottom of the battery can 11 , and the positive/negative electrode terminal 152 bypasses the bottom insulating ring 17 and the bottom of the battery can 11 contact. The top of the battery barrel 11 is provided with a top insulating ring 16 for insulating the battery electrode group 13 and the combined cap 12 from each other. The top insulating ring 16 is pressed over the battery pole group 13 and is caught under the annular groove 112 formed on the battery cylinder 11. The center of the top insulating ring 16 is provided with a tab hole (not shown) through which the upwardly extending negative/positive terminal 151 can pass, the diameter of which is slightly larger than the diameter of the support frame 14 and can accommodate the negative/positive terminal. 151. The support frame 14 can be placed in the center of the battery pole group 13 from the open end of the battery can 11 through the tab hole.

The battery cylinder 11 forms an annular groove 112 having a height h2 outside the battery cylinder 11 by a roll groove process. In the embodiment, the roller groove process is a rotating roller groove disk arranged in a positive triangle at three positions, and the processed battery cylinder itself also rotates, and the relative movement of the disk and the battery cylinder is outside the battery cylinder. Roll out a uniform ring groove. The annular groove 112 forms a flange for pressing the top insulating ring 16 inside the battery cylinder 11, and the battery cylinder 11 forms an annular wall 111 at the open end above the annular groove 112.

In the present embodiment, the combined cap 12 includes a conductive plate 128 connecting the battery pole group 13, a conductive pressure protection device 124, a thermistor 123, and a conductive top plate 121. The conductive plates 128, the pressure protection device 124, the thermistor 123, and the top plate 121, which are sequentially stacked by the combination cap 12, are fastened together by the insulating seal 122 from the periphery. A plurality of solder joints are disposed at the bottom of the conductive plate 128, and the solder joints are soldered to the negative/positive terminal terminals 151 extending upward from the battery pole group 13. The conductive plate 128 is welded to the pressure protection device 124.

A receiving ring for the fence conductive plate 128 is disposed below the insulating sealing member 122.

In this example, a thermistor 123 is used to connect the pressure protection device 124 and the top plate 121. Lithium-ion cylindrical batteries are superior to other types of rechargeable batteries, such as nickel-cadmium batteries and nickel metal hydride batteries, due to their light weight and high energy density. Lithium-ion batteries are extremely sensitive to overcharging, and safety has always been a concern of battery manufacturers. For example, the battery unit becomes overcharged, and metallic lithium may be plated on the electrode of the battery unit, which causes a fire due to the flammable characteristics of the metallic lithium, and removes the toxic gas when the battery temperature becomes too high. Therefore, the thermistor 123 is required as a safety protection device. When the temperature of the battery rises and overheats, when the temperature is between 80 and 90 degrees Celsius in practice, the resistance of the thermistor 123 rises to cut off the current and prevent a disaster.

In this example, from the perspective of safety, a pressure protection device 124 is further employed, which is a destructive protection device. Generally speaking, the pressure protection device of the battery needs to withstand a certain pressure. When the internal pressure of the battery exceeds the withstand voltage limit of the pressure protection device, the pressure protection device is internally damaged, and the battery is released from pressure to prevent the battery from exploding. The pressure protection device 124 includes an elastic portion 242 that welds the conductive plate 128 and a connecting portion 246 that extends from the elastic portion 242 to the periphery. The protective portion 244 is formed at the intersection of the elastic portion 242 and the connecting portion 246. When the internal pressure of the battery exceeds the withstand voltage limit of the pressure protection device, the protection gap 244 of the pressure protection device from the intersection of the elastic portion 242 and the connecting portion 246 is broken, so that the battery is released from pressure and prevents explosion, but the battery is It is damaged and can no longer be used.

Referring to FIG. 9 to FIG. 16 , a method for manufacturing a cylindrical battery capable of improving battery capacity in the present embodiment is specifically described below, and specifically includes the following steps:

As shown in FIG. 9, a bottom insulating ring 17 is disposed at the bottom of the battery cylinder 11, and a battery pole group 13 having a height h1+Δh is loaded into the battery cylinder 11 of the cylindrical battery; The positive/negative electrode terminal 152 is taken down, and the positive/negative electrode terminal 152 bypasses the insulating ring 17 and comes into contact with the bottom of the battery can 11 . A top insulating ring 16 is mounted on the upper portion of the battery pole group 13. Further, the negative/positive terminal 151 is drawn upward from the battery pole group 13. The negative/positive terminal 151 passes through the top insulating ring 16 above the battery pole set 13 and is welded to the bottom of the combined cap 12, in this example, the negative/positive terminal 151 is soldered through the top insulating ring 16 The bottom of the conductive plate 128 of the combined cap 12.

As shown in FIG. 10, an annular groove 112 having a height h2 is formed by a roll groove process outside the battery cylinder 11. The annular groove 112 forms a flange that presses the top insulating ring 16 inside the battery barrel 11. The battery cylinder 11 forms an annular wall 111 at the open end above the annular groove 112.

As shown in Fig. 11, the support frame 14 is placed in the middle of the battery pole group 13.

In this example, the electrolyte may be injected into the battery electrode group 13 in the battery can 11 before or after the negative/positive terminal 151 is welded to the conductive plate 128 of the combination cap 12.

As shown in FIG. 12, the combined cap 12 of height h3 is placed over the flange in the battery barrel 11. The conductive plates 128 at the bottom end of the combined cap 12 are connected to the battery electrode group 13 through the negative/positive terminal terminals 151.

As shown in FIG. 13 and FIG. 14, the annular wall 111 is bent into the battery cylinder 11 by an external force F1, and the annular wall 111 is in close contact with the top plate 121 of the combined cap 12, thereby fixing the combined cap 12 to the battery can. On body 11. At this time, the total height of the battery is H + Δh = (h1 + Δh) + h2 + h3, where H is the standard height of the cylindrical battery.

As shown in Figures 15 and 16, a pressure (F2) is applied from the sealing end of the battery, the pressure (F2) shortening the annular groove and the combined cap of height (h2+h3) by Δh, the height of the annular groove and the combined cap Drop to (h2+h3)', ie (h2+h3)'=(h2+h3)-Δh, after compressing the annular groove, the cylindrical battery recovers to the standard height H = (h1 + Δh) + (h2+h3)' = (h1 + Δh) + (h2+h3) - Δh. Wherein, the pressure F2 acts on the bent annular wall.

Take the example of a 18650-roller-sealed lithium-ion battery as an example. This model cylindrical battery standard height H 65 mm, the height of the battery pole set in the conventional process is 58 mm, the height of the battery pole set in the present invention is 59.5=58+1.5 mm; the height h2 of the annular groove is conventionally 1.7 mm, and the ring shape is adopted by the process of the present invention. The height h2' of the groove is reduced to 0.1 to 0.2 mm. By adopting the process of the invention, the battery cylinder can be selected from a battery cylinder which is more than 1.5 mm higher than the original, and the upper 1.5 mm multi-cell cylinder portion provides an opportunity for the battery pole group to increase the height, thereby increasing the battery pole. The actual use space of the group is achieved by increasing the height of the battery pole group to increase the battery capacity.

The above is a further detailed description of the present invention in connection with the specific preferred embodiments, and the specific embodiments of the present invention are not limited to the description. It will be apparent to those skilled in the art that the present invention may be made without departing from the spirit and scope of the invention.

Claims

A method of manufacturing a cylindrical battery capable of increasing battery capacity, comprising the steps of:

Adding a height Δh of the battery pole group of height h1 into the battery barrel;

Forming an annular groove of height h2 at an open end of the battery barrel;

Connecting the combined cap of height h3 to the battery pole set and placing it above the annular groove of height h2, and sealing with the battery cylinder;

Applying pressure (F2) compresses the annular groove and the combined cap of a total height of h2+h3 by Δh, so that the height of the battery pole group is increased by Δh without changing the standard height of the battery to increase the battery capacity.
A method of manufacturing a cylindrical battery capable of improving battery capacity according to claim 1, wherein:

After the combined cap is fixedly sealed on the battery cylinder, the total height of the battery is higher than the standard height, and is H + Δh = (h1 + Δh) + h2 + h3, wherein H is the standard height of the cylindrical battery;

The pressure (F2) after the compression of the annular groove and the combined cap, the height of the annular groove and the combined cap is reduced to (h2+h3)' =(h2+h3)-Δh, after compressing the annular groove, the cylindrical battery recovers to the standard height H = (h1 + Δh) + (h2+h3)' = (h1 + Δh) + (h2+h3) - Δh.
The method of manufacturing a cylindrical battery according to claim 2, wherein the battery cylinder forms an annular wall at an open end above the annular groove, and the combined cap is placed over the annular groove of the battery cylinder. The annular wall is bent inward by an external force (F1) that securely seals the combined cap in the battery barrel.
The method of manufacturing a cylindrical battery according to claim 3, wherein before the battery pole assembly is assembled into the battery cylinder, an insulating ring is disposed at the bottom of the battery cylinder, from the battery pole group The positive/negative lead terminals are taken out, and the positive/negative lead terminals bypass the insulating ring and are in contact with the bottom of the battery can.
The method of manufacturing a cylindrical battery according to claim 4, wherein an insulating ring is disposed on an upper portion of the battery pole group, and a negative/positive terminal is drawn upward from the battery pole group, the negative / The positive terminal leads through the insulating ring above the battery pole set and is welded to the bottom of the combined cap.
The method of manufacturing a cylindrical battery according to claim 5, wherein the support frame is placed in the middle of the battery pole group.
A method of manufacturing a cylindrical battery capable of improving battery capacity according to claim 4 or 5, wherein the electrolyte is injected into the battery electrode group in the battery can.
The method of manufacturing a cylindrical battery according to claim 1, wherein the combined cap comprises a conductive plate connecting the battery pole group, a conductive pressure protection device, a thermistor, and a conductive top plate. The conductive plates, the pressure protection device, the thermistor, and the top plate in which the combined caps are sequentially stacked are fastened together by an insulating seal.
A method of manufacturing a cylindrical battery capable of improving battery capacity according to claim 8, wherein said pressure protecting means comprises an elastic portion for welding a conductive plate and a connecting portion extending from the elastic portion, said elastic portion and said connecting portion A protection gap is provided at the junction.
A method of manufacturing a cylindrical battery capable of improving battery capacity according to claim 8, wherein a pressure F2 acts on the bent annular wall.