Battery

Abstract

In order to solve the problems that a liquid injection hole formed in a top cover plate of an existing square battery is small in size, long in liquid injection time and low in production efficiency, the battery comprises a pole core, a cover plate assembly and a metal shell, the pole core is connected with the cover plate assembly, the metal shell comprises a containing part and a storage part, and the containing part is provided with a first containing cavity and a second containing cavity; the first accommodating cavity is used for accommodating a pole core, the second accommodating cavity is arranged at one end of the first accommodating cavity, the second accommodating cavity is communicated with the first accommodating cavity, and the second accommodating cavity is used for accommodating a cover plate assembly; the storage part comprises a storage cavity used for storing electrolyte or gas and a sealing end used for liquid injection, and the storage cavity is arranged on one side of the first containing cavity and communicates with the first containing cavity; a sealing end is arranged on the side, away from the first containing cavity, of the storage cavity. According to the battery provided by the invention, the sealing end is used for liquid injection, the liquid injection port is large, the liquid injection speed is increased, the time of a liquid injection procedure is shortened, and the production efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of energy storage, and in particular relates to a battery. Background Art

[0002] Lithium-ion batteries are usually used as products that provide electric energy and are applied to consumer electronic products such as mobile phones, notebooks, wearables, as well as electric vehicles, drones, energy storage power stations, etc. Highly integrated battery packs can more effectively increase the energy density of the battery cells. The power battery industry tends to directly integrate the battery cells into the required battery packs, which effectively improves space utilization and energy density.

[0003] Although the existing square battery shell is an aluminum shell, the injection hole set on the top cover plate is small in size, the square battery takes a long time to inject liquid, and the production efficiency is low. In the existing polymer soft-pack battery formation process, the side reaction between the electrolyte and the electrode will produce a large amount of gas. In order to ensure the normal production of the battery cell, a part of the aluminum-plastic film will be reserved during the battery cell packaging to store the gas generated during the formation process. This reserved part of the aluminum-plastic film is called the battery cell air bag. During the degas exhaust process of the battery cell, the equipment will puncture the battery cell, and the formed gas will be extracted by the equipment, and then the battery cell will be re-sealed, and finally the air bag will be cut off to obtain the finished battery cell; when the equipment is used to extract the gas generated by the formation, there is a problem that the electrolyte is extracted, affecting the battery performance.

[0004] The design of air bags in polymer soft-pack batteries mainly relies on the practical experience of engineers. The width of the air bags is estimated according to the design capacity of the battery cells, but quantitative design cannot be performed. Insufficient design of the air bags will affect the secondary seal of the battery cells, causing poor sealing, resulting in bloating of the battery cells during use or poor appearance of the battery cells. Summary of the invention

[0005] In order to solve the problems that the injection hole arranged on the top cover plate of the existing square battery is small in size, the injection time is long, and the production efficiency is low, the present invention provides a battery, the metal shell includes a first accommodating cavity and an air bag, the air bag includes a storage cavity and a sealing end, the sealing end is provided for injection, the injection port is large, the injection speed is accelerated, the time of the injection process is shortened, and the production efficiency is improved.

[0006] The present application provides a battery, comprising a pole core, a cover plate assembly and a metal shell, wherein the pole core is connected to the cover plate assembly, and the metal shell comprises a accommodating portion and a storage portion, wherein the accommodating portion is provided with a first accommodating cavity and a second accommodating cavity, wherein the first accommodating cavity is used to accommodate the pole core, and the second accommodating cavity is arranged at one end of the first accommodating cavity, and the second accommodating cavity is communicated with the first accommodating cavity, and the second accommodating cavity is used to accommodate the cover plate assembly; the storage portion comprises a storage cavity for storing electrolyte or gas and a sealing end for liquid injection, wherein the storage cavity is arranged at one side of the first accommodating cavity and is communicated with the first accommodating cavity; and the sealing end is arranged on a side of the storage cavity away from the first accommodating cavity.

[0007] Preferably, the metal shell includes a folded edge and two shell bodies, one of the two shell bodies is provided with a first accommodating groove, a second accommodating groove and a third accommodating groove, the third accommodating groove is provided at the end of the first accommodating groove in the first direction, and the first accommodating groove is communicated with the third accommodating groove; in the second direction, the first accommodating groove and the second accommodating groove are arranged at intervals, and the first direction is perpendicular to the second direction;

[0008] The two shell bodies are folded along the folded edge, the first accommodating groove of one shell body and the other shell body form the first accommodating cavity, the third accommodating groove of one shell body and the other shell body form the second accommodating cavity, and the second accommodating groove of one shell body and the other shell body form the storage cavity.

[0009] Preferably, the volume of the first accommodating chamber is V1, the volume of the storage chamber is V2,

[0010] The range of V1:V2 is 1:(0.05~0.5).

[0011] Preferably, along the direction away from the first accommodating groove, the distance between the side surface of the second accommodating groove close to the first accommodating groove and the other shell body gradually increases.

[0012] Preferably, in the first direction, the length of the first receiving groove is L1, the length of the second receiving groove is L2, L2≤L1, and the range of L2:L1 is (0.1~1.0):1.

[0013] Preferably, the distance between the first accommodating groove and the second accommodating groove is X, the depth of the first accommodating groove is H, and H and X satisfy the following relationship: 0.5H≤X≤3H.

[0014] Preferably, the cover plate assembly comprises a first welding surface and a second welding surface, the first welding surface is a plane structure, and the first welding surface is welded to the other shell body;

[0015] The second welding surface includes two arc surfaces, a plane and two inclined surfaces, and the two inclined surfaces are respectively connected to two ends of the plane through the arc surfaces;

[0016] The second welding surface is welded to the third receiving groove of one of the shell bodies.

[0017] Preferably, the cover plate assembly includes a lead-out piece, an insulating member and a cover plate body, a first through hole is provided in the cover plate body, the insulating member is inserted into the first through hole and extends out of the cover plate body, a second through hole is provided in the insulating member, the lead-out piece is provided in the second through hole and extends out of the insulating member, and the length of the lead-out piece extending out of the insulating member is greater than the length of the insulating member extending out of the cover plate body.

[0018] Preferably, in the second direction, the extension direction of the storage cavity is arranged parallel to the extension direction of the first accommodating cavity;

[0019] Or in the second direction, the extension direction of the storage cavity is perpendicular to the extension direction of the first accommodating cavity;

[0020] An extension portion is further provided at one end of the sealing end away from the storage cavity, and the cross section of the extension portion is a polygon.

[0021] Preferably, an inner insulating film is provided on the inner surface of the metal shell facing the pole core, the inner insulating film is provided between the metal shell and the pole core, and the inner insulating film covers the pole core;

[0022] An outer insulating film is disposed on the outer surface of the metal shell facing away from the pole core, and the outer insulating film covers the outer circumference of the metal shell.

[0023] Beneficial effects:

[0024] Compared with the prior art, the battery provided by this application has the following main effects:

[0025] 1) Compared with the injection through the injection hole, the battery provided in the present application has a sealing end for injection, and the injection hole is large, which speeds up the injection speed, shortens the injection process time, and improves production efficiency.

[0026] 2) The battery provided in the present application is provided with a storage chamber, and liquid injection is directly performed once. The excess electrolyte is directly stored in the storage chamber, and multiple injections are not required, thereby simplifying the injection steps. At the same time, in the subsequent infiltration process, the electrolyte in the storage chamber can gradually flow into the first receiving chamber so that the electrolyte in the storage chamber can completely infiltrate the pole core.

[0027] 3) The storage chamber can collect the gas generated by the battery during the formation process, eliminating the need for continuous vacuum exhaust during the formation process, thus saving costs.

[0028] 4) Compared with soft-pack batteries, the battery provided in the present application has a storage cavity for storing electrolyte and gas generated by battery formation, thereby avoiding battery cell bloating or poor appearance caused by insufficient storage. After the formation is completed, the storage cavity is directly flattened to discharge the gas from the battery without vacuum exhaust, thereby reducing the extraction of electrolyte. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram of the structure of a battery (including an extension portion) provided in one embodiment of the present application;

[0030] Figure 2 This is a schematic diagram of the structure of a battery (excluding the extension portion) provided in one embodiment of the present application;

[0031] Figure 3 This is a schematic diagram of an explosion of a battery (excluding an extension portion) provided in one embodiment of the present application;

[0032] Figure 4 This is a schematic diagram of a battery structure (the storage portion is perpendicular to the first accommodating cavity) provided in one embodiment of the present application;

[0033] Figure 5 This is a schematic diagram of the side structure of a battery (the storage cavity is not flattened) provided in one embodiment of the present application;

[0034] Figure 6 This is a schematic diagram of the side structure of a battery (storage cavity is flattened) provided by an embodiment of the present application;

[0035] Figure 7 This is a cross-sectional view of a battery provided by an embodiment of the present application;

[0036] Figure 8 yes Figure 7 Enlarged view of part A.

[0037] Fig. 9 This is a schematic diagram of the structure of a cover assembly provided in one embodiment of the present application.

[0038] Among them, 100, battery; 1, pole core; 2, metal shell; 21, first shell body; 22, second shell body; 211, first accommodating groove; 212, third accommodating groove; 213, storage part; 2131, second accommodating groove; 2132, sealing end; 2133, extension part; 3, cover assembly; 31, lead-out piece; 32, insulating member; 33, cover body; 34, first welding surface; 35, second welding surface; 351, plane; 352, inclined surface; 353, arc surface; 4, inner insulating film; 5, outer insulating film. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0040] In order to illustrate the technical solution of the present invention, specific embodiments are provided below for illustration.

[0041] like Figure 1-Figure 9 An embodiment of the present application provides a battery 100, comprising a pole core 1, a cover plate assembly 3 and a metal shell 2, wherein the pole core 1 is connected to the cover plate assembly 3, the metal shell 2 comprises a accommodating portion and a storage portion 213, the accommodating portion is provided with a first accommodating cavity and a second accommodating cavity, the first accommodating cavity is used to accommodate the pole core 1, the second accommodating cavity is arranged at one end of the first accommodating cavity, and the second accommodating cavity is communicated with the first accommodating cavity, the second accommodating cavity is used to accommodate the cover plate assembly 3, the storage portion 213 comprises a storage cavity for storing electrolyte or gas and a sealing end 2132 for liquid injection, the storage cavity is arranged at one side of the first accommodating cavity, and is communicated with the first accommodating cavity; the sealing end 2132 is provided on the side of the storage cavity away from the first accommodating cavity.

[0042] Specifically, Figure 1-3 As shown, the battery 100 provided in the present application includes two cover plate assemblies 3, one of which is a positive cover plate assembly and the other is a negative cover plate assembly. The positive cover plate assembly is welded to the positive pole ear of the pole core 1, and the negative cover plate assembly is welded to the negative pole ear of the pole core 1. It should be noted that the first direction and the second direction of the present application are, for example, Figure 1 As shown, the first direction is the x direction, the second direction is the y direction, and the first direction is perpendicular to the second direction.

[0043] like Figure 1-2As shown, the pole core 1 is connected to the cover plate assembly 3, preferably the pole core 1 and the cover plate assembly 3 are connected by welding, and the welding method can be laser welding. In the first direction, a second accommodating cavity is provided at each end of the first accommodating cavity, and each second accommodating cavity accommodates a cover plate assembly 3. The first accommodating cavity in the metal shell 2 is used to accommodate the pole core 1, and the second accommodating cavity is connected to the first accommodating cavity, so that the second accommodating cavity can be used to accommodate the cover plate assembly 3.

[0044] The storage part 213 includes a storage cavity and a sealing end 2132. The storage cavity is disposed at one end of the first accommodating cavity in the second direction, and the sealing end 2132 is disposed at a side of the storage cavity away from the first accommodating cavity. The storage cavity is used to store electrolyte or gas. Figure 1-2 As shown, the storage cavity is mainly used to store electrolyte or gas. The gas here refers to the gas generated during the charging and discharging process of the battery 100. The electrolyte is stored because the battery 100 provided in the present application is injected once, and the pole core 1 cannot completely absorb the electrolyte. Excess electrolyte may be stored in the storage cavity. As the static time of the battery 100 increases, the electrolyte in the storage cavity can flow into the first receiving cavity, so that the electrolyte can be absorbed by the pole core 1. Before the battery 100 is injected with liquid, the sealing end 2132 is an open end before the battery 100 is sealed, and except for the shell at the open end which is not sealed, the other two sides of the battery 100 have been sealed and welded. When the battery 100 is injected with liquid, the open end is directly opened, the injection end in the injection device is aligned with the open end, and the electrolyte is injected into the battery 100 through the open end. Injecting the electrolyte through the open end can make the electrolyte quickly infiltrate the pole core 1, thereby improving the infiltration efficiency of the electrolyte. After the injection is completed, the open end is sealed and welded to form the sealing end 2132. The sealing method can be selected from laser welding or resistance welding.

[0045] Compared with the prior art, the battery 100 provided in this application has the following main effects:

[0046] 1) Compared with injecting liquid through an injection hole, the battery 100 provided in the present application is provided with a sealing end 2132 for injecting liquid, and the injection hole is large, which speeds up the injection speed, shortens the injection process time, and improves production efficiency.

[0047] 2) Compared with the existing battery 100, the battery 100 provided in the present application is provided with a storage chamber, and liquid injection is directly performed once. The excess electrolyte is directly stored in the storage chamber, and multiple injections are not required, thereby simplifying the injection steps; at the same time, in the subsequent infiltration process, the electrolyte in the storage chamber can gradually flow into the first receiving chamber so that the electrolyte in the storage chamber can completely infiltrate the pole core 1.

[0048] 3) The storage chamber can collect the gas generated by the battery 100 during the formation process, eliminating the need for continuous vacuum exhaust during the formation process, thus saving costs.

[0049] 4) Compared with the soft-pack battery 100, the battery 100 provided in the present application has a storage cavity for storing electrolyte and gas generated by the formation of the battery 100, so as to avoid the problem of battery cell bloating or poor appearance caused by insufficient storage part 213; after the formation is completed, the storage cavity is directly flattened to discharge the gas from the battery 100, without the need for vacuum exhaust, thereby reducing the extraction of electrolyte. In some embodiments, the metal shell 2 includes a folded edge and two shell bodies, one of the two shell bodies is provided with a first receiving groove 211, a second receiving groove 2131 and a third receiving groove 212, and the third receiving groove 212 is provided at the end of the first receiving groove 211 in the first direction, and the first receiving groove 211 is connected to the third receiving groove 212; in the second direction, the first receiving groove 211 and the second receiving groove 2131 are spaced apart, and the first direction is perpendicular to the second direction;

[0050] The two shell bodies are folded along the folded edge, the first accommodating groove 211 of one shell body and the other shell body form the first accommodating cavity, the third accommodating groove 212 of one shell body and the other shell body form the second accommodating cavity, and the second accommodating groove 2131 of one shell body and the other shell body form the storage cavity.

[0051] Specifically, the two shell bodies are defined as a first shell body 21 and a second shell body 22. The first shell body 21 is provided with a first receiving groove 211, a second receiving groove 2131, and a third receiving groove 212, wherein the first receiving groove 211, the second receiving groove 2131, and the third receiving groove 212 are preferably formed by stamping. The first receiving groove 211 is directly formed on the first shell body 21, and no holes are punched on the second shell body 22. Compared with the existing method of punching holes on both sides of the aluminum-plastic film in soft-pack batteries, the battery 100 provided in the present application reduces the number of steps and shortens the process time. Figure 1-2 As shown, the third accommodating groove 212, the first accommodating groove 211, and the second accommodating groove 2131 are all stamped on the same shell body. The material of the metal shell 2 is preferably aluminum shell material, with uniform wall thickness and consistent overall structural strength. At the same time, the structural strength of the four corners can also be ensured to be consistent. Compared with the existing soft-pack aluminum-plastic film composite film material, the battery 100 provided in the present application uses a metal material for the shell to achieve better heat dissipation effect.

[0052] In some embodiments, the material of the metal shell 2 includes aluminum, aluminum alloy, etc.

[0053] In some embodiments, the thickness of the metal shell 2 is 0.2 mm.

[0054] The second receiving groove 2131 and the second shell body 22 form a storage cavity for storing electrolyte and gas generated by the battery 100. The third receiving groove 212 and the second shell body 22 form a second receiving cavity for accommodating the cover plate assembly 3.

[0055] In some embodiments, the volume of the first accommodating cavity is V1, the volume of the storage cavity is V2,

[0056] The range of V1:V2 is 1:(0.05~0.5). The storage cavity in the battery 100 is used as a liquid storage bag in the liquid injection process of the battery 100 processing, and can be used to store the electrolyte required for the infiltration of the pole core 1 in the first accommodating cavity. During the infiltration process of the pole core 1, the electrolyte stored in the storage cavity will gradually penetrate into the first accommodating cavity. In addition, the storage cavity is used as an exhaust bag in the formation process of the battery 100 processing, and can be used to store the gas generated by the formation of the battery 100. After the formation process is completed, the storage cavity can be separated from the first accommodating cavity by cutting, or the storage cavity can be flattened by exhausting gas, so that the battery 100 forms heat dissipation fins at the storage cavity. Therefore, under the premise of meeting the processing requirements of the pole core 1 in the first accommodating cavity, the volume of the storage cavity is as small as possible.

[0057] Specifically, Figure 1-3 As shown, the height of the storage cavity is less than the height of the first accommodating cavity, and the volume V2 of the storage cavity is limited to be less than the volume V1 of the first accommodating cavity. At the same time, the range of V1:V2 is limited to 1:(0.05-0.5), which can not increase the overall thickness of the battery 100, reduce the occupied volume of the storage cavity, and also have a storage cavity with sufficient volume to store the gas generated by the formation of the battery 100, thereby avoiding or reducing the occurrence of bloating of the battery 100. At the same time, due to the different processing techniques of the battery 100, the exhaust volume of the pole core 1 will also vary greatly. Therefore, under the premise of the same volume V1 of the first accommodating cavity, according to different processing techniques, the volume V2 of the storage cavity can be adjusted so that the volume V2 of the storage cavity can meet the processing requirements of the battery 100.

[0058] More preferably, the range of V1:V2 is 1:(0.1-0.4). More preferably, the range of V1:V2 is 1:(0.1-0.3); More preferably, the range of V1:V2 is 1:(0.1-0.2).

[0059] In some preferred embodiments, the ratio of V1:V2 is 1:0.166. The volume V1 of the first accommodating chamber is related to the volume V2 of the storage chamber. The larger the volume V1 of the first accommodating chamber, the larger the volume V2 of the storage chamber. Generally speaking, the volume V1 of the first accommodating chamber is 6 times the volume V2 of the storage chamber, which can meet the exhaust and injection requirements of the pole core 1 inside the first accommodating chamber during the processing, that is, the ratio of the volume V1 of the first accommodating chamber to the volume V2 of the storage chamber is 1:0.166.

[0060] In some embodiments, along the direction away from the first receiving groove 211 , the distance between the side surface of the second receiving groove 2131 close to the first receiving groove 211 and the other shell body gradually increases.

[0061] Specifically, Figure 1 As shown, along the direction away from the first receiving groove 211, that is, along the direction of the y-axis, the side of the second receiving groove 2131 close to the first receiving groove 211 is inclined, and the inclination direction is from the bottom of the second receiving groove 2131 to the direction close to the second shell body 22, and the distance between the side of the first receiving groove 211 and the second shell body 22 gradually increases. The second receiving groove 2131 is inclined on the side close to the first receiving groove 211 to facilitate the electrolyte to flow into the first receiving cavity along the inclined side; at the same time, when the battery 100 is exhausted after formation, it is convenient to exhaust the gas in the storage cavity along the inclined side, and there is no need to evacuate the gas, thereby reducing the electrolyte from being extracted.

[0062] In some embodiments, in the first direction, the length of the first receiving groove 211 is L1, the length of the second receiving groove 2131 is L2, L2≤L1, and the range of L2:L1 is (0.1~1.0):1.

[0063] Specifically, in the first direction, the length L1 of the first accommodating groove 211 is greater than or equal to the length L2 of the second accommodating groove 2131, and the range of L2:L1 is (0.1~1.0):1, that is, the length of the second accommodating groove 2131 is less than the length of the pole core 1, which does not increase the overall length of the battery 100 and reduces the occupied volume of the storage cavity.

[0064] Specifically, the ratio of L2:L1 can be 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 or 1.0, etc., as long as the ratio of L2:L1 is within the range of (0.1-1.0):1. Figure 1 As shown, the length L2 of the second receiving groove 2131 is equal to the length L1 of the first receiving groove 211 , that is, L1 = L2.

[0065] In some embodiments, the cover plate assembly 3 includes a first welding surface 34 and a second welding surface 35, the first welding surface 34 is a plane 351 structure, and the first welding surface 34 is welded to another shell body;

[0066] The second welding surface 35 includes two arc surfaces 353, a plane 351 and two inclined surfaces 352, and the two inclined surfaces 352 are connected to two ends of the plane 351 through the arc surfaces 353 respectively;

[0067] The second welding surface 35 is welded to the third receiving groove 212 of a shell body.

[0068] Specifically, the first welding surface 34 is set as a plane 351 structure to facilitate welding the first welding surface 34 and the second shell body 22, reduce welding difficulty, and improve welding efficiency; the welding method here includes laser welding or resistance welding, and laser welding is preferred.

[0069] The second welding surface 35 is composed of an arc surface 353, a plane 351 and an inclined surface 352. This is because the cover assembly 3 has a certain thickness, so a third receiving groove 212 is provided on the first shell body 21 to accommodate the cover assembly 3 with a certain thickness; the shape of the third receiving groove 212 is the same as the shape of the second welding surface 35 in the cover assembly 3, so as to facilitate accommodating the cover assembly 3. Fig. 9 As shown, the second welding surface 35 includes a plane 351, and an arc surface 353 is provided at each end of the plane 351. The arc surface 353 plays a transition role. The end of each arc surface 353 away from the plane 351 is connected to a slope 352, and the slope 352 plays a role in facilitating the sealing welding of the second shell body 22 and the first shell body 21. If there is no transition of the slope 352, there will be gaps in the welding between the cover plate assembly 3 and the first shell body 21 and the second shell body 22, which affects the sealing of the battery 100.

[0070] In some embodiments, the cover assembly 3 includes a lead-out piece 31, an insulating member 32 and a cover body 33, the cover body 33 is provided with a first through hole, the insulating member 32 is inserted into the first through hole and extends out of the cover body 33, a second through hole is provided in the insulating member 32, the lead-out piece 31 is provided in the second through hole and extends out of the insulating member 32, and the length of the lead-out piece 31 extending out of the insulating member 32 is greater than the length of the insulating member 32 extending out of the cover body 33.

[0071] The insulating member 32 extends out of the cover body 33 to provide insulation to prevent short circuit of the battery 100. The lead-out piece 31 extends out of the insulating member 32, with one end of the extension being welded to the pole ear or connecting piece of the pole core 1, and the other end of the extension being used to electrically connect to an external circuit.

[0072] Furthermore, the length of the lead-out piece 31 extending out of the insulating member 32 is greater than the length of the insulating member 32 extending out of the cover body 33, which is 6-7 mm; it is convenient for one end of the lead-out piece 31 to be welded to the pole ear or connecting piece of the pole core 1, and the other end of the lead-out piece 31 is used to be electrically connected to the external circuit. The cover assembly 3 in this embodiment has no injection hole, and the pole is the lead-out piece 31, which can be as thin as 0.5 mm. Therefore, the thickness of the cover assembly 3 can be extremely thin, and the overall thickness of the corresponding battery 100 can also be extremely thin (the thinnest can be 6 mm thick). The existing battery 100 is limited by the structure of the cover assembly 3, and generally 18 mm is very thin (because the cover assembly 3 of the existing square battery 100 includes a pole, an injection hole, an explosion-proof valve, etc., and the width of the cover assembly 3 is relatively wide), so compared with the prior art, the battery 100 provided in this application is thinner, reducing the occupied space of the battery 100.

[0073] In some embodiments, in the second direction, the extension direction of the storage cavity is parallel to the extension direction of the first accommodating cavity; or in the second direction, the extension direction of the storage cavity is perpendicular to the extension direction of the first accommodating cavity.

[0074] A configuration of the storage chamber and the first receiving chamber is as follows: Figure 1-2 As shown, in the second direction, the storage cavity and the first accommodating cavity are arranged side by side, and the extension direction of the storage cavity is arranged parallel to the extension direction of the first accommodating cavity.

[0075] Another arrangement of the storage chamber and the first accommodation chamber is as follows Figure 4 As shown, the extension direction of the storage cavity is perpendicular to the extension direction of the first accommodating cavity.

[0076] It can be understood that the extension direction of the storage cavity and the extension direction of the first accommodating cavity have an angle, and the angle can be in the range of 0-180°. For an angle of 0 or 180°, it is a parallel arrangement, and an angle of 90° is a vertical arrangement. Other angles are also possible. When the angle is an acute angle, the inclined surface is more conducive to the diversion of the electrolyte in the storage cavity.

[0077] In some embodiments, an inner insulating film 4 is provided on the inner surface of the metal shell 2 facing the pole core 1, the inner insulating film 4 is provided between the metal shell 2 and the pole core 1, and the inner insulating film 4 covers the pole core 1;

[0078] An outer insulating film 5 is provided on the outer surface of the metal shell 2 facing away from the pole core 1 , and the outer insulating film 5 covers the outer circumference of the metal shell 2 .

[0079] The inner insulating film 4 covers the pole core 1 , and the outer insulating film 5 covers the outer periphery of the metal shell 2 , both of which prevent the battery 100 from short circuiting.

[0080] It is understandable that the structure of the inner insulating film 4 is the same as that of the metal shell 2. The structure of the inner insulating film 4 may also be different from that of the metal shell 2, as long as the inner insulating film 4 is coated on the outer periphery of the pole core 1 to prevent the battery 100 from short circuiting. Figure 3 As shown, the structure of the outer insulating film 5 is preferably the same as that of the metal shell 2, so that the outer insulating film 5 can be completely covered on the periphery of the metal shell 2 to prevent the battery 100 from short circuiting.

[0081] In some embodiments, Figure 1-2 As shown, the side surface of the first accommodating groove 211 close to the second accommodating groove 2131 is an arc surface, and the side surface of the second accommodating groove 2131 close to the first accommodating groove 211 is also an arc surface.

[0082] The first receiving groove 211 and the second receiving groove 2131 are both formed by punching. The side of the first receiving groove 211 close to the second receiving groove 2131 is punched into an arc surface, and the side of the second receiving groove 2131 close to the first receiving groove 211 is also an arc surface, which can reduce material stress and effectively improve the punching efficiency of the first receiving groove 211 and the second receiving groove 2131.

[0083] In some embodiments, the distance between the first receiving groove 211 and the second receiving groove 2131 is X, the depth of the first receiving groove 211 is H, and H and X satisfy the following relationship: 0.5H≤X≤3H.

[0084] If X is too low, the distance between the first receiving groove 211 and the second receiving groove 2131 is too close, and the first receiving groove 211 and / or the second receiving groove 2131 are easily broken during punching, which increases the production cost. If X is too large, the volume of the metal shell 2 increases, the cost of the battery 100 increases, and the volume energy density decreases. The distance X between the first receiving groove 211 and the second receiving groove 2131 and the depth H of the first receiving groove 211 satisfy the following relationship: 0.5H≤X≤3H, which can effectively improve the efficiency of punching to form the first receiving groove 211 and the second receiving groove 2131.

[0085] It should be noted that the first accommodating groove 211 is close to the first side surface of the second accommodating groove 2131, and the second accommodating groove 2131 is close to the second side surface of the first accommodating groove 211, and both the first side surface and the second side surface are arc surfaces. The distance X between the first accommodating groove 211 and the second accommodating groove 2131 defined in this embodiment is the distance between the side of the first side surface opening toward the first accommodating groove 211 and the side of the second side surface opening toward the second accommodating groove 2131.

[0086] In some preferred embodiments, H and X satisfy the following relationship: 1.0H≤X≤2.5H.

[0087] More preferably, H and X satisfy the following relationship: 1.0H≤X≤2.0H; and even more preferably, X=1.5H.

[0088] In some embodiments, an extension portion 2133 is further provided at one end of the sealing end 2132 away from the storage cavity, and the cross-section of the extension portion 2133 is polygonal.

[0089] like Figure 1 As shown, the extension part 2133 can also be used to store gas. When the battery 100 is formed, the extension part 2133 stores gas. The extension part 2133 is directly cut to release the gas in the storage cavity and the extension part 2133. Then, the cut part is welded to seal the battery 100. The welding method can be laser welding or resistance welding, preferably resistance welding. Figure 2 As shown, or the extension portion 2133 is cut off, the cross section of the sealing end 2132 is a straight line, and the trimmed portion of the metal shell 2 is directly welded by resistance welding or laser welding.

[0090] It should be noted that the cross section of the extension portion 2133 is a polygon, the number of sides of the polygon is n, n≥3, such as a square, a rectangle, a pentagon, etc., and the cross section is preferably a square or a rectangle.

[0091] In some embodiments, the cross-section of the sealing end 2132 is linear or L-shaped.

[0092] like Figure 2 As shown, when the extension part 2133 is cut off as a whole, the cross section of the sealing end 2132 is a straight line, and if the extension part 2133 is not cut off, the cross section of the sealing end 2132 is an L shape. Whether to cut off the extension part 2133 can be selected according to actual needs, and this application does not limit it.

[0093] It should be noted that the gas generated after the battery 100 is formed can be discharged from the battery 100 by flattening the storage cavity. Because there is electrolyte in the storage cavity, if the storage cavity is directly cut off and the metal shell 2 is sealed and welded, the presence of electrolyte will affect the welding of the shell. Therefore, the battery 100 provided in this application retains the storage cavity. The battery 100 retaining the storage cavity can improve the welding efficiency of the two bending surfaces and improve production efficiency. Figure 5 , 6 It can be seen that Figure 5 This is a structural diagram without flattening the storage cavity. Figure 6 This is a structural diagram of directly flattening the storage cavity after exhausting the gas. It is understandable that whether the storage cavity is flattened can be selected according to the actual situation, and this application does not limit it.

[0094] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. Although the present invention has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that the technical solutions described in the above embodiments can still be modified, or some of the technical features can be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention.

Claims

1. A battery, It is characterized in that It includes a pole core, a cover plate assembly and a metal shell, the pole core is connected to the cover plate assembly, the metal shell includes a accommodating part and a storage part, the accommodating part is provided with a first accommodating cavity and a second accommodating cavity, the first accommodating cavity is used to accommodate the pole core, the second accommodating cavity is arranged at one end of the first accommodating cavity, and the second accommodating cavity is communicated with the first accommodating cavity, and the second accommodating cavity is used to accommodate the cover plate assembly; the storage part includes a storage cavity for storing electrolyte or gas and a sealing end for liquid injection, the storage cavity is arranged at one side of the first accommodating cavity, and is communicated with the first accommodating cavity; the sealing end is provided on the side of the storage cavity away from the first accommodating cavity.

2. The battery according to claim 1, It is characterized in that The metal shell comprises a folded edge and two shell bodies, one of the two shell bodies is provided with a first receiving groove, a second receiving groove and a third receiving groove, the third receiving groove is provided at the end of the first receiving groove in the first direction, and the first receiving groove is communicated with the third receiving groove; the first receiving groove and the second receiving groove are arranged at intervals in the second direction, and the first direction is perpendicular to the second direction; The two shell bodies are folded along the folded edge, the first accommodating groove of one shell body and the other shell body form the first accommodating cavity, the third accommodating groove of one shell body and the other shell body form the second accommodating cavity, and the second accommodating groove of one shell body and the other shell body form the storage cavity.

3. The battery according to claim 1 or 2, It is characterized in that The volume of the first accommodating chamber is V1, the volume of the storage chamber is V2, The range of V1:V2 is 1:(0.05~0.5).

4. The battery according to claim 2, It is characterized in that Along the direction away from the first accommodating groove, the distance between the side surface of the second accommodating groove close to the first accommodating groove and the other shell body gradually increases.

5. The battery according to claim 2, It is characterized in that In the first direction, the length of the first receiving groove is L1, the length of the second receiving groove is L2, L2≤L1, and the range of L2:L1 is (0.1~1.0):

1.

6. The battery according to claim 5, It is characterized in that The distance between the first accommodating groove and the second accommodating groove is X, the depth of the first accommodating groove is H, and H and X satisfy the following relationship: 0.5H≤X≤3H.

7. The battery according to claim 2, It is characterized in that The cover plate assembly comprises a first welding surface and a second welding surface, the first welding surface is a plane structure, and the first welding surface is welded to the other shell body; The second welding surface includes two arc surfaces, a plane and two inclined surfaces, and the two inclined surfaces are respectively connected to two ends of the plane through the arc surfaces; The second welding surface is welded to the third receiving groove of one of the shell bodies.

8. The battery according to claim 1, It is characterized in that The cover assembly includes a lead-out piece, an insulating member and a cover body, wherein a first through hole is provided in the cover body, the insulating member is inserted into the first through hole and extends out of the cover body, a second through hole is provided in the insulating member, the lead-out piece is provided in the second through hole and extends out of the insulating member, and the length of the lead-out piece extending out of the insulating member is greater than the length of the insulating member extending out of the cover body.

9. The battery according to claim 1, It is characterized in that In the second direction, the extension direction of the storage cavity is arranged parallel to the extension direction of the first accommodating cavity; Or in the second direction, the extension direction of the storage cavity is perpendicular to the extension direction of the first accommodating cavity; An extension portion is further provided at one end of the sealing end away from the storage cavity, and the cross section of the extension portion is a polygon.

10. The battery according to claim 1, It is characterized in that An inner insulating film is provided on the inner surface of the metal shell facing the pole core, the inner insulating film is provided between the metal shell and the pole core, and the inner insulating film covers the pole core; An outer insulating film is disposed on the outer surface of the metal shell facing away from the pole core, and the outer insulating film covers the outer circumference of the metal shell.

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