Square battery structure

Abstract

According to the square battery structure, in the structure, a shell is of a square open structure, a core bag is contained in the shell, the core bag comprises a negative electrode lug and a positive electrode lug, a negative electrode connecting piece is connected with the negative electrode lug, a positive electrode connecting piece is connected with the positive electrode lug, a top cover covers an opening of the shell, and a cover plate and a lower plastic layer stacked below the cover plate cover the opening; the negative column is arranged on the cover plate and connected with the negative connecting piece, the positive column is arranged on the cover plate and connected with the positive connecting piece, the top cover liquid injection hole penetrates through the cover plate, the lower plastic layer corresponds to the hollow part at the top cover liquid injection hole, and the support is located at the hollow part and comprises a plurality of pins connected with the inner top wall of the cover plate and a baffle connected with the pins. According to the structure, enough exhaust space is reserved, the fire and explosion risk caused by unsmooth exhaust due to thermal runaway of the battery is avoided, the pressure during electrolyte injection is relieved, and the short circuit risk caused by lap joint of the positive electrode and the negative electrode due to the fact that the diaphragm is collapsed by the electrolyte with pressure is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium-ion batteries, in particular to a square battery structure. Background Art

[0002] With the rapid growth of lithium-ion battery applications in the power and energy storage sectors, the industry's safety requirements for lithium batteries are becoming increasingly stringent. In order to avoid safety risks caused by thermal runaway of battery cells, an explosion-proof valve exhaust structure is generally designed on the top cover of the battery; however, when thermal runaway occurs in a high-energy-density battery, after the explosion-proof valve is opened, the high-temperature and high-pressure gas instantly generated inside the battery will squeeze the positive and negative electrodes toward the explosion-proof valve port, causing the explosion-proof valve port to be blocked and unable to continuously discharge the high-temperature and high-pressure gas generated inside the battery, increasing the risk of fire and explosion of the battery. The existing technology is provided with an insulating lower plastic, and the lower plastic boss structure can press the electrode and the diaphragm to ensure that there is sufficient exhaust space between the electrode and the explosion-proof valve port; however, when thermal runaway occurs in a high-energy-density battery, the high-temperature and high-pressure gas inside will instantly melt the lower plastic, and the electrode will be squeezed to the explosion-proof valve port by the high-pressure gas, resulting in poor exhaust and the risk of fire and explosion of the battery.

[0003] The above information disclosed in the background technology section is only used to enhance understanding of the background of the present invention and therefore may contain information that does not constitute the prior art known to ordinary technicians in this field. Utility Model Content

[0004] The utility model aims to provide a square battery structure, which can ensure sufficient exhaust space inside the battery when thermal runaway occurs in the battery cell, so as to avoid the pole piece blocking the exhaust port of the explosion-proof valve.

[0005] In order to achieve the above purpose, the present invention provides the following technical solutions:

[0006] A square battery structure of the utility model includes:

[0007] The shell is a square open structure.

[0008] A core pack is contained in the shell, and includes a negative electrode tab and a positive electrode tab.

[0009] A negative electrode connecting piece, which is connected to the negative electrode tab,

[0010] A positive electrode connecting piece, which is connected to the positive electrode tab,

[0011] A top cover is provided on the opening of the housing, and the top cover includes:

[0012] The cover plate and the lower plastic layer stacked thereunder cover the opening.

[0013] A negative electrode column, which is provided on the cover plate and connected to the negative electrode connecting piece,

[0014] A positive electrode column, which is provided on the cover plate and connected to the positive electrode connecting piece,

[0015] The top cover liquid injection hole is provided through the cover plate and the lower plastic layer is hollowed out corresponding to the top cover liquid injection hole.

[0016] A bracket is located in the hollow part, and the bracket includes a plurality of pins connected to the inner top wall of the cover plate and a baffle connected to the pins.

[0017] In the square battery structure, the cover plate is further provided with an explosion-proof valve, and the lower plastic layer is provided with a grid away from the cover plate at a position corresponding to the explosion-proof valve.

[0018] In the square battery structure, the explosion-proof valve is provided with an explosion-proof valve protective film.

[0019] In the square battery structure, a pair of brackets are symmetrically distributed on both sides of the explosion-proof valve.

[0020] In the square battery structure, the negative electrode connecting piece includes wings connected to the negative electrode tab and a head connected to the negative electrode column.

[0021] In the square battery structure, the positive electrode connecting piece includes wings connected to the positive electrode tab and a head connected to the positive electrode column.

[0022] In the square battery structure, the lower plastic layer is provided with bosses at both ends of the side away from the cover plate.

[0023] In the square battery structure, a high-temperature insulating tape layer is affixed to the side of the baffle away from the pins.

[0024] In the square battery structure, the core package includes a stacked separator, a positive electrode sheet and a negative electrode sheet.

[0025] In the square battery structure, the insulating sheet is arranged between the core package and the inner wall of the shell.

[0026] In the above technical solution, the utility model provides a square battery structure with the following beneficial effects: the square battery structure can restrain the movement of the pole pieces in the core package, retain sufficient exhaust space, and avoid the risk of fire and explosion caused by poor exhaust due to thermal runaway of the battery; the bracket structure can reduce the pressure during electrolyte injection, and avoid the diaphragm being collapsed by the pressurized electrolyte, causing the risk of short circuit between the positive and negative poles. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0028] Figure 1 This is an exploded diagram of the battery structure of the present utility model.

[0029] Figure 2 This is a schematic diagram of the explosion of the top cover of the present utility model.

[0030] Figure 3 It is a cross-sectional schematic diagram of the present utility model.

[0031] Figure 4 for Figure 3 Schematic diagram of the cross-section at BB.

[0032] Figure 5 for Figure 3 Schematic diagram of the cross-section at CC.

[0033] Figure 6 for Figure 5 Schematic diagram of the cross-section at DD.

[0034] Figure 7 Schematic diagram of the internal structure of the battery.

[0035] Figure 8 This is a structural diagram of one scheme of this bracket.

[0036] Figure 9 This is a structural diagram of another solution of this bracket.

[0037] Figure 10 This is a schematic diagram of the three-dimensional structure of another solution of this bracket.

[0038] The reference numerals in the figure are as follows: 1. top cover; 2. positive electrode connecting piece; 3. positive electrode tab; 4. shell; 5. insulating sheet; 6. core package; 7. negative electrode tab; 8. negative electrode connecting piece; 9. positive electrode column; 10. cover plate; 11. lower plastic layer; 12. negative electrode column; 13. bracket; 14. explosion-proof valve; 15. explosion-proof valve protective film; 16. baffle; 17. pin; 18. high-temperature insulating tape layer. DETAILED DESCRIPTION

[0039] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0040] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but rather merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0041] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0042] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0043] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of this utility model, "plurality" means two or more, unless otherwise specifically defined.

[0044] In this utility model, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; they can refer to direct connection or indirect connection through an intermediate medium; they can refer to internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on specific circumstances.

[0045] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0046] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0047] like Figure 1-10 As shown, in one embodiment, a square battery structure of the present invention includes:

[0048] The shell 4 is a square open structure.

[0049] The core pack 6 is contained in the shell 4 and includes a negative electrode tab 7 and a positive electrode tab 3.

[0050] The negative electrode connecting piece 8 is connected to the negative electrode tab 7.

[0051] The positive electrode connecting piece 2 is connected to the positive electrode tab 3.

[0052] The top cover 1 is provided on the opening of the housing 4 and includes:

[0053] The cover plate 10 and the lower plastic layer 11 stacked thereunder cover the opening.

[0054] The negative electrode column 12 is provided on the cover plate 10 and connected to the negative electrode connecting piece 8.

[0055] The positive electrode column 9 is provided on the cover plate 10 and connected to the positive electrode connecting piece 2.

[0056] The top cover liquid injection hole is provided through the cover plate 10 and the lower plastic layer 11 is hollowed out corresponding to the top cover liquid injection hole.

[0057] The bracket 13 is located in the hollow portion. The bracket 13 includes a plurality of pins 17 connected to the inner top wall of the cover plate 10 and a baffle 16 connected to the pins 17 .

[0058] In a preferred embodiment of the square battery structure, the cover plate 10 is further provided with an explosion-proof valve 14 , and the lower plastic layer 11 is provided with a grid away from the cover plate 10 at a position corresponding to the explosion-proof valve 14 .

[0059] In a preferred embodiment of the square battery structure, the explosion-proof valve 14 is provided with an explosion-proof valve protection membrane 15 .

[0060] In the preferred embodiment of the square battery structure, a pair of brackets 13 are symmetrically distributed on both sides of the explosion-proof valve 14.

[0061] In a preferred embodiment of the square battery structure, the negative electrode connecting piece 8 includes wings connected to the negative electrode tab 7 and a head connected to the negative electrode column 12 .

[0062] In a preferred embodiment of the square battery structure, the positive electrode connecting piece 2 includes wings connected to the positive electrode tab 3 and a head connected to the positive electrode column 9.

[0063] In a preferred embodiment of the square battery structure, the lower plastic layer 11 is provided with bosses at both ends of the side away from the cover plate 10 .

[0064] In a preferred embodiment of the square battery structure, a high-temperature insulating tape layer 18 is attached to the side of the baffle 16 away from the pins 17 .

[0065] In a preferred embodiment of the square battery structure, the core package 6 includes a stacked separator, a positive electrode sheet and a negative electrode sheet.

[0066] In a preferred embodiment of the square battery structure, the insulating sheet 5 is arranged between the core package 6 and the inner wall of the shell 4.

[0067] In one embodiment, the positive and negative poles of the top cover 1 are connected to the positive and negative connecting pieces, and the wings of the connecting pieces are connected to the positive and negative ears of the core package 6. The pins 17 of the bracket 13 are connected to the top cover 1, and the bracket 13 is located below the liquid injection hole of the top cover; according to design requirements, the top cover 1 can be made into a double-bracket structure, which is located on both sides of the explosion-proof valve 14 of the top cover 1. The pins 17 of the bracket 13 are welded to the top cover 1, and the bracket 13 is located below the liquid injection hole of the top cover. The lower plastic layer 11 is hollowed out at this location to avoid interference with the bracket 13. The positive pole ear 3 of the core package 6 is welded to the wings of the positive connecting piece 2, and the head of the positive connecting piece 2 is welded to the positive pole 9, and then the core is combined. The boss of the lower plastic layer 11 and the bracket 13 press the core package 6, and then the insulating sheet 5 is wrapped, and finally the shell is put into the shell to complete the shell cover welding.

[0068] In one embodiment, the bracket 13 has two structural options. Figure 8 As shown, the pin 17 of the bracket 13 is made of metal and is welded to the cover 10. The lower half of the pin 17 and the baffle 16 of the bracket 13 are made of metal using nano injection molding and nano molding technology, which can ensure the structural strength of the bracket 13 and also provide insulation. Figure 9 The bracket 13 is made entirely of metal, and a high-temperature insulating tape layer 18 is applied to the bottom of the baffle 16 of the bracket 13. The number of pins 17 of the bracket 13 is 3 or more, and the number of pins 17 welded to the top cover 1 is selected based on the required structural strength.

[0069] In one embodiment, the core pack 6 is composed of a diaphragm, a positive electrode sheet, and a negative electrode sheet. It is formed by stacking a layer of diaphragm, a layer of negative electrode sheet, a layer of diaphragm, and a layer of positive electrode sheet in a reciprocating manner. The positive electrode tab 3 extends from one side of the positive electrode sheet, and the negative electrode tab 7 extends from the other side of the negative electrode sheet. The internal structure of this battery is composed of a double core pack 6, such as Figure 1 As shown, the tabs of the two core packs 6 are folded and located on both sides, forming a "C" shape. Figure 7 As shown, the core package 6 is formed by wrapping the positive electrode sheet and the negative electrode sheet with a diaphragm, and a lamination process is adopted. A positive electrode tab 3 extends from one side of the positive electrode sheet, and a negative electrode tab 7 extends from one side of the negative electrode sheet.

[0070] Finally, it should be noted that the described embodiments are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making any creative work are within the scope of protection of this application.

[0071] The above description is merely illustrative of certain exemplary embodiments of the present invention. It goes without saying that those skilled in the art will be able to modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and description are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A square battery structure, characterized in that: These include, The shell is a square open structure. A core pack is contained in the shell, and includes a negative electrode tab and a positive electrode tab. A negative electrode connecting piece, which is connected to the negative electrode tab, A positive electrode connecting piece, which is connected to the positive electrode tab, A top cover is provided on the opening of the housing, and the top cover includes: The cover plate and the lower plastic layer stacked thereunder cover the opening. A negative electrode column, which is provided on the cover plate and connected to the negative electrode connecting piece, A positive electrode column, which is provided on the cover plate and connected to the positive electrode connecting piece, The top cover liquid injection hole is provided through the cover plate and the lower plastic layer is hollowed out corresponding to the top cover liquid injection hole. A bracket is located in the hollow part, and the bracket includes a plurality of pins connected to the inner top wall of the cover plate and a baffle connected to the pins.

2. A square battery structure according to claim 1, characterized in that: The cover plate is further provided with an explosion-proof valve, and a grid away from the cover plate is provided on the lower plastic layer at a position corresponding to the explosion-proof valve.

3. A square battery structure according to claim 2, characterized in that: The explosion-proof valve is provided with an explosion-proof valve protective film.

4. A square battery structure according to claim 2, characterized in that: A pair of brackets are symmetrically distributed on both sides of the explosion-proof valve.

5. The square battery structure according to claim 1, characterized in that: The negative electrode connecting piece includes wings connected to the negative electrode tab and a head connected to the negative electrode column.

6. The square battery structure according to claim 1, characterized in that: The positive electrode connecting piece includes wings connected to the positive electrode tab and a head connected to the positive electrode column.

7. The square battery structure according to claim 1, characterized in that: The lower plastic layer is provided with bosses at both ends of a side away from the cover plate.

8. The square battery structure according to claim 1, characterized in that: A high-temperature insulating tape layer is attached to a side of the baffle away from the pins.

9. The square battery structure according to claim 1, characterized in that: The core package includes a laminated separator, a positive electrode sheet and a negative electrode sheet.

10. The square battery structure according to claim 1, characterized in that: The insulating sheet is arranged between the core package and the inner wall of the shell.

Images