Battery module and preparation method thereof

Abstract

The invention relates to the technical field of batteries, in particular to a battery module and a preparation method thereof. The battery module comprises a battery cell body, a Breaker assembly and an insulating shell, a tab group is arranged at one end of the battery cell body and comprises a first tab and a second tab, and first insulating gummed paper is arranged at one end, close to the tab group, of the battery cell body; the Breaker assembly is adhered to the first insulating gummed paper and comprises a fuse, a first connecting piece and a second connecting piece, the fuse is positioned on one side close to the cell body, the first connecting piece is connected with the free end of the first tab, and the first connecting piece and the first tab are bent along the length direction of the first connecting piece; the insulating shell is arranged on the battery cell body in an injection molding manner and wraps the first tab, the first connecting piece, the fuse and part of the second connecting piece; wherein a shrink-proof opening is formed in the insulating shell, and the distance between the inner wall of the shrink-proof opening and the inner protection part is larger than or equal to the minimum distance needed by hot melt glue walking. Through the above structure, the bimetallic strip of the Breaker assembly is not afraid of a high-temperature and high-humidity environment and is not oxidized to lose efficacy any more.

Description

Technical Field

[0001] The present invention relates to the field of battery technology, and in particular to a battery module and a preparation method thereof. Background Art

[0002] As the capacity, charge and discharge rate, and temperature of lithium batteries increase, people are more concerned about the safety performance of lithium batteries. For safety reasons, the battery cells need to be connected to a breaker component (fuse) for safety protection.

[0003] After the breaker assembly is installed on the battery, the bimetallic strip in the breaker assembly may be oxidized and fail when the battery is used in a high temperature and high humidity environment, thus affecting the performance and life of the battery. Summary of the invention

[0004] The technical problem to be solved by the embodiments of the present invention is to provide a battery module and a preparation method thereof, so as to solve the problem in the prior art that after a breaker component is set on the battery, the bimetallic strip in the breaker component will be oxidized and fail when the battery is used in a high temperature and high humidity environment, thereby affecting the performance and life of the battery.

[0005] The present invention discloses a battery module, comprising: a battery cell body, a breaker assembly and an insulating shell, wherein a tab group is arranged at one end of the battery cell body, the tab group comprises a first tab and a second tab arranged oppositely, and a first insulating tape is arranged at one end of the battery cell body close to the tab group; the breaker assembly is bonded to the first insulating tape, and comprises a fuse, a first connector and a second connector arranged at both ends of the fuse, the fuse is located on one side close to the battery cell body, the free end of the first connector is connected to the free end of the first tab, and the first connector and the first tab are bent along the length direction of the first connector; the insulating shell is injection-molded on the battery cell body at low temperature by hot melt adhesive, and the insulating shell wraps the first tab, the first connector, the fuse and part of the second connector; the first tab, the first connector, the fuse and part of the second connector wrapped in the insulating shell constitute an inner protection part protected by the insulating shell; or,

[0006] The insulating shell encloses the first pole lug, the first connector, the fuse, part of the second connector, and part of the second pole lug, and the first pole lug, the first connector, the fuse, part of the second connector, and part of the second pole lug enclosed in the insulating shell constitute an inner protection portion protected by the insulating shell;

[0007] Among them, an anti-shrinkage port is formed on the insulating shell, and the distance between the inner wall of the anti-shrinkage port and the inner protection part is greater than or equal to the minimum distance required for the hot melt adhesive to flow.

[0008] Optionally, the outer corner area on the insulating shell has a smooth transition.

[0009] Optionally, the anti-shrinkage opening is an anti-shrinkage groove that passes through one side of the insulating shell; or, the anti-shrinkage opening is an anti-shrinkage notch that passes through multiple adjacent sides of the insulating shell; or, the anti-shrinkage opening is an anti-shrinkage hole that passes through two opposite sides of the insulating shell;

[0010] The corner area inside the anti-shrinkage opening, the corner area between the anti-shrinkage opening and the area of ​​the insulating shell adjacent to the anti-shrinkage groove, and the corner area between the side walls of the insulating shell all have smooth transitions.

[0011] Optionally, the wall thickness of the insulating shell is h1, and the value range of h1 is 0.4 mm-4.5 mm.

[0012] Optionally, a difference in wall thickness between a corner region of the insulating shell and a peripheral region of the insulating shell is less than 25%.

[0013] Optionally, the projection of the insulating shell in the thickness direction of the battery cell body is a chamfered rectangle, and the insulating shell includes a first shell portion, a second shell portion and a third shell portion sequentially connected along the width direction of the battery cell body;

[0014] The first shell portion extends from one side of the inner protection portion in the width direction of the battery cell body, along the width direction of the battery cell body, in a direction away from the inner protection portion;

[0015] The third shell portion extends from the other side of the inner protection portion in the width direction of the battery cell body, along the width direction of the battery cell body, in a direction away from the inner protection portion;

[0016] The width of the first shell portion in the width direction of the battery cell body is consistent with the width of the third shell portion in the width direction of the battery cell body, and is greater than the wall thickness of the second shell portion.

[0017] Optionally, the Breaker assembly is a U-shaped structure, the first connector and the first pole ear are attached and bent as a whole in the length direction of the battery body, and the first connector is located on the inner side of the bend; the second connector is located on a side of the second pole ear close to the first pole ear, and a gap is maintained between the second pole ear and the second connector;

[0018] The insulating shell encloses the first pole lug, the first connecting member, the fuse and part of the second connecting member;

[0019] The anti-shrinkage port is arranged between the first connecting piece, the fuse and the second connecting piece, and the distance from the anti-shrinkage port to the first connecting piece, the fuse and the second connecting piece is greater than or equal to the minimum distance required for the hot melt adhesive to flow.

[0020] Optionally, the second connector is bent in the width direction of the battery body so that the bent section of the second connector is located on a side of the first connector away from the first pole lug and another section of the second connector is located on a side away from the second pole lug;

[0021] The insulating shell encloses the first pole lug, the first connecting member, the fuse, a portion of the second connecting member and a portion of the second pole lug;

[0022] The anti-shrinkage port is arranged between the second connecting piece, the fuse and the second pole ear, and the distance from the anti-shrinkage port to the second connecting piece, the fuse and the second pole ear is greater than or equal to the minimum distance required for the hot melt adhesive to flow.

[0023] The present invention also discloses a method for preparing a battery module, comprising: taking a battery cell body, wherein a tab group is arranged at one end of the battery cell body, the tab group comprises a first tab and a second tab which are arranged opposite to each other, and a first insulating tape is arranged on one side of the battery cell body close to the tab group; taking a Breaker component, wherein the Breaker component is a U-shaped structure, the Breaker component is arranged between the first tab and the second tab, the Breaker component comprises a fuse, a first connector and a second connector which are arranged at both ends of the fuse, and the free end of the first connector and the free end of the first tab are welded; the first connector and the first tab are bent along the length direction of the first connector; an injection-molded insulating shell is arranged at one end of the Breaker component on the battery cell body, the insulating shell wraps the first tab, the first connector, the fuse and part of the second connector; the outer corner area on the insulating shell has a smooth transition; wherein the wall thickness of the insulating shell is h1, and the value range of h1 is 0.4mm-4.5mm.

[0024] The present invention further discloses a method for preparing a battery module, comprising: taking a battery cell body, wherein a pole ear group is arranged at one end of the battery cell body, wherein the pole ear group includes a first pole ear and a second pole ear, and a first insulating tape is arranged on one side of the battery cell body close to the pole ear group; taking a breaker assembly, wherein the breaker assembly is a return-to-original-position structure, wherein the breaker assembly includes a fuse, a first connector and a second connector arranged at both ends of the fuse, wherein the free end of the first connector and the free end of the first pole ear are welded, and the second connector extends to the outside of the battery cell body along the length direction of the battery cell body; wherein the first connector and the first pole ear are bent along the length direction of the first connector; wherein the second connector is bent along the extension direction of the second connector so as to bend the second connector back; wherein an injection-molded insulating shell is arranged at one end of the breaker assembly on the battery cell body, wherein the insulating shell wraps the first pole ear, the first connector, the fuse, a part of the second connector and a part of the second pole ear; wherein the outer corner area on the insulating shell has a smooth transition; wherein the wall thickness of the insulating shell is h1, and the value range of h1 is 0.4 mm-4.5 mm.

[0025] Compared with the prior art, the battery module and the preparation method thereof provided by the embodiments of the present invention have the following beneficial effects: the setting of the Breaker component can protect the battery cell body from the influence of overload and overheating, and ensure the safety and reliability of the battery cell body. In the process of setting the Breaker component on the battery cell body, a first insulating tape is set at one end of the battery cell body close to the pole ear group, and the fuse is pre-fixed on the battery cell body through the first insulating tape, and the free end of the first connector and the free end of the first pole ear are connected, and the first connector and the first pole ear are bent along the length direction of the first connector, and an insulating shell is injection-molded at one end of the Breaker component on the battery cell body, and the insulating shell wraps the first pole ear, the first connector, the fuse and part of the second connector to form an inner protection part protected by the insulating shell, or the insulating shell wraps the first pole ear, the first connector, the fuse, part of the second connector and part of the second pole ear to form an inner protection part protected by the insulating shell; during the injection molding process, an anti-shrinkage port is formed on the insulating shell. , avoiding the wall thickness of the insulating shell being too thick, shrinkage and deformation, etc., and can reduce the cold shortage time of the rubber material and increase production efficiency. At the same time, the distance between the inner wall of the anti-shrinkage port and the inner protection part is set to be ≥ the minimum distance required for the hot melt adhesive to flow, which is convenient for the flow of the rubber material and avoids the occurrence of undesirable phenomena such as insufficient glue, lack of glue, and difficulty in glue flow; the insulating shell wraps the first pole ear, the first connecting piece and part of the second connecting piece, or the insulating shell wraps the first pole ear, the first connecting piece, the fuse, part of the second connecting piece and part of the second pole ear, effectively encapsulating the Breaker component and the battery body into one, enhancing the mechanical strength of the Breaker component, making the Breaker component not easily damaged by external force, and at the same time preventing the Breaker component from piercing the battery body when the battery module falls, and effectively isolating the Breaker component from the external environment, so that the bimetallic strip of the Breaker component is no longer afraid of oxidation failure due to high temperature and high humidity use environment, thereby ensuring the performance and life of the battery module. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments, in which:

[0027] Figure 1 It is a schematic diagram of the structure of a Breaker component of a U-shaped structure provided by an embodiment of the present invention;

[0028] Figure 2 It is a schematic diagram of a process for preparing a battery module provided by an embodiment of the present invention;

[0029] Figure 3 This is one of the structural schematic diagrams of a battery module provided by an embodiment of the present invention;

[0030] Figure 4This is a second structural schematic diagram of a battery module provided by an embodiment of the present invention;

[0031] Figure 5 is a cross-sectional view of a battery module provided by one embodiment of the present invention;

[0032] Figure 6 is a schematic structural diagram of a Breaker component of a return-to-original-position structure provided by another embodiment of the present invention;

[0033] Figure 7 It is a bending diagram of a Breaker component of a return-to-origin structure provided by another embodiment of the present invention;

[0034] Figure 8 is a schematic flow chart of a method for preparing a battery module according to another embodiment of the present invention;

[0035] Fig. 9 is a structural schematic diagram of a battery module provided by another embodiment of the present invention;

[0036] Fig.10 is a cross-sectional view of a battery module provided by another embodiment of the present invention;

[0037] Fig.11 This is a test chart of EDS testing of the bimetallic strip of the Breaker component after the battery module obtained in Examples 1 to 3 of the present invention was stored under high temperature and high humidity (60° C., 90% RH) conditions for 1000 hours;

[0038] Fig.12 It is a state diagram of the bimetallic strip of the Breaker component after the battery module obtained in Examples 1 to 3 of the present invention is stored under high temperature and high humidity (60° C., 90% RH) conditions for 1000 hours;

[0039] Fig.13 This is an elemental analysis diagram of the bimetallic strip of the Breaker component after the battery module obtained in Examples 1 to 3 of the present invention is stored under high temperature and high humidity (60° C., 90% RH) conditions for 1000 hours;

[0040] Fig.14 yes Fig.13 The proportion of each element in the graph;

[0041] Fig.15 This is a schematic diagram of the connection structure between the corner areas of the insulating shell provided in Comparative Example 1;

[0042] Fig.16 This is a schematic diagram of the connection structure between the corner areas of the insulating shell provided in Example 2.

[0043] Fig.17It is a schematic diagram of the connection structure of the insulating shell provided by one embodiment of the present invention at the anti-shrinkage outlet and the corner area around it.

[0044] The reference numerals in the figures are:

[0045] 10. Battery cell body; 110. First pole ear; 111. First insulating tape; 120. Second pole ear; 20. Breaker assembly; 210. Fuse; 220. First connector; 2201. First notch; 2202. Second notch; 230. Second connector; 30. Insulating shell; 301. Shrinkage prevention port; 310. First shell; 320. Second shell; 330. Third shell. DETAILED DESCRIPTION

[0046] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. Now, in conjunction with the accompanying drawings, the preferred embodiments of the present invention are described in detail.

[0047] An embodiment of the present invention provides a battery module, such as Figures 1 to 10 As shown, it includes a battery body 10, a breaker component 20, and an insulating shell 30; a pole ear group is arranged at one end of the battery body 10, and the pole ear group includes a first pole ear 110 and a second pole ear 120 arranged oppositely, and a first insulating adhesive tape 111 is arranged at one end of the battery body 10 close to the pole ear group; the breaker component 20 is bonded to the first insulating adhesive tape 111, and includes a fuse 210, a first connector 220 and a second connector 230 arranged at both ends of the fuse 210, the fuse 210 is located on the side close to the battery body 10, the free end of the first connector 220 is connected to the free end of the first pole ear 110, and the first connector 220 and the first pole ear 110 are bent along the length direction of the first connector 220; the insulating shell 30 is low-temperature injection molded on the battery body 10 using hot melt adhesive, and the insulating shell 30 wraps the first pole ear 110. A pole ear 110, a first connector 220, a fuse 210 and a part of the second connector 230; the first pole ear 110, the first connector 220, the fuse 210 and a part of the second connector 230 wrapped in the insulating shell 30 constitute an inner protection part protected by the insulating shell 30; or, the insulating shell 30 wraps the first pole ear 110, the first connector 220, the fuse 210, a part of the second connector 230 and a part of the second pole ear 120, and the first pole ear 110, the first connector 220, the fuse 210, a part of the second connector 230 and a part of the second pole ear 120 wrapped in the insulating shell 30 constitute an inner protection part protected by the insulating shell 30; wherein, an anti-shrinkage port 301 is formed on the insulating shell 30, and the distance between the inner wall of the anti-shrinkage port 301 and the inner protection part is ≥ the minimum distance required for the hot melt adhesive to flow.

[0048] The setting of the Breaker component 20 can protect the battery body 10 from overload and overheating, and ensure the safety and reliability of the battery body 10. In the process of setting the Breaker component 20 on the battery body 10, a first insulating adhesive paper 111 is set at one end of the battery body 10 close to the pole ear group, and the fuse 210 is pre-fixed on the battery body 10 through the first insulating adhesive paper 111, and the free end of the first connector 220 is connected to the free end of the first pole ear 110, and The first connector 220 and the first pole ear 110 are bent along the length direction of the first connector 220, and an insulating shell 30 is injection-molded at one end of the breaker assembly 20 on the battery cell body 10. The insulating shell 30 wraps the first pole ear 110, the first connector 220, the fuse 210 and part of the second connector 230 as an inner protection part protected by the insulating shell 30, or the insulating shell 30 wraps the first pole ear 110, the first connector 220, the fuse 210, part of the second connector 230 and part of the inner protection part protected by the insulating shell 30. The second pole ear 120 is an inner protection part protected by the insulating shell 30; during the injection molding process, an anti-shrinkage port 301 is formed on the insulating shell 30 to avoid the wall thickness of the insulating shell 30 being too thick, shrinking and deforming, etc., and can reduce the cold shortage time of the adhesive and increase production efficiency. At the same time, the distance between the inner wall of the anti-shrinkage port 301 and the inner protection part is set to be ≥ the minimum distance required for the hot melt adhesive to facilitate the flow of the adhesive and avoid the occurrence of insufficient adhesive, lack of adhesive, difficulty in adhesive flow and other adverse phenomena; the Breaker component 20 is effectively encapsulated with the battery body 10 as a whole, the mechanical strength of the Breaker component 20 is enhanced, and the Breaker component 20 is not easily damaged by external forces. At the same time, it can also prevent the Breaker component 20 from piercing the battery body 10 when the battery module falls, and effectively isolate the Breaker component 20 from the external environment, so that the bimetallic strip of the Breaker component 20 is no longer afraid of oxidation failure due to the high temperature and high humidity use environment, thereby ensuring the performance and life of the battery module.

[0049] More specifically, the outer corner area of ​​the insulating shell 30 has a smooth transition, which facilitates the flow of the rubber material and further improves the production efficiency of the insulating shell 30.

[0050] More specifically, the anti-shrinkage opening 301 is an anti-shrinkage groove that passes through one side of the insulating shell 30; or, the anti-shrinkage opening 301 is an anti-shrinkage notch that passes through multiple adjacent sides of the insulating shell 30, or, the anti-shrinkage opening 301 is an anti-shrinkage hole that passes through two opposite sides of the insulating shell 30; the corner area inside the anti-shrinkage opening 301, the corner area between the anti-shrinkage opening 301 and the area adjacent to the anti-shrinkage groove of the insulating shell 30 (such as Fig.17 As shown), the corner areas between the side walls of the insulating shell 30 are smoothly transitioned.

[0051] The above arrangement can avoid the wall thickness of the insulating shell 30 being too thick, shrinking and deforming, etc. during the injection molding process, and can reduce the cold shortage time of the rubber material, increase production efficiency, and facilitate the flow of the rubber material, avoiding the occurrence of undesirable phenomena such as insufficient rubber material, lack of rubber material, and difficulty in moving the rubber material. The production efficiency and sealing performance of the insulating shell 30 are improved, and the performance and life of the battery are improved.

[0052] More specifically, the wall thickness of the insulating shell 30 is h1, and the value range of h1 is 0.4 mm-4.5 mm. h1 can be 0.4 mm, 0.5 mm, 0.8 mm, 1 mm, 2 mm, 3 mm, 4 mm, or 4.5 mm.

[0053] Among them, the above-mentioned limitation on the wall thickness of the side wall of the insulating shell 30 facilitates the flow of the rubber during the injection molding process of the insulating shell 30, avoids defects such as insufficient rubber, lack of rubber, and difficulty in moving the rubber, and further improves the injection molding efficiency and molding effect of the insulating shell 30.

[0054] More specifically, the difference in wall thickness between the corner area of ​​the insulating shell 30 and the surrounding part of the insulating shell 30 is less than 25%. The wall thickness difference can be 25%, 20%, 15%, 10%, 5%, or 0.

[0055] Among them, the above definition facilitates the flow of the rubber during the injection molding process of the insulating shell 30 , which can further improve the injection molding efficiency and molding effect of the insulating shell 30 .

[0056] More specifically, the projection of the insulating shell 30 in the thickness direction of the cell body 10 is a chamfered rectangle, and the insulating shell 30 includes a first shell portion 310, a second shell portion 320, and a third shell portion 330 connected in sequence along the width direction of the cell body 10; the first shell portion 310 extends from one side of the inner protection portion in the width direction of the cell body 10 to a direction away from the inner protection portion along the width direction of the cell body 10; the third shell portion 330 extends from the other side of the inner protection portion in the width direction of the cell body 10 to a direction away from the inner protection portion along the width direction of the cell body 10; the width of the first shell portion 310 in the width direction of the cell body 10 is consistent with the width of the third shell portion 330 in the width direction of the cell body 10, and is greater than the wall thickness of the second shell portion 320. Preferably, the wall thickness of each side wall of the second shell portion 320 is consistent.

[0057] In this embodiment, a first notch 2201 is formed on the first connecting member 220 , and the first connecting member 220 and the first electrode tab 110 are bent along the first notch 2201 in the length direction of the first connecting member 220 .

[0058] The first notch 2201 is provided to facilitate operation so as to quickly bend the first connector 220 and the first tab 110 .

[0059] More specifically, when the Breaker component 20 is a U-shaped structure, the first connector 220 and the first pole ear 110 are attached and bent as a whole in the length direction of the battery cell body 10, and the first connector 220 is located on the inner side of the bend; the second connector 230 is located on the side of the second pole ear 120 close to the first pole ear 110, and a gap is maintained between the second pole ear 120 and the second connector 230; the insulating shell 30 wraps the first pole ear 110, the first connector 220, the fuse 210 and part of the second connector 230; the anti-shrinkage port 301 is provided between the first connector 220, the fuse 210 and the second connector 230, and the distance from the anti-shrinkage port 301 to the first connector 220, the fuse 210 and the second connector 230 is ≥ the minimum distance required for the hot melt adhesive to flow.

[0060] The breaker assembly 20 is a U-shaped structure, and is mainly used in a cell body 10 where the distance between the first pole tab 110 and the second pole tab 120 is relatively large. The breaker assembly 20 is located between the first pole tab 110 and the second pole tab 120 , and the breaker assembly 20 does not contact the second pole tab 120 .

[0061] More specifically, the second connector 230 is bent in the width direction of the battery body 10 so that the bent section of the second connector 230 is located on the side of the first connector 220 away from the first pole ear 110, and the other section of the second connector 230 is located on the side away from the second pole ear 120; the insulating shell 30 wraps the first pole ear 110, the first connector 220, the fuse 210, part of the second connector 230 and part of the second pole ear 120; the anti-shrinkage port 301 is provided between the second connector 230, the fuse 210 and the second pole ear 120, and the distance from the anti-shrinkage port 301 to the second connector 230, the fuse 210 and the second pole ear 120 is ≥ the minimum distance required for the hot melt adhesive to flow.

[0062] Among them, the above-mentioned Breaker component 20 is a return-to-original structure, which is mainly used in the battery body 10 with a small distance between the first pole ear 110 and the second pole ear 120. The second connecting member 230 of the above-mentioned Breaker component 20 will extend to the outside of the battery body 10 along the width direction of the battery body 10. After the Breaker component 20 is installed, the second connecting member 230 is bent at the second notch 2202 along the extension direction of the second connecting member 230 to make the second connecting member 230 bend back. The insulating shell 30 also wraps part of the second pole ear 120, ensuring that the insulating shell 30 fixes the Breaker component 20 on the battery body 10.

[0063] The provision of the anti-shrinkage port 301 in this embodiment can reduce the cooling time during the injection molding process, and can prevent the side wall of the insulating shell 30 from being too thick, resulting in shrinkage and deformation, and the anti-shrinkage port 301 is located between the first connector 220 and the second connector 230 on the insulating shell 30, which can ensure that the provision of the anti-shrinkage port 301 on the insulating shell 30 will not interfere with the wrapping of the first connector 220 and the second connector 230 by the insulating shell 30, thereby ensuring the fit between the insulating shell 30 and the Breaker assembly 20, strengthening the mechanical structure between the Breaker assembly 20 and the battery cell body 10, and making the structure more solid and reliable, and not easily damaged by external forces.

[0064] like Figure 2 As shown, the present embodiment also discloses a method for preparing a battery module, comprising: taking a battery cell body 10, wherein a tab group is provided at one end of the battery cell body 10, wherein the tab group comprises a first tab 110 and a second tab 120 which are arranged opposite to each other, and a first insulating adhesive tape 111 is provided on a side of the battery cell body 10 close to the tab group; taking a breaker assembly 20, wherein the breaker assembly 20 is a U-shaped structure, and the breaker assembly 20 is arranged between the first tab 110 and the second tab 120, and the breaker assembly 20 comprises a fuse 210, a first connector 220 and a second connector 230 which are arranged at both ends of the fuse 210, and a first notch 2201 is formed on the first connector 220, and the first connector 230 is provided with a first notch 2201. The free end of the component 220 and the free end of the first pole ear 110 are welded; the first connector 220 and the first pole ear 110 are bent at the first notch 2201 along the length direction of the first connector 220; an injection-molded insulating shell 30 is arranged at one end of the Breaker component 20 on the battery body 10, and the insulating shell 30 wraps the first pole ear 110, the first connector 220, the fuse 210 and part of the second connector 230; the outer corner area on the insulating shell 30 has a smooth transition; wherein, the wall thickness of the insulating shell 30 is h1, the value range of h1 is 0.4mm-4.5mm, and h1 can be 0.4mm, 0.5mm, 0.8mm, 1mm, 2mm, 3mm, 4mm, 4.5mm.

[0065] like Figure 8As shown, the embodiment of the present application further discloses a method for preparing a battery module, comprising: taking a battery cell body 10, wherein a pole ear group is arranged at one end of the battery cell body 10, the pole ear group comprises a first pole ear 110 and a second pole ear 120, and a first insulating adhesive tape 111 is arranged on a side of the battery cell body 10 close to the pole ear group; taking a breaker assembly 20, wherein the breaker assembly 20 is a return-to-original structure, the breaker assembly 20 comprises a fuse 210, a first connector 220 and a second connector 230 arranged at both ends of the fuse 210, the free end of the first connector 220 and the free end of the first pole ear 110 are welded, the first connector 220 is arranged with a first notch 2201, the second connector 230 extends along the length direction of the battery cell body 10 to the outside of the battery cell body 10, and the second connector 230 is arranged with a first notch 2201. two notches 2202; along the length direction of the first connector 220, the first connector 220 and the first pole ear 110 are bent at the first notch 2201; along the extension direction of the second connector 230, the second connection is bent at the second notch 2202 to make the second connection bend back; an injection-molded insulating shell 30 is set at one end of the Breaker component 20 on the battery body 10, and the insulating shell 30 wraps the first pole ear 110, the first connector 220, the fuse 210, part of the second connector 230 and part of the second pole ear 120; the outer corner area on the insulating shell 30 has a smooth transition, wherein the wall thickness of the insulating shell 30 is h1, the value range of h1 is 0.4mm-4.5mm, and h1 can be 0.4mm, 0.5mm, 0.8mm, 1mm, 2mm, 3mm, 4mm, 4.5mm.

[0066] Embodiment 1:

[0067] Take a cell body 10, one end of the cell body 10 is provided with a pole ear group, the pole ear group includes a first pole ear 110 and a second pole ear 120, and a first insulating tape 111 is provided on the side close to the cell body 10 and close to the pole ear group; take a breaker assembly 20, the breaker assembly 20 is a U-shaped structure or a return-to-original structure, the breaker assembly 20 is bonded to the first insulating tape 111, the breaker assembly 20 includes a fuse 210, a first connector 220 and a second connector 230 provided at both ends of the fuse 210, the free end of the first connector 220 and the free end of the first pole ear 110 are welded, a first notch 2201 is provided on the first connector 220, and the second connector 230 extends along the length direction of the cell body 10 to the outside of the cell body 10, when the breaker assembly 20 is a return-to-original structure, a second notch 2202 is provided on the second connector 230, and a second notch 2203 is provided along the first connector 220 In the length direction, the first connector 220 and the first pole ear 110 are bent at the first notch 2201; along the extension direction of the second connector 230 of the Breaker component 20 of the return-to-original structure, the second connection is bent at the second notch 2202 to make the second connection bend back; an insulating shell 30 is formed on the battery body 10 using a hot melt adhesive low-temperature injection molding at one end of the Breaker component 20, and the insulating shell 30 wraps the first pole ear 110, the first connector 220, the fuse 210, part of the second connector 230 and part of the second pole ear 120; the first pole ear 110, the first connector 220, the fuse 210 and part of the second connector 230 wrapped in the insulating shell 30 constitute an inner protection part protected by the insulating shell 30; an anti-shrinkage port 301 is formed on the insulating shell 30, and the distance between the inner wall of the anti-shrinkage port 301 and the inner protection part is ≥ the minimum distance required for the hot melt adhesive to pass, and the outer corner area on the insulating shell 30 has a smooth transition (such as Fig.17 As shown), the wall thickness of the insulating shell 30 is h1, and the value of h1 is 0.4 mm.

[0068] Embodiment 2:

[0069] The difference between Example 2 and Example 1 is that the value of h1 is 0.5 mm, and the other conditions remain unchanged.

[0070] Embodiment 3:

[0071] The difference between Example 3 and Example 1 is that the value of h1 is 4.5 mm, and the other conditions remain unchanged.

[0072] Comparative Example 1:

[0073] The difference between Comparative Example 1 and Example 2 is that the outer corner area on the insulating shell 30 is a non-smooth transition.

[0074] Comparative Example 2:

[0075] The difference between Comparative Example 2 and Example 2 is that the outer corner area of ​​the insulating shell 30 is a non-smooth transition, and the difference in wall thickness between the corner area of ​​the insulating shell 30 and the surrounding part of the insulating shell 30 is 30%.

[0076] In the preparation process of the battery module obtained in the above embodiments 1 to 3, the setting of the Breaker component 20 can protect the battery cell body 10 from the influence of overload and overheating, and ensure the safety and reliability of the battery cell body 10. The set insulating shell 30 effectively encapsulates the Breaker component 20 and the battery cell body 10 as a whole, thereby enhancing the mechanical strength of the Breaker component 20, making the Breaker component 20 not easily damaged by external forces, and at the same time preventing the Breaker component 20 from piercing the battery cell body 10 when the battery module falls, and effectively isolating the Breaker component 20 from the external environment, so that the bimetallic strip of the Breaker component 20 is no longer afraid of oxidation failure in the high temperature and high humidity use environment, thereby improving the service life of the battery module.

[0077] Please refer to the attached Figures 11 to 14 , is a test diagram of the bimetallic strip of the Breaker component 20 when the battery module prepared by the preparation method of Examples 1 to 3 is stored under high temperature and high humidity conditions for 1000 hours.

[0078] according to Fig.11 It can be seen that the elements of the bimetallic strip of the Breaker assembly 20 of the battery module of the present embodiments 1 to 3 are evenly distributed, and it can be seen that the red and green parts are evenly distributed, indicating that the contents of oxygen and manganese are comparable.

[0079] according to Fig.12 It can be seen that the surface of the bimetallic strip of the Breaker assembly 20 of the battery module obtained in Examples 1 to 3 is smooth, and the bimetallic strip itself is not damaged.

[0080] according to Fig.13 , Fig.14 It can be seen that the oxygen content in the bimetallic strip of the Breaker assembly 20 of the battery module obtained in Examples 1 to 3 is only 2.62%.

[0081] The bimetallic strip of the Breaker assembly 20 of this embodiment is not afraid of oxidation failure in a high temperature and high humidity (60° C., 90% RH) usage environment, thereby improving the overall performance and service life of the battery module.

[0082] In the process of preparing the battery module of Comparative Example 1, the insulating shell 30 has the following effects: the injection path is blocked and the rubber material is blocked, as shown in Table 1.

[0083] The prepared battery module has the following undesirable phenomena: the insulating shell 30 has insufficient glue, lack of glue, and whitening, as shown in Table 1.

[0084] After the obtained battery module was stored under high temperature and high humidity conditions (60°C, 90% RH) for 1000 hours, the areas where the glue was insufficient and exposed at the tabs were obviously oxidized, the TCO bimetallic strip had oxidized powder, and the TDS elemental analysis showed an oxygen content of 18.41%, as shown in Table 2.

[0085] In the process of preparing the battery module of Comparative Example 2, the insulating shell 30 has the following effects: uneven wall thickness of the rubber material and uneven cooling, which can be referred to in Table 1.

[0086] The prepared battery module has the following undesirable phenomena: the insulating shell 30 is warped, wavy, and shrunk, as shown in Table 1.

[0087] After the obtained battery module was stored under high temperature and high humidity conditions (60°C, 90% RH) for 1000 hours, shrinkage and warping were found, the insulating shell 30 and the battery body 10 were debonded, and there was a gap. The TCO bimetallic strip had traces of oxidation, and the oxygen content of the TDS elemental analysis was 12.65%, which can be referred to Table 2.

[0088] Table 1

[0089] project Effect of the presence of an insulating shell Insulation shell defects Comparative Example 1 The injection path is blocked and the rubber is blocked The insulating shell has insufficient glue, lack of glue, or white spots. Comparative Example 2 Uneven wall thickness and uneven cooling of the rubber compound Insulation shell warping, wavy lines, shrinkage

[0090] Table 2

[0091]

[0092] It should be understood that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. For those skilled in the art, the technical solutions described in the above embodiments can be modified, or some of the technical features therein can be replaced by equivalents; and all these modifications and replacements should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A battery module, characterized in that: include: A cell body, wherein a tab group is disposed at one end of the cell body, the tab group comprises a first tab and a second tab that are disposed opposite to each other, and a first insulating adhesive tape is disposed at one end of the cell body close to the tab group; A Breaker component, the Breaker component is bonded to the first insulating tape, the Breaker component comprises a fuse, a first connector and a second connector provided at both ends of the fuse, the fuse is located at one side of the battery body, the free end of the first connector is connected to the free end of the first pole ear, and the first connector and the first pole ear are bent along the length direction of the first connector; The insulating shell is injection-molded on the battery body at low temperature by using hot melt adhesive; The insulating shell wraps the first pole lug, the first connector, the fuse and part of the second connector, and the first pole lug, the first connector, the fuse and part of the second connector wrapped in the insulating shell become an inner protection part protected by the insulating shell; or, The insulating shell encloses the first pole lug, the first connector, the fuse, part of the second connector, and part of the second pole lug, and the first pole lug, the first connector, the fuse, part of the second connector, and part of the second pole lug enclosed in the insulating shell constitute an inner protection portion protected by the insulating shell; Wherein, an anti-shrinkage port is formed on the insulating shell, and the distance between the inner wall of the anti-shrinkage port and the inner protection part is greater than or equal to the minimum distance required for the hot melt adhesive to flow.

2. The battery module according to claim 1, characterized in that: The outer corner area of ​​the insulating shell has a smooth transition.

3. The battery module according to claim 2, characterized in that: The anti-shrinkage opening is an anti-shrinkage groove that passes through one side of the insulating shell; or, the anti-shrinkage opening is an anti-shrinkage notch that passes through multiple adjacent sides of the insulating shell; or, the anti-shrinkage opening is an anti-shrinkage hole that passes through two opposite sides of the insulating shell; The corner area inside the anti-shrinkage opening, the corner area between the anti-shrinkage opening and the area of ​​the insulating shell adjacent to the anti-shrinkage groove, and the corner area between the side walls of the insulating shell all have smooth transitions.

4. The battery module according to claim 3, characterized in that: The wall thickness of the insulating shell is h1, and the value range of h1 is 0.4mm-4.5mm.

5. The battery module according to claim 4, characterized in that: The difference in wall thickness between the corner area of ​​the insulating shell and the surrounding area of ​​the insulating shell is less than 25%.

6. The battery module according to claim 4, characterized in that: The projection of the insulating shell in the thickness direction of the battery cell body is a chamfered rectangle, and the insulating shell includes a first shell portion, a second shell portion, and a third shell portion that are sequentially connected along the width direction of the battery cell body; The first shell portion extends from one side of the inner protection portion in the width direction of the battery cell body, along the width direction of the battery cell body, in a direction away from the inner protection portion; The third shell portion extends from the other side of the inner protection portion in the width direction of the battery cell body, along the width direction of the battery cell body, in a direction away from the inner protection portion; The width of the first shell portion in the width direction of the battery cell body is consistent with the width of the third shell portion in the width direction of the battery cell body, and is greater than the wall thickness of the second shell portion.

7. The battery module according to claim 1, characterized in that: The Breaker assembly is a U-shaped structure, the first connector and the first pole ear are attached and bent as a whole in the length direction of the battery body, and the first connector is located on the inner side of the bend; the second connector is located on the side of the second pole ear close to the first pole ear, and a gap is maintained between the second pole ear and the second connector; The insulating shell encloses the first pole lug, the first connecting member, the fuse and part of the second connecting member; The anti-shrinkage port is arranged between the first connecting piece, the fuse and the second connecting piece, and the distances from the anti-shrinkage port to the first connecting piece, the fuse and the second connecting piece are all greater than or equal to the minimum distance required for the hot melt adhesive to flow.

8. The battery module according to claim 7, characterized in that: The second connecting member is bent in the width direction of the battery body so that the bent section of the second connecting member is located on a side of the first connecting member away from the first pole lug and the other section of the second connecting member is located on a side away from the second pole lug; The insulating shell encloses the first pole lug, the first connecting member, the fuse, a portion of the second connecting member and a portion of the second pole lug; The anti-shrinkage port is arranged between the second connecting piece, the fuse and the second pole ear, and the distances from the anti-shrinkage port to the second connecting piece, the fuse and the second pole ear are all greater than or equal to the minimum distance required for the hot melt adhesive to flow.

9. A method for preparing a battery module, characterized in that: include: Take a cell body, one end of which is provided with a tab group, the tab group comprising a first tab and a second tab arranged opposite to each other, and a first insulating adhesive paper is provided on one side of the cell body close to the tab group; Take a Breaker assembly, which is a U-shaped structure, and set the Breaker assembly between the first pole lug and the second pole lug. The Breaker assembly includes a fuse, a first connector and a second connector arranged at both ends of the fuse, and weld the free end of the first connector and the free end of the first pole lug; bending the first connecting member and the first tab along the length direction of the first connecting member; An injection-molded insulating shell is provided at one end of the Breaker assembly on the battery body, and the insulating shell wraps the first pole ear, the first connector, the fuse and part of the second connector; and the outer corner area on the insulating shell has a smooth transition; The wall thickness of the insulating shell is h1, and the value range of h1 is 0.4 mm-4.5 mm.

10. A method for preparing a battery module, characterized in that: include: Take a cell body, one end of which is provided with a tab group, the tab group includes a first tab and a second tab, and a first insulating adhesive paper is provided on one side of the cell body close to the tab group; Take a Breaker assembly, the Breaker assembly is a return-to-original structure, the Breaker assembly includes a fuse, a first connector and a second connector provided at both ends of the fuse, the free end of the first connector and the free end of the first pole ear are welded, and the second connector extends to the outside of the battery body along the length direction of the battery body; bending the first connecting member and the first tab along the length direction of the first connecting member; bending the second connection along the extension direction of the second connection member so that the second connection is bent back; An injection-molded insulating shell is arranged at one end of the breaker assembly on the battery body, and the insulating shell wraps the first pole ear, the first connecting piece, the fuse, part of the second connecting piece and part of the second pole ear; and the outer corner area on the insulating shell has a smooth transition; The wall thickness of the insulating shell is h1, and the value range of h1 is 0.4 mm-4.5 mm.

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