Battery module, battery pack, device using battery module as power source, and method for manufacturing battery module

Abstract

A battery module, a battery pack, an apparatus using the battery module as a power source, and a method of manufacturing the battery module are provided. The battery module comprises: at least two battery cells (10); the connecting sheet (20) is used for electrically connecting the two battery monomers (10); the protective layer (30) comprises a first protective part (31), the first protective part (31) is used for covering the connecting piece (20), and the melting point of the first protective part (31) is larger than that of the connecting piece (20).

Description

[0001] This application is a divisional application of the patent application with international application number PCT / CN2020 / 088877, international application date May 7, 2020, national application number "202080005465.X", date of entry into the Chinese national phase March 31, 2021, and invention name "Battery module, battery pack, device using battery module as power source, and method for manufacturing battery module". Technical Field

[0002] The present disclosure relates to the field of battery technology, and in particular to a battery module, a battery pack, a device using the battery module as a power source, and a method for manufacturing the battery module. Background Art

[0003] The battery module has a plurality of battery cells electrically connected to each other, and two battery cells are electrically connected together through a connecting sheet. During the use of the battery module, sometimes the thermal runaway of one of the battery cells may cause the thermal runaway of the entire battery module. Summary of the invention

[0004] A first aspect of the present disclosure provides a battery module, comprising:

[0005] At least two battery cells;

[0006] A connecting piece, used for electrically connecting two of the battery cells; and

[0007] The protective layer comprises a first protective portion, wherein the first protective portion is used to cover the connecting piece, and the melting point of the first protective portion is greater than the melting point of the connecting piece.

[0008] In the battery module of some embodiments, the first protection portion includes:

[0009] A first upper protection portion, used to cover an upper surface of the connecting sheet away from the battery cell; and

[0010] The first lower protection portion is arranged opposite to the first upper protection portion and is used to cover the lower surface of the connecting sheet close to the battery cell.

[0011] In the battery module of some embodiments, the first protection portion further includes a first side protection portion, and the first side protection portion is used to cover the outer surface of the connecting piece between the upper surface and the lower surface thereof.

[0012] In the battery module of some embodiments, the first side guarding portion is connected to at least one of the first upper guarding portion or the first lower guarding portion.

[0013] In the battery module of some embodiments, the first protective portion is in contact with the connecting sheet.

[0014] In the battery module of some embodiments, the first protection portion is bonded to the connecting sheet.

[0015] In the battery module of some embodiments, the first protection portion is made of an insulating material having a melting point greater than or equal to 660°C.

[0016] In the battery module of some embodiments, the battery module further comprises a circuit board, wherein the circuit board is electrically connected to the battery cell;

[0017] The protection layer further includes a second protection portion, and the second protection portion is used for covering the circuit board.

[0018] In the battery module of some embodiments, the second guarding portion is made of the same material as the first guarding portion.

[0019] In the battery module of some embodiments, the second guarding portion is connected to the first guarding portion.

[0020] In the battery module of some embodiments, the second protection portion includes:

[0021] A second upper protection portion, used to cover an upper surface of the circuit board away from the battery cell; and

[0022] The second lower protection portion is arranged opposite to the second upper protection portion and is used to cover the lower surface of the circuit board close to the battery cell.

[0023] In the battery module of some embodiments, the battery module further includes an output electrode, the output electrode is used to lead out the electrical energy of the battery module, and a first end of the output electrode is electrically connected to the battery cell; and,

[0024] The protection layer further includes a third protection portion, and the third protection portion is used to cover the first end of the output pole.

[0025] In the battery module of some embodiments, the third guarding portion is made of the same material as the first guarding portion.

[0026] In the battery module of some embodiments, the third guarding portion is connected to the first guarding portion.

[0027] In the battery module of some embodiments, the third protection portion includes:

[0028] A third upper protection portion, used to cover an upper surface of the first end of the output electrode away from the battery cell; and

[0029] The third lower protection portion is arranged opposite to the third upper protection portion and is used to cover the lower surface of the first end of the output pole close to the battery cell.

[0030] In the battery module of some embodiments, the third protection portion further includes a second side protection portion, and the second side protection portion is used to cover the outer surface of the first end of the output pole located between the upper surface and the lower surface thereof.

[0031] In the battery module of some embodiments, the battery module further includes a fixing layer, which is disposed outside the protective layer and the connecting sheet and is used to fix the protective layer and the connecting sheet into a whole.

[0032] In the battery module of some embodiments, the fixing layer includes:

[0033] an upper fixing layer, disposed above the connecting sheet and the protective layer; and

[0034] The lower fixing layer is arranged below the connecting piece and the protective layer.

[0035] In the battery module of some embodiments, the upper fixing layer and the lower fixing layer are sealed and connected.

[0036] A second aspect of the present disclosure provides a battery pack, comprising the battery module described in the first aspect of the present disclosure.

[0037] A third aspect of the present disclosure provides a device using a battery module as a power source, comprising the battery module described in the first aspect of the present disclosure.

[0038] A fourth aspect of the present disclosure provides a method for manufacturing a battery module, comprising:

[0039] providing at least two battery cells;

[0040] Providing a connecting piece so that the connecting piece electrically connects the two battery cells; and

[0041] A protective layer is provided, wherein the protective layer is configured to include a first protective portion, and the melting point of the first protective portion is greater than the melting point of the connecting piece, so that the first protective portion covers the connecting piece. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The drawings described herein are used to provide a further understanding of the present disclosure and constitute a part of the present disclosure. The illustrative embodiments of the present disclosure and their descriptions are used to explain the present disclosure and do not constitute an improper limitation on the present disclosure. In the drawings:

[0043] Figure 1 A schematic diagram of the structure of a device using a battery module as a power source according to an embodiment of the present disclosure;

[0044] Figure 2 It is a schematic structural diagram of a battery pack according to an embodiment of the present disclosure;

[0045] Figure 3 This is a schematic structural diagram of a battery module according to an embodiment of the present disclosure;

[0046] Figure 4 for Figure 3 The schematic diagram of the exploded structure of the battery module shown;

[0047] Figure 5 for Figure 3 A schematic structural diagram of a busbar assembly of a battery module shown;

[0048] Figure 6 for Figure 5 The exploded structural diagram of the busbar assembly shown;

[0049] Figure 7 for Figure 6 The enlarged structural diagram of the C portion of the busbar assembly shown;

[0050] Figure 8 for Figure 6 The enlarged structural diagram of the D portion of the busbar assembly is shown. DETAILED DESCRIPTION

[0051] The following will be combined with the drawings in the embodiments of the present disclosure to clearly and completely describe the technical solutions in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present disclosure and its application or use. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0052] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, numerical expressions and numerical values ​​do not limit the scope of the present disclosure. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The technology, methods and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0053] In the description of the present disclosure, it should be understood that the use of words such as "first" and "second" to limit components or physical quantities is merely to facilitate the distinction between corresponding components or physical quantities. Unless otherwise stated, the above words have no special meaning and therefore cannot be understood as limiting the scope of protection of the present disclosure.

[0054] In the description of the present disclosure, it is necessary to understand that the orientation or positional relationship indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present disclosure and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the scope of protection of the present disclosure; the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0055] Embodiments of the present disclosure provide a battery module, a battery pack, a device using the battery module as a power source, and a method for manufacturing the battery module.

[0056] The device using the battery module as a power source includes the battery module of the present disclosure, and the device may be, for example, a vehicle, a ship, an energy storage device, etc. Figure 1 It is a schematic diagram of the structure of a device using a battery module as a power source according to an embodiment of the present disclosure, wherein the device is specifically a vehicle 1.

[0057] The battery pack includes a battery pack housing and a battery module disposed in the battery pack housing. The battery module is the battery module disclosed in the present invention. The battery modules of the battery pack may be one group or multiple groups. Figure 2 The structure diagram of the battery pack 2 of an embodiment of the present disclosure is shown in FIG. 2 , wherein the housing of the battery pack 2 includes an upper housing 2A and a lower housing 2B, and the battery module is located in the housing space of the housing. The battery pack of the embodiment of the present disclosure and the device using the battery module as a power source have the advantages of the battery module of the embodiment of the present disclosure.

[0058] The structure and advantages of the battery module of the embodiment of the present disclosure will be described in the following.

[0059] In the process of implementing the present disclosure, the inventors discovered that when one of the battery cells in a battery module experiences thermal runaway, the flame emitted from the battery cell may melt the connecting piece used to electrically connect the two battery cells. The metal particles ejected when the connecting piece melts may cause an external short circuit in the remaining battery cells, thereby causing the battery cell that has experienced the external short circuit to experience thermal runaway, resulting in a chain reaction, thereby causing the entire battery module to experience thermal runaway.

[0060] In order to reduce the thermal runaway of battery modules, Figures 2 to 8As shown, the battery module of the embodiment of the present disclosure includes more than two battery cells 10, a connecting sheet 20 ( Figure 2 The connecting piece 20 is covered by the protective layer 30, not shown) and the protective layer 30. The connecting piece 20 is used to electrically connect two battery cells 10. The protective layer 30 includes a first protective portion 31, the first protective portion 31 is used to cover the connecting piece 20, and the melting point of the first protective portion 31 is greater than the melting point of the connecting piece 20. The connecting piece 20 is made of metal, such as aluminum, copper or nickel.

[0061] Covering the connecting piece 20 with the first protective portion 31 and having a melting point greater than that of the connecting piece 20 is beneficial to preventing the connecting piece 20 from being melted by high temperature, and is also beneficial to preventing the connecting piece 20 from contacting the metal particles ejected from the battery cell 10 in thermal runaway, thereby preventing the battery cell 10 from short-circuiting, and further preventing the battery module from generating a chain reaction of thermal runaway, thereby improving the safety performance of the battery module and the battery pack including the battery module.

[0062] like Figure 4 and Figure 6 As shown, in the battery module of some embodiments, the first protection portion 31 includes a first upper protection portion 311 and a first lower protection portion 312. The first upper protection portion 311 is used to cover the upper surface of the connecting piece 20 away from the battery cell 10. The first lower protection portion 312 is arranged opposite to the first upper protection portion 311, and is used to cover the lower surface of the connecting piece 20 close to the battery cell 10.

[0063] The first protection portion 31 includes a first upper protection portion 311 and a first lower protection portion 312 , which facilitates the protection layer 30 to fully cover the connecting piece 20 , thereby facilitating the protection layer 30 to provide a protective effect on the connecting piece 20 .

[0064] like Figure 4 , Figure 6 and Figure 7 As shown, in the battery module of some embodiments, the first protection portion 31 further includes a first side protection portion 313 , and the first side protection portion 313 is used to cover the outer surface of the connection sheet 20 between the upper surface and the lower surface thereof.

[0065] The first protection portion 31 includes a first side protection portion 313 , which is beneficial for the protection layer 30 to fully cover the connecting piece 20 , thereby facilitating the protection layer 30 to provide a protective effect on the connecting piece 20 .

[0066] In the battery module of some embodiments, the first side protection portion 313 is connected to the first upper protection portion 311 and / or the first lower protection portion 312. This arrangement facilitates the production of the protection layer 30 and also facilitates the assembly of the protection layer 30 with other components of the battery module.

[0067] In the battery module of some embodiments, the first protective portion 31 is fitted with the connecting sheet 20. The fitting of the first protective portion 31 with the connecting sheet 20 is conducive to reducing the distance between the first protective portion 31 and the connecting sheet 20, thereby reducing the space occupied by both and improving the energy density of the battery module. At the same time, the fitting of the first protective portion 31 with the connecting sheet 20 is conducive to limiting the connecting sheet 20 to maintain its original shape at a high temperature, thereby also facilitating the first protective portion 31 to better protect the connecting sheet 20 covered by it.

[0068] In the battery module of some embodiments, the first protective part 31 is bonded to the connecting sheet 20. The bonding of the first protective part 31 to the connecting sheet 20 facilitates the fixing of the first protective part 31 relative to the connecting sheet 20, which helps prevent the first protective part 31 from being separated from or displaced from the connecting sheet 20, thereby facilitating the first protective part 31 to stably play a protective role.

[0069] In the battery module of some embodiments, the first protective part 31 is made of an insulating material with a melting point greater than or equal to 660°C. For example, the first protective part 31 can be made of mica paper, mica sheet or ceramic material. These materials are all materials with good heat resistance and insulation properties. The first protective part 31 can play the role of heat resistance and insulation at the same time, which is beneficial to prevent the connecting piece 20 from being melted by high temperature, and also to prevent the connecting piece 20 from contacting with the metal particles ejected from the battery cell 10 in thermal runaway, which is beneficial to prevent the battery cell 10 from short circuiting, so that the first protective part 31 can play a better protective role.

[0070] like Figure 4 and Figure 6 As shown, in the battery module of some embodiments, the battery module further includes a circuit board 40, and the circuit board 40 is electrically connected to the battery cell 10. The protective layer 30 further includes a second protective portion 32, and the second protective portion 32 is used to cover the circuit board 40. The protective layer 30 is provided with the second protective portion 32 covering the circuit board 40, which is beneficial to prevent the circuit board 40 from being burned after the battery module has thermal runaway, so that the sampling function is invalid, thereby facilitating the battery management system of the battery pack to issue an alarm signal in time when a battery module fails according to the sampling data transmitted by the circuit board.

[0071] In the battery module of some embodiments, the second protection part 32 is made of the same material as the first protection part 31. This arrangement facilitates the production of the first protection part 31 and the second protection part 32 of the protection layer 30, and also facilitates ensuring the protection effect on the circuit board 40.

[0072] like Figure 4 and Figure 6 As shown, in the battery module of some embodiments, the second protection part 32 is connected to the first protection part 31. This arrangement is conducive to the production of the protection layer 30, and is also conducive to the assembly of the protection layer 30 with other components of the battery module.

[0073] like Figure 4 and Figure 6 As shown, in the battery module of some embodiments, the second protection portion 32 includes a second upper protection portion 321 and a second lower protection portion 322. The second upper protection portion 321 is used to cover the upper surface of the circuit board 40 away from the battery cell 10. The second lower protection portion 322 is arranged opposite to the second upper protection portion 321, and is used to cover the lower surface of the circuit board 40 close to the battery cell 10.

[0074] The second protection portion 32 includes a second upper protection portion 321 and a second lower protection portion 322 , which is beneficial for fully covering the circuit board 40 and for achieving the protection effect of the second protection portion 32 on the circuit board 40 .

[0075] like Figure 4 , Figure 6 and Figure 8 As shown, in some embodiments of the battery module, the battery module further includes an output electrode, the output electrode is used to lead out the electrical energy of the battery module 10, and the first end of the output electrode is electrically connected to the battery cell 10. The protective layer 30 further includes a third protective portion 33, and the third protective portion 33 is used to cover the first end of the output electrode. Figure 4 , Figure 6 and Figure 8 As shown, the battery module includes two output electrodes, a positive output electrode 61 and a negative output electrode 62. The first end 61A of the positive output electrode 61 and the first end 62A of the negative output electrode 62 are used to be electrically connected to the battery cell 10.

[0076] The protection layer 30 includes a third protection portion 33 for covering the first end of the output electrode, which is beneficial to preventing the output electrode from burning or short-circuiting, and is beneficial to improving the safety performance of the battery module or the battery pack including the battery module.

[0077] In the battery module of some embodiments, the third protection part 33 is made of the same material as the first protection part 31. This arrangement is beneficial to the production of each protection part of the protection layer 30 and is also beneficial to ensuring the protection effect on the output pole.

[0078] In the battery module of some embodiments, the third protection part 33 is connected to the first protection part 31. This arrangement is beneficial to the production of the protection layer 30 and also to the assembly of the protection layer 30 with other components of the battery module.

[0079] In the battery module of some embodiments, the third protection part 33 includes a third upper protection part 331 and a third lower protection part 332. The third upper protection part 331 is used to cover the upper surface of the first end of the output pole away from the battery cell 10. The third lower protection part 332 is arranged opposite to the third upper protection part 331, and is used to cover the lower surface of the first end of the output pole close to the battery cell 10.

[0080] The third protection part 33 includes a third upper protection part 331 and a third lower protection part 332 , which is beneficial to fully cover the first end of the output pole and to achieve the protection effect of the protection layer 30 and its third protection part 33 on the output pole.

[0081] In the battery module of some embodiments, the third protection portion 33 further includes a second side protection portion 333 , and the second side protection portion 333 is used to cover the outer surface of the first end of the output pole between the upper surface and the lower surface thereof.

[0082] The third protection portion 33 includes a second side protection portion 333 , which is beneficial to fully cover the first end of the output pole, and is beneficial to achieve the protection effect of the protection layer 30 and its third protection portion 33 on the output pole.

[0083] like Figure 4 and Figure 6 As shown, in the battery module of some embodiments, the battery module further includes a fixing layer 50, which is disposed outside the protective layer 30 and the connecting sheet 20 and is used to fix the protective layer 30 and the connecting sheet 20 as a whole.

[0084] The fixing layer 50 can play a protective role on the one hand, and can also better fix the protection layer 30 to the connecting sheet 20 on the other hand.

[0085] In the battery module of some embodiments, the fixing layer 50 includes an upper fixing layer 50A and a lower fixing layer 50B. The upper fixing layer 50A is disposed above the connecting sheet 20 and the protective layer 30. The lower fixing layer 50B is disposed below the connecting sheet 20 and the protective layer 30.

[0086] The fixing layer 50 includes an upper fixing layer 50A and a lower fixing layer 50B, which facilitates the fixing layer 50 to fix the protective layers 30 on the upper and lower sides of the connecting piece respectively, thereby better playing the role of fixing and protecting.

[0087] In the battery module of some embodiments, the upper fixing layer 50A and the lower fixing layer 50B are sealed and connected. For example, the upper fixing layer 50A and the lower fixing layer 50B can be sealed and connected by a hot pressing process, and the protective layer 30 is attached to the connecting sheet 20 and the fixing layer 50 is arranged outside the protective layer 30. This arrangement can simplify the processing technology, and the hot pressing process can simultaneously complete the shaping of the protective layer 30 and the fixing layer 50, and the positioning and relative fixation of the protective layer 30 and the fixing layer 50 and the components to be protected.

[0088] The fixing layer 50 can be made of a polymer material with insulating properties. The fixing layer 50 made of an insulating polymer material can enhance the insulating properties of the conductive components covered by the fixing layer 50, such as the connecting piece 20. In addition, the upper fixing layer 50A and the lower fixing layer 50B are sealed and connected and made of the aforementioned insulating polymer material, which can also play a waterproof role.

[0089] The embodiment of the present disclosure also provides a method for manufacturing a battery module, including: providing more than two battery cells 10; providing a connecting piece 20 so that the connecting piece 20 electrically connects the two battery cells 10; and providing a protective layer 30, wherein the protective layer 30 is configured to include a first protective portion 31, and the melting point of the first protective portion 31 is greater than the melting point of the connecting piece 20, so that the first protective portion 31 covers the connecting piece 20.

[0090] The manufacturing method does not limit the order of the steps. For example, the protective layer 30 and the connecting sheet 20 can be assembled before the connecting sheet 20 and the battery cell 10 are assembled, or after the connecting sheet 20 and the battery cell 10 are assembled.

[0091] The manufacturing method of the battery module of the embodiment of the present disclosure has the same advantages as the battery module of the embodiment of the present disclosure.

[0092] The following combination Figures 2 to 8 The battery modules of some embodiments of the present disclosure are further described.

[0093] like Figure 2 As shown, in some embodiments, the battery module of the battery pack includes a plurality of battery cells 10, a connecting sheet ( Figure 2 The middle connecting piece is covered by the protective layer 30, not shown) and the protective layer 30. The connecting piece is used to electrically connect two battery cells 10. The protective layer 30 includes a first protective portion 31, which is used to cover the connecting piece 20, and the melting point of the first protective portion 31 is greater than the melting point of the connecting piece 20.

[0094] Figures 3 to 8 The structure of a battery module according to another embodiment of the present disclosure is shown. Figures 3 to 8 In the description of the illustrated embodiment, the thickness direction of the circuit board 40 and the connecting sheet 20 refers to Figures 3 to 6 The z-coordinate direction in Figures 3 to 6 The length direction of the circuit board 40 and the connecting piece 20 refers to Figures 3 to 6 The x-coordinate direction in Figures 3 to 6 The width direction of the circuit board 40 and the connecting piece 20 refers to Figures 3 to 6 The y-coordinate direction in Figures 3 to 6 Middle front and back direction.

[0095] like Figures 3 to 6 As shown, the battery module provided by the embodiment of the present disclosure includes a plurality of battery cells 10 and a busbar assembly. The busbar assembly includes a circuit board 40, a connecting piece 20 electrically connected to the circuit board 40 and an output pole, a protective layer 30 and a fixing layer 50.

[0096] The connecting piece 20 is used to electrically connect the two battery cells 10 of the battery module. The first end of the output pole is electrically connected to the pole 11 of the battery cell 10, and the second end of the output pole is used to electrically connect to the outside of the battery module. The battery module includes two output poles, a positive output pole 61 and a negative output pole 62.

[0097] like Figures 3 to 6 As shown, the protection layer 30 is used to cover the connecting piece 20 , the circuit board 40 , the first end 61A of the positive output electrode 61 , and the first end 62A of the negative output electrode 62 .

[0098] The protective layer 30 is made of a material having a melting point greater than that of the connecting piece 20. For example, the material of the protective layer 30 may be an insulating material having a melting point greater than or equal to 660° C. The protective layer 30 may be made of mica paper, mica sheet or ceramic material.

[0099] The protective layer 30 made of heat-resistant insulating material covering the connecting piece 20 is conducive to preventing the connecting piece 20 from being melted by high temperature, and also isolates the connecting piece 20 from the metal particles ejected by the thermal runaway battery cell 10, which is conducive to preventing the battery cell 10 from short-circuiting, thereby preventing the battery module from producing a chain thermal runaway reaction, and improving the safety performance of the battery module and the battery pack. The protective layer 30 covers the circuit board 40, which is conducive to preventing the sampling function of the circuit board 40 from failing after the battery module has thermal runaway, thereby facilitating the battery management system to send an alarm signal in time when the battery module fails according to the sampling data transmitted by the circuit board. The protective layer 30 covers the first end of the output pole, which is conducive to preventing the output pole from being burned or short-circuited, and is conducive to improving the safety performance of the battery module or the battery pack including the battery module.

[0100] like Figure 3 and Figure 6 As shown, the protection layer 30 includes a first protection portion 31 for covering the connection sheet 20 , a second protection portion 32 for covering the circuit board 40 , and a third protection portion 33 for covering the first ends of the positive output electrode 61 and the negative output electrode 62 .

[0101] like Figure 6 and Figure 7 As shown, the first protection part 31 includes a first upper protection part 311, a first lower protection part 312 and a first side protection part 313. The first upper protection part 311 is used to cover the upper surface of the connecting piece 20 away from the battery cell 10. The first lower protection part 312 is arranged opposite to the first upper protection part 311, and is used to cover the lower surface of the connecting piece 20 close to the battery cell 10. The first side protection part 313 is used to cover the outer surface of the connecting piece 20 located between its upper surface and lower surface. The first side protection part 313 is connected to the first upper protection part 311. The first protection part 31 is in contact with the connecting piece 20.

[0102] like Figure 6As shown, the second protection part 32 includes a second upper protection part 321 and a second lower protection part 322. The second upper protection part 321 is used to cover the upper surface of the circuit board 40 away from the battery cell 10. The second lower protection part 322 is arranged opposite to the second upper protection part 321, and is used to cover the lower surface of the circuit board 40 close to the battery cell 10. The second protection part 32 is attached to the circuit board 30.

[0103] The third protection part 33 includes a third upper protection part 331, a third lower protection part 332 and a second side protection part 333. The third upper protection part 331 is used to cover the upper surface of the first end 61A of the positive output pole 61 away from the battery cell 10 and the upper surface of the first end 62A of the negative output pole 62 away from the battery cell 10. The third lower protection part 332 is arranged opposite to the third upper protection part 331, and is used to cover the lower surface of the first end 61A of the positive output pole 61 close to the battery cell 10 and the lower surface of the first end 62A of the negative output pole 62 close to the battery cell 10. The second side protection part 333 is used to cover the outer surface of the first end 61A of the positive output pole 61 located between its upper surface and lower surface and the outer surface of the first end 62A of the negative output pole 62 located between its upper surface and lower surface. The second side protection part 333 is connected to the third upper protection part 331. The third protection part 33 is attached to the first ends of the two output poles.

[0104] The first protection part 31, the second protection part 32 and the third protection part 33 are all made of mica paper. The first protection part 31, the second protection part 32 and the third protection part 33 are connected to each other.

[0105] The thickness and structure of the protective layer 30 can be adjusted according to the material of the protective layer 30 and the actual use requirements of the battery module.

[0106] like Figure 4 and Figure 6 As shown, the protective layer 30 includes an upper protective layer 30A and a lower protective layer 30B which are arranged opposite to each other. Figure 3 In the state of being assembled with each battery cell 10, the connection piece 20, the circuit board 40 and the surface of the output pole covered by the protective layer 30 are isolated from each battery cell 10. The upper protective layer 30A and the lower protective layer 30B of the protective layer 30 are respectively covered on both sides of the thickness direction of the connection piece 20, the circuit board 40 and the first end of the output pole as an integral structure. The upper protective layer 30A is located on the upper side of the connection piece 20, the circuit board 40 and the output pole, and the lower protective layer 30B is located on the lower side of the connection piece 20, the circuit board 40 and the first end of the output pole.

[0107] like Figures 6 to 8As shown, the upper protection layer 30A includes the aforementioned first upper protection portion 311, the first side protection portion 312, the second upper protection portion 321, the third upper protection portion 331 and the second side protection portion 333. The first upper protection portion 311, the first side protection portion 312, the second upper protection portion 321, the third upper protection portion 331 and the second side protection portion 333 are formed integrally.

[0108] like Figure 6 As shown, the lower shielding layer 30B includes the aforementioned first lower shielding portion 312, the second lower shielding portion 322 and the third lower shielding portion 332. The first lower shielding portion 312, the second lower shielding portion 322 and the third lower shielding portion 332 are formed integrally.

[0109] like Figure 3 and Figure 4 As shown, the battery module includes a plurality of battery cells 10 arranged in an array. In some embodiments, 12 battery cells 10 are arranged in two rows along the front-to-back direction (Y coordinate direction), and 6 battery cells are arranged in each row along the left-to-right direction (X coordinate direction). The height direction of each battery cell 10 is the up-and-down direction (Z coordinate direction), the length direction is the left-to-right direction, and the width direction is the front-to-back direction. Two poles 11, a positive pole and a negative pole, are provided on each battery cell 10. The connecting piece 20, the circuit board 40 and the first end of the output pole are provided above each battery cell 10. The connecting piece 20, the circuit board 40 and the first end of the output pole are assembled and connected with the corresponding battery cell 10 to connect each battery cell 10 into a battery pack.

[0110] The circuit board 40 is electrically connected to each connecting piece 20, the positive output electrode 61 and the negative output electrode 62. The circuit board 40 may be a FPC (Flexible Printed Circuit). The FPC is mainly composed of a base film, a copper busbar and a heat-resistant protective film, and a signal acquisition terminal is provided at one end of the FPC.

[0111] The connecting piece 20 is usually made of a metal conductive material such as aluminum or copper, and is used to connect different battery cells 10. The positive output electrode 61, the negative output electrode 62 and each connecting piece 20 are provided with an assembly hole, and the connecting piece 20, the positive output electrode 61 and the negative output electrode 62 are welded to the pole 11 of the corresponding battery cell 10 at the position of the assembly hole. The positive output electrode 61 and the negative output electrode 62 are used to realize the electrical connection between the battery module and the outside world. The first end 61A of the positive output electrode 61 and the first end 62A of the negative output electrode 62 are respectively connected to the Figure 4 One pole 11 of the battery cell 10 at the middle right end is electrically connected, and the second end of the positive output pole 61 and the negative output pole 62 serves as the output end of the output pole.

[0112] The positive output electrode 61 and the negative output electrode 62 are both bent into an L shape. The two output electrodes are usually made of metal conductive materials such as aluminum and copper.

[0113] The protective layer 30 is provided with positioning holes corresponding to the positions of the assembly holes or welding avoidance holes for assembling the connecting piece 20, the circuit board 40 and the first end of the output pole, and these positioning holes are used to realize the alignment installation with the connecting piece 20, the circuit board 40 and the first end of the output pole. In this embodiment, the protective layer 30 is made of mica paper.

[0114] exist Figures 3 to 8 In the illustrated embodiment, the protective layer 30 is used to protect the connecting piece 20, the circuit board 40 and the first end of the output pole. Since the protective layer 30 covers the connecting piece 20, it can play the role of protecting the connecting piece 20, which is beneficial to prevent the connecting piece 20 from melting due to heat after the battery module has thermal runaway, thereby triggering a thermal runaway chain reaction. Since the protective layer 30 covers the circuit board 40, the protective layer 30 is also used to protect the circuit board 40, so as to prevent the sampling function of the circuit board 40 from failing after the battery module has thermal runaway. Since the protective layer 30 covers the first end of the output pole, it is also beneficial to prevent the output pole from being damaged or short-circuited after the battery module has thermal runaway.

[0115] like Figures 3 to 6 As shown, positioning holes are provided on both the upper protective layer 30A and the lower protective layer 30B of the protective layer 30 .

[0116] like Figures 3 to 6 As shown, the fixing layer 50 is arranged outside the protective layer 30, the connecting piece 20, the circuit board 40 and the first end of the output pole. The fixing layer 50 can play an insulating and protective role on the one hand, and can also fix the protective layer 30, the connecting piece 20, the circuit board 40 and the output pole into a whole on the other hand.

[0117] The fixing layer 50 may be made of a polymer material having insulating properties, such as PET (Polyethyleneterephthalate), PI (Polyimide), PC (Polycarbonate), PEN (Polyethylene naphthalate), and the like.

[0118] On the one hand, the fixing layer 50 insulates the portion of the busbar assembly covered by the fixing layer 50 from other components of the battery module, and on the other hand, it can fix the protective layer 30 with the connecting piece 20, the circuit board 40 and the output pole to prevent the protective layer 30 from falling off or shifting.

[0119] like Figure 4 and Figure 6As shown, the fixing layer 50 includes an upper fixing layer 50A and a lower fixing layer 50B. The upper fixing layer 50A is located above the upper protective layer 30A; the lower fixing layer 50B is located below the lower protective layer 30B. The upper fixing layer 50A and the lower fixing layer 50B fix the upper protective layer 30A and the lower protective layer 30B to the connecting piece 20, the circuit board 40 and the output pole. The upper fixing layer 50A is adapted to the shape of the upper protective layer 30A. The lower fixing layer 50B is adapted to the shape of the lower protective layer 30B.

[0120] Similar to the protective layer 30, the fixing layer 50 is provided with positioning holes corresponding to the positions of the assembly holes or welding avoidance holes of the connecting piece 20, the circuit board 40 and the first end of the output pole, and these positioning holes are used to realize the alignment assembly with the connecting piece 20, the circuit board 40 and the first end of the output pole. Figures 3 to 6 As shown, positioning holes are provided on both the upper fixing layer 50A and the lower fixing layer 50B of the fixing layer 50 .

[0121] In order to better fix the protective layer 30 and prevent the protective layer 30 from falling off, the protective layer 30 and the fixing layer 50 are formed and fixed by a hot pressing process, and the upper fixing layer 50A and the lower fixing layer 50B are sealed and connected. The hot pressing process can make the upper protective layer 30A and the lower protective layer 30B arranged on the upper and lower sides of the connecting piece 20, the circuit board 40 and the first end of the output pole completely fit on the connecting piece 20, the circuit board 40 and the first end of the output pole according to the contour of the connecting piece 20, the circuit board 40 and the first end of the output pole; on the other hand, the hot pressing process can make the edge parts of the upper fixing layer 50A and the lower fixing layer 50B fixedly connected, so that the connecting piece 20, the circuit board 40, the output pole and the protective layer 30 are arranged in the fixing layer 50.

[0122] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present disclosure rather than to limit it. Although the present disclosure has been described in detail with reference to the preferred embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present disclosure can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the present disclosure, which should be included in the scope of the technical solution for protection of the present disclosure.

Claims

1. A battery module, comprising: at least two battery cells (10); A connecting sheet (20) used for electrically connecting the two battery cells (10); A circuit board (40), the circuit board (40) being electrically connected to the battery cell (10); The protective layer (30) is made of a material having a melting point greater than that of the connecting sheet (20) and forms an upper protective layer (30A) and a lower protective layer (30B), comprising a first protective portion (31) and a second protective portion (32), wherein the first protective portion (31) comprises a first upper protective portion (311) and a first lower protective portion (312), wherein the first upper protective portion (311) covers an upper surface of the connecting sheet (20) away from the battery cell (10), the first lower protective portion (312) is arranged opposite to the first upper protective portion (311) and covers a lower surface of the connecting sheet (20) close to the battery cell (10), and the second protective portion (312) is disposed on the upper surface of the connecting sheet (20) The protective portion (32) comprises a second upper protective portion (321) and a second lower protective portion (322), the second upper protective portion (321) covers an upper surface of the circuit board (40) away from the battery cell (10), and the second lower protective portion (322) is arranged opposite to the second upper protective portion (321) and covers a lower surface of the circuit board (40) close to the battery cell (10), wherein the upper protective layer (30A) comprises the first upper protective portion (311) and the second upper protective portion (321), and the lower protective layer (30B) comprises the first lower protective portion (312) and the second lower protective portion (322); and A fixing layer (50), the fixing layer (50) comprising an upper fixing layer (50A) and a lower fixing layer (50B), the upper fixing layer (50A) being arranged above the upper protective layer (30A), the lower fixing layer (50B) being arranged below the lower protective layer (30B), the upper fixing layer (50A) being sealingly connected to the lower fixing layer (50B), so as to fix the protective layer (30), the connecting sheet (20) and the circuit board (40) as a whole through the fixing layer (50).

2. The battery module according to claim 1, wherein: The first protection portion (31) further comprises a first side protection portion (313), the first side protection portion (313) being used to cover an outer surface of the connecting piece (20) located between its upper surface and lower surface, and the upper protection layer (30A) comprises the first side protection portion (313).

3. The battery module according to claim 1, wherein: The first protection portion (31) is in contact with the connecting sheet (20).

4. The battery module according to claim 1, wherein: The first protection portion (31) is bonded to the connecting sheet (20).

5. The battery module according to claim 1, wherein: The protective layer (30) is made of an insulating material with a melting point greater than or equal to 660°C.

6. The battery module according to any one of claims 1 to 5, wherein: The battery module further comprises an output pole (61, 62), the output pole (61, 62) being used to lead out electrical energy of the battery module (10), the first end (61A, 62A) of the output pole (61, 62) being used to be electrically connected to the battery cell (10); and, The protective layer (30) further comprises a third protective portion (33), the third protective portion (33) being used to cover the first end (61A, 62A) of the output pole (61, 62), the third protective portion (33) comprising a third upper protective portion (331) and a third lower protective portion (332), the third upper protective portion (331) covering the upper surface of the first end (61A, 62A) of the output pole (61, 62) away from the battery cell (10), the third lower protective portion (332) being arranged opposite to the third upper protective portion (331) and covering the lower surface of the first end (61A, 62A) of the output pole (61, 62) close to the battery cell (10), the upper fixing layer (50A) comprising the third upper protective portion (331), and the lower fixing layer (50B) comprising the third lower protective portion (332).

7. The battery module according to claim 6, wherein: The third protection portion (33) further includes a second side protection portion (333), the second side protection portion (333) being used to cover the outer surface of the first end (61A, 62A) of the output pole (61, 62) located between the upper surface and the lower surface thereof, and the upper protection layer (30A) includes the second side protection portion (333).

8. The battery module according to any one of claims 1 to 5, wherein: The protective layer (30) and the fixing layer (50) are formed and fixed by a hot pressing process, and the upper fixing layer (50A) and the lower fixing layer (50B) are sealed and connected.

9. A battery pack comprising the battery module according to any one of claims 1 to 8.

10. A device using a battery module as a power source, the battery module comprising the battery module according to any one of claims 1 to 9.

Images