Battery cell assembly, battery, energy storage system and equipment

Abstract

The embodiment of the utility model provides a battery cell assembly, a battery, an energy storage system and equipment, and belongs to the technical field of batteries, the battery cell assembly comprises a battery cell and an insulating protective shell, the insulating protective shell is of an integrated shell structure with a first opening in one end and an accommodating cavity in the insulating protective shell, and the battery cell can be accommodated and fixed in the accommodating cavity through the first opening; and the battery core assembly can be integrally arranged in the shell to be assembled into the battery. As the insulating protective shell is of an integrally designed shell structure, gaps such as splicing, assembling and bonding do not exist, an insulating protective effect on the battery cell can be effectively achieved, and contact between free electrolyte and the shell is avoided, so that an ion channel is isolated, the electrochemical corrosion problem of the shell is effectively avoided, and the service life of the battery cell is prolonged. And the safety and the reliability of the battery are obviously improved. And the battery cell is inserted into the integrated insulating protective shell to assemble the battery cell assembly, so that the assembly operation mode and difficulty are low, and the assembly efficiency is favorably improved.

Description

Technical Field

[0001] This application relates to the technical field of batteries, and particularly to a battery cell assembly, a battery, an energy storage system and a device. Background Art

[0002] A battery is a component that converts chemical energy into electrical energy and has a very wide range of applications in daily life and work. For example, lithium-ion batteries are often used in various electronic devices such as mobile phones, cameras, electronic watches, Bluetooth headsets, and electric toys to provide power for the electronic devices. With the development of lithium battery technology, the application of lithium batteries in the fields of communication power supplies, data centers, microgrid energy storage, electric vehicles, etc. is also becoming more and more extensive.

[0003] A battery usually includes a casing and a battery cell. The battery cell is placed inside the casing, and an electrolyte is injected into the battery cell. The casing is mostly a rigid casing with one end open. During the battery manufacturing process, the battery cell needs to be loaded into the rigid casing through this opening to complete the assembly. Usually, the battery cell is insulated and protected by wrapping it with a soft Mylar film, preventing damage to the battery cell caused by the aluminum casing, and also being able to reduce the chemical corrosion of the casing caused by the free electrolyte leaking out of the battery cell. The Mylar film is a soft and flexible sheet-like film, cut into a shape that can wrap the battery cell, such as a first covering piece corresponding to the bottom surface of the battery cell and a second covering piece corresponding to the side surface of the battery cell, and then the battery cell is wrapped respectively, and the first covering piece is bonded and spliced with the second covering piece, and the two sides of the second covering piece are bonded and spliced, so as to completely wrap the battery cell.

[0004] However, the electrolyte is easy to flow through the splicing or bonding gaps, and cannot effectively block the contact between the free electrolyte and the casing, and there is still a problem of electrochemical corrosion of the casing. Summary of the Utility Model

[0005] The embodiments of this application provide a battery cell assembly, a battery, an energy storage system and a device, which effectively prevent the contact between the free electrolyte and the casing and avoid the problem of electrochemical corrosion.

[0006] In the first aspect of the embodiments of this application, a battery cell assembly is provided, including a battery cell and an insulating protective casing. The insulating protective casing is an integral casing structure with a first opening at one end and an accommodation cavity inside. The first opening is used for the battery cell to pass through and be fixed inside the accommodation cavity. That is, the battery cell can pass through the first opening and be accommodated and fixed inside the accommodation cavity of the insulating protective casing. The insulating protective casing plays an insulating and protective role for the battery cell. On the one hand, the insulating protective casing can reduce the damage to the battery cell caused by the casing during the battery assembly process. On the other hand, the insulating protective casing can play an insulating isolation role between the battery cell and the casing, avoiding the chemical corrosion of the casing caused by the free electrolyte leaking out of the battery cell.

[0007] The insulating protective shell is an integrated shell structure, and the battery cell is placed inside the insulating protective shell. Compared with the related technology where a mylar film is wrapped around the battery cell, the integrated insulating protective shell has no gaps such as splicing, assembling, and bonding, and can effectively insulate and protect the battery cell, effectively isolating the contact between the free electrolyte and the outer shell, thereby isolating the ion channel and avoiding the problem of electrochemical corrosion of the outer shell. Even in the scenario where the negative electrode structure contacts the outer shell to form an electron channel, it will not cause electrochemical corrosion to the outer shell, significantly improving the safety and reliability of the battery.

[0008] In addition, inserting the battery cell into the insulating protective shell through the first opening to assemble the battery cell assembly is simpler and has a lower operation difficulty compared to wrapping a mylar film around the battery cell and splicing and bonding the mylar film, which is beneficial to improving the assembly efficiency.

[0009] In a possible implementation manner, the battery cell assembly further includes a top cover, the top cover is fixed on the top end face of the battery cell, the top cover is fixed to the end of the insulating protective shell with the first opening, and the top cover covers the first opening. The accommodating cavity of the insulating protective shell can be closed through the top cover, so that the battery cell is located in the closed accommodating cavity, further improving the insulation and protection of the battery cell. Moreover, the battery cell can be fixed through the top cover to prevent the battery cell from falling during transportation or use.

[0010] In a possible implementation manner, the insulating protective shell includes a bottom shell and a side shell surrounding the bottom shell. The bottom shell and the side shell enclose an accommodating cavity with a first opening at one end. The bottom shell and the side shell are of an integrated structure, and the top cover is fixed to the end of the side shell facing away from the bottom shell. The insulating protective shell is an integrated shell structure formed by the bottom shell and the side shell, with a simple structural design and easy to be formed and realized.

[0011] In a possible implementation manner, there is a groove on the surface of the side shell facing away from the accommodating cavity. When the insulating protective shell containing the battery cell is inserted into the inner cavity of the outer shell, the groove on the side shell can form an exhaust channel, enabling the air in the outer shell cavity to be discharged through the groove, reducing or avoiding the air pressure obstruction during the insertion process, and making it more convenient to insert the battery cell assembly into the outer shell, improving the convenience of assembly.

[0012] In a possible implementation manner, the thicknesses of the bottom shell and the side shell are respectively 0.02 mm to 0.5 mm. It can reduce or avoid the influence on the energy density, ensure the electrical performance, and is easy to form the integrated insulating protective shell, which is beneficial to reducing the forming and processing difficulty.

[0013] In a possible implementation manner, the thicknesses of the bottom shell and the side shell are respectively 0.05 mm to 0.2 mm, with less influence on the energy density and better processability.

[0014] In a possible implementation, the side housing includes a first housing, a second housing, a third housing, and a fourth housing. The first housing and the second housing are opposite to each other in the width direction, the third housing and the fourth housing are opposite to each other in the length direction, and the first housing, the second housing, the third housing, and the fourth housing enclose a square-ring-shaped side housing.

[0015] Two end faces of the first housing opposite to each other in the length direction are respectively attached and joined to one end face of the third housing in the width direction and one end face of the fourth housing in the width direction, that is, the first housing is sequentially attached and joined to the third housing and the fourth housing end faces, and there is no overlapping area in the width direction or the length direction.

[0016] Two end faces of the second housing opposite to each other in the length direction are respectively attached and joined to the other end face of the third housing in the width direction and the other end face of the fourth housing in the width direction, that is, the second housing is sequentially attached and joined to the third housing and the fourth housing end faces, and there is also no overlapping area in the width direction or the length direction. This improves the thickness consistency of each surface of the side housing, thereby reducing or avoiding the impact on the energy density distribution due to excessive thickness difference.

[0017] In a possible implementation, the length of the first housing is respectively greater than the widths of the third housing and the fourth housing, and the length of the second housing is respectively greater than the widths of the third housing and the fourth housing, so that the side housing can be a rectangular ring structure, and the formed insulation protection shell can be a cuboid structure with one end open, which can be used to accommodate a square battery cell and has wide applicability.

[0018] In a possible implementation, the thickness of the bottom housing is respectively 50% - 200% of the thicknesses of the first housing and the second housing, which not only reduces the impact on the energy density, ensures the electrical performance, but also has good processability.

[0019] In a possible implementation, the thickness of the third housing is respectively 50% - 200% of the thicknesses of the first housing and the second housing, and the thickness of the fourth housing is respectively 50% - 200% of the thicknesses of the first housing and the second housing, which can also achieve the effect of reducing the impact on the energy density and having good processability.

[0020] In a possible implementation, the ratio of the inner surface length of the insulation protection shell to the outer surface length of the battery cell is 1.0 - 1.15, which is convenient for the battery cell to enter the accommodation cavity of the insulation protection shell and facilitates assembly.

[0021] In a possible implementation, the ratio of the inner surface length of the insulation protection shell to the outer surface length of the battery cell is 1.0 - 1.1, which enables the battery cell to enter the insulation protection shell more conveniently and has high assembly feasibility.

[0022] In a possible implementation, the ratio of the inner surface width of the insulation protective shell to the outer surface width of the battery cell is 1.0 to 1.15, which can also facilitate the battery cell to enter the accommodation cavity of the insulation protective shell and is convenient for assembly.

[0023] In a possible implementation, the ratio of the inner surface width of the insulation protective shell to the outer surface width of the battery cell is 1.0 to 1.1, which enables the battery cell to enter the insulation protective shell more conveniently and has high assembly feasibility.

[0024] In a possible implementation, the depth of the groove is 0.01 mm to 5 mm. Under the condition that the setting of the groove has little influence on the accommodation capacity of the inner accommodation cavity of the insulation protective shell, the exhaust effect of the groove is ensured and the assembly convenience is guaranteed.

[0025] In a possible implementation, the depth of the groove is 0.01 mm to 2 mm, which has little influence on the capacity of the accommodation cavity, has a good exhaust effect, and has higher assembly convenience.

[0026] In a possible implementation, a plastic layer is provided on the surface of the top cover facing the insulation protective shell, and the top cover is fixed to the insulation protective shell through the plastic layer. For example, the plastic layer on the top cover can be fixed to the insulation protective shell by heat sealing. The assembly design is simple and has high bonding strength.

[0027] In a possible implementation, the material of the insulation protective shell includes one or more of polyethylene terephthalate, polypropylene, polyethylene, and polytetrafluoroethylene, which has good electrolyte corrosion resistance and is beneficial to further improving the safety and stability of the battery.

[0028] In the second aspect of the embodiments of the present application, a battery is provided, which includes a housing and the battery cell assembly as described in any one of the above. The battery cell assembly is accommodated in the housing, and the housing can play an isolation and protection role for the battery cell assembly.

[0029] In a possible implementation, one end of the housing has a second opening, and the second opening is used for the battery cell assembly to pass through and be fixed inside the housing. The top cover of the battery cell assembly is fixed to the end of the housing having the second opening, and the top cover covers the second opening. The cavity inside the housing can also be closed through the top cover, further ensuring that the battery cell is located in a closed space and playing a better insulation and protection role for the battery cell.

[0030] In a possible implementation, the ratio of the outer surface length of the insulation protective shell to the inner surface length of the housing is 0.9 to 1.0, which facilitates the insulation protective shell containing the battery cell to enter the cavity of the housing and is convenient for assembly.

[0031] In a possible implementation, the ratio of the outer surface length of the insulation protection shell to the inner surface length of the outer shell is 0.95 to 0.99, enabling the battery cell to enter the insulation protection shell more conveniently and with high assembly feasibility.

[0032] In a possible implementation, the ratio of the outer surface width of the insulation protection shell to the inner surface width of the outer shell is 0.9 to 1.0, which can also facilitate the entry of the insulation protection shell containing the battery cell into the cavity of the outer shell, facilitating assembly.

[0033] In a possible implementation, the ratio of the outer surface width of the insulation protection shell to the inner surface width of the outer shell is 0.95 to 0.99, enabling the battery cell to enter the insulation protection shell more conveniently and with high assembly feasibility.

[0034] The third aspect of the embodiments of the present application provides an energy storage system, including a control unit and any one of the above batteries, and the control unit is used to be connected to the battery.

[0035] The fourth aspect of the embodiments of the present application provides a device, including a housing and the above energy storage system, and the energy storage system is assembled on the housing. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic diagram of the framework structure of an energy storage system provided by an embodiment of the present application;

[0037] Figure 2 It is a schematic diagram of the structure of a battery cell assembly provided by an embodiment of the present application;

[0038] Figure 3 It is Figure 2 a schematic diagram of the structure of the insulation protection shell in the battery cell assembly of;

[0039] Figure 4 It is Figure 3 a schematic diagram of the forming process of the insulation protection shell in;

[0040] Figure 5 It is Figure 2 a schematic diagram of a structure during the assembly of the battery cell and the insulation protection shell in the battery cell assembly of;

[0041] Figure 6 It is Figure 2 a schematic diagram of a structure during the assembly of the battery cell assembly and the outer shell in;

[0042] Figure 7 It is Figure 2 a schematic diagram of the structure of the battery formed by the assembly of the battery cell assembly and the outer shell in;

[0043] Figure 8 It is Figure 7 a schematic diagram of the insulation withstand voltage test of the battery in;

[0044] Figure 9 Schematic diagram of the insulation withstand voltage test of a battery with a mylar film wrapping the battery cell in the related art;

[0045] Figure 10 For Figure 2 Another schematic diagram of the insulation protection shell in the battery cell assembly of

[0046] Figure 11 For Figure 7 Schematic diagram of the length dimension of the battery of

[0047] Figure 12 For Figure 7 Schematic diagram of the width dimension of the battery of

[0048] Figure 13 Schematic diagram of another battery cell assembly provided by an embodiment of the present application.

[0049] Description of the reference numerals:

[0050] 100 - Energy storage system;

[0051] 101 - Control unit;

[0052] 102 - Battery;

[0053] 10 - Outer shell;

[0054] 11 - Second opening; 12 - Cavity;

[0055] 20 - Battery cell assembly;

[0056] 21 - Battery cell; 211 - Positive electrode tab; 212 - Negative electrode tab;

[0057] 22 - Insulation protection shell; 22a - First opening; 22b - Accommodating cavity;

[0058] 221 - Bottom shell;

[0059] 222 - Side shell;

[0060] 2221 - First shell; 2222 - Second shell; 2223 - Third shell; 2224 - Fourth shell;

[0061] 2225 - Groove;

[0062] 23 - Top cover;

[0063] 24 - Plastic layer. Detailed implementation manners

[0064] The terms used in the implementation manners part of the present application are only used to explain the specific embodiments of the present application, rather than intended to limit the present application.

[0065] An embodiment of the present application provides an energy storage system, which is a system used to store energy and release the energy when needed. Specifically, the energy storage system is a battery energy storage system, that is, it uses batteries to achieve the purpose of storing electrical energy and can realize the storage and release of electrical energy.

[0066] This energy storage system can be applied to the field of electronic terminal devices. For example, this energy storage system can be applied to electronic devices such as mobile phones, laptop computers, tablet computers, handheld computers, walkie-talkies, netbooks, POS machines, personal digital assistants (PDAs), wearable devices, and vehicle-mounted devices.

[0067] Alternatively, this energy storage system can also be applied to the energy storage of electronic devices such as communication power supplies, data centers, and communication base stations.

[0068] This energy storage system can also be applied to the field of energy storage power stations. For example, it can be applied to microgrid energy storage, etc.

[0069] Alternatively, this energy storage system can also be applied to the energy storage of fields such as electric vehicles.

[0070] Of course, in some other examples, this energy storage system can also be applied to any other fields and devices that need to achieve electrical energy storage.

[0071] Based on this, an embodiment of the present application further provides a device including this energy storage system. The device can include, but is not limited to, electronic devices such as mobile phones, laptop computers, tablet computers, handheld computers, walkie-talkies, netbooks, POS machines, personal digital assistants PDA, wearable devices, and vehicle-mounted devices.

[0072] Alternatively, the device can include, but is not limited to, electronic devices such as data center devices, communication power supply devices, and communication base stations.

[0073] Alternatively, the device can include, but is not limited to, energy storage power station devices. For example, it can be wind energy storage devices, photovoltaic energy storage devices, pumped-storage energy storage devices, etc.

[0074] Alternatively, the device may include, but is not limited to, an electric vehicle (EV), a pure electric vehicle (PEV / BEV), a hybrid electric vehicle (HEV), a range extended electric vehicle (REEV), a plug-in hybrid electric vehicle (PHEV), a new energy vehicle, etc.

[0075] The energy storage system can be assembled on the housing of each of the above devices. Through the energy storage system, charging, power supply, etc. of the device can be achieved to meet the electrical energy requirements for the operation of the device.

[0076] Figure 1 It is a schematic diagram of the frame structure of an energy storage system provided by an embodiment of the present application.

[0077] Among them, the energy storage system 100 may include a battery 102 and a control unit 101. The battery 102 is used to store and release electrical energy.

[0078] The control unit 101 is connected to the battery 102. The control unit 101 can be used to manage the battery 102. For example, the control unit 101 can achieve charge equalization, thermal management, cell state detection and control, etc. of the battery 102, so as to achieve the working control and state monitoring of the battery 102.

[0079] Among them, there may be one battery 102 in the energy storage system 100. Alternatively, the energy storage system 100 may include multiple batteries 102. The multiple batteries 102 can be distributed in a series / parallel manner. The setting of the multiple batteries 102 is beneficial to improving the performance of the energy storage system 100.

[0080] Of course, in some other examples, the energy storage system 100 may further include some other device structures to improve its functions. For example, it may further include a sensing and monitoring structure, a heat dissipation structure, etc.

[0081] Among them, continue to refer to Figure 1 As shown, the battery 102 may include a housing 10 and a cell 21. The housing 10 can be used as the main load-bearing structure of the battery 102, and the cell 21 can be arranged inside the housing 10.

[0082] The battery cell 21 can be used to store and release electrical energy. The battery cell 21 has an exposed positive electrode tab 211 and a negative electrode tab 212. The positive electrode tab 211 and the negative electrode tab 212 can be respectively connected to the positive electrode structure and the negative electrode structure of the battery 102. The battery 102 can be electrically connected to an external device through the positive electrode structure and the negative electrode structure to realize the transmission of current between the battery 102 and the external device.

[0083] The battery 102 may further include an electrolyte (not shown in the figure). The electrolyte can be injected into the battery cell 21. The electrolyte can serve as a carrier for ion transport in the battery cell 21. The electrolyte plays a role in conducting ions between the positive electrode tab 211 and the negative electrode tab 212 of the battery cell 21 to realize the storage and release of electrical energy.

[0084] Of course, in some other examples, the battery 102 may further include other structural components. For example, a sensing and detection structure may be provided inside the housing 10 of the battery 102.

[0085] The battery 102 can be a lithium-ion battery. That is to say, the battery 102 mainly relies on the movement of lithium ions between the positive electrode and the negative electrode to realize the functions of charging and discharging. For example, the battery 102 can include, but is not limited to, lithium iron phosphate batteries, nickel cobalt manganese ternary batteries, lithium cobalt oxide batteries, etc.

[0086] Lithium-ion batteries have a large capacity and a high working voltage, thus having good energy storage performance. Moreover, lithium-ion batteries can allow a wide working range and have a long cycle life.

[0087] In addition, lithium-ion batteries have a fast charging and discharging speed, high safety and reliability. Lithium-ion batteries also do not contain harmful substances such as cadmium, lead, and mercury, and have less impact on the environment.

[0088] Of course, in some other examples, the battery 102 can also be other types of batteries. For example, the battery 102 can also be a sodium-ion battery, etc.

[0089] Taking the lithium-ion battery as an example, currently, lithium-ion batteries mainly have three forms, namely square aluminum shell batteries, cylindrical steel shell batteries, and soft-pack batteries. Among them, square aluminum shell batteries have high safety and stability and are widely used. The housing of the square aluminum shell battery is a cuboid hard aluminum shell structure. One end of the housing has an opening, and there is a cavity inside. When assembling the battery, the battery cell is inserted into the cavity of the housing from the opening.

[0090] To reduce the damage to the battery cells during the assembly process, the battery usually further includes a mylar film. The mylar film can wrap the battery cells to protect them and reduce the damage caused by the outer shell to the battery cells during the battery assembly process. The mylar film can also play an insulating and isolating role between the battery cells and the outer shell, reducing the chemical corrosion of the outer shell caused by the free electrolyte leaking from the battery cells.

[0091] The mylar film is a soft sheet film, which is designed to wrap each outer surface of the battery cells separately in a split manner and then spliced to wrap the entire battery cell (with the tabs exposed). For example, by means of cutting, etc., the sheet mylar film can be made to have regional parts that can correspondingly wrap each surface of the battery cell. For instance, taking the top surface of the battery cell as the side where the positive tab and the negative tab are exposed, the bottom surface of the battery cell is opposite to the top surface, and the side surface of the battery cell is located between the top surface and the bottom surface of the battery cell.

[0092] The mylar film can have a first covering piece corresponding to the bottom surface of the battery cell and a second covering piece corresponding to the side surface of the battery cell. Then, the mylar film is corresponded to the battery cell. The first covering piece wraps the bottom surface of the battery cell, and the second covering piece wraps the side surface of the battery cell. The first covering piece can partially extend to the side surface of the battery cell and at least partially overlap with the second covering piece to be bonded together. The two sides of the second covering piece can also partially overlap and be bonded together. That is, both the first covering piece and the second covering piece, and the two sides of the second covering piece have overlapping areas in the width or length direction to ensure the bonding strength. In this way, the entire battery cell is comprehensively wrapped through the covering and splicing of the first covering piece and the second covering piece.

[0093] However, the free electrolyte will flow through the gaps of the splicing or bonding, unable to effectively block the contact between the electrolyte and the outer shell, posing a risk of electrochemical corrosion to the outer shell and reducing the safety and reliability of the battery.

[0094] Based on this, the embodiment of the present application provides a battery cell assembly, which includes an insulating protective shell. The insulating protective shell is an integrated shell structure with a first opening at one end and an accommodating cavity inside. The battery cell can be inserted and fixed in the accommodating cavity through the first opening to form a battery cell assembly. The battery cell assembly can be integrally installed into the outer shell to assemble into a battery. Since the insulating protective shell is an integrated shell structure, compared with wrapping the mylar film on the battery cell in the related art, the integrated shell structure of the insulating protective shell has no gaps such as splicing, assembly, and bonding, and can effectively play an insulating and protective role for the battery cell, preventing the contact between the free electrolyte and the outer shell, thereby isolating the ion channel and effectively avoiding the problem of electrochemical corrosion of the outer shell, significantly improving the safety and reliability of the battery.

[0095] In addition, inserting the battery cell into the integrated insulating protective shell through the first opening to assemble the battery cell assembly is simpler and has a lower operation difficulty compared with correspondingly wrapping the mylar film on the battery cell and splicing and bonding the mylar film, which is beneficial to improving the assembly efficiency.

[0096] Figure 2 This is a schematic structural diagram of a battery cell assembly provided by an embodiment of the present application.

[0097] See Figure 2 As shown, the battery cell assembly 20 includes a battery cell 21 and an insulating protective case 22. The battery cell 21 is placed inside the insulating protective case 22. The insulating protective case 22 plays an insulating and protective role for the battery cell 21. On the one hand, the insulating protective case 22 can reduce the damage caused to the battery cell 21 by the outer shell during battery assembly. On the other hand, the insulating protective case 22 can play an insulating isolation role between the battery cell 21 and the outer shell, avoiding chemical corrosion of the outer shell caused by the free electrolyte leaking from the battery cell 21.

[0098] In the embodiment of the present application, taking the battery as a square lithium-ion battery as an example, the shapes of the battery cell 21 and the insulating protective case 22 can also be square body structures respectively, such as Figure 2 As shown, taking the width direction of the insulating protective case 22 as the x direction, the length direction of the insulating protective case 22 as the y direction, and the height direction of the insulating protective case 22 as the z direction. In the embodiment of the present application, the width refers to the dimension along the width direction, and the length refers to the dimension along the length direction. It can be understood that the length, width, and thickness in the embodiment of the present application are only for convenience of description and do not mean any limitation on the dimensions. For example, the length can be greater than, equal to, or less than the width.

[0099] Among them, the battery cell 21 can be a bare battery cell. For example, the battery cell 21 can include a positive electrode tab, a negative electrode tab, and a separator (not shown in the figure). The positive electrode tab can have a positive electrode ear, the negative electrode tab can have a negative electrode ear, and the electrolyte may not be injected into the battery cell 21. When forming the battery cell assembly 20 or when the battery cell assembly 20 and the outer shell are assembled into a battery, the electrolyte can be injected into the battery cell 21.

[0100] Alternatively, the battery cell 21 can also be a battery cell structure with electrolyte injected inside.

[0101] Among them, the positive electrode ear and the negative electrode ear can be exposed at one end of the battery cell 21. Exemplarily, for example, the positive electrode ear and the negative electrode ear are exposed on the top end of the battery cell 21. Along the height direction (z direction), the end of the battery cell 21 opposite to the top end is the bottom end of the battery cell 21. Correspondingly, the end of the battery cell assembly 20 on the same side as the top end of the battery cell 21 is the top end of the battery cell assembly 20, and the end of the battery cell assembly 20 on the same side as the bottom end of the battery cell 21 is the bottom end of the battery cell assembly 20.

[0102] The battery cell assembly 20 can further include a top cover 23. The top cover 23 can be fixed on the top end face of the battery cell 21. The top cover 23 can have a positive electrode structure 231 and a negative electrode structure 232 (refer to Figure 7As shown, the positive electrode structure is electrically connected to the positive electrode tab of the battery cell 21, and the negative electrode structure 232 is electrically connected to the negative electrode tab of the battery cell 21.

[0103] The battery cell 21 can be a wound battery cell, that is, the battery cell 21 has a wound structure. For example, after laminating the positive electrode sheet, the separator, and the negative electrode sheet, starting from one end, the positive electrode sheet, the separator, and the negative electrode sheet are wound together in one direction to form a helically wound battery cell 21.

[0104] Alternatively, in some other examples, the battery cell 21 can also be a battery cell of other structural types. For example, the battery cell 21 can also be a stacked battery cell, that is, the positive electrode sheet, the separator, and the negative electrode sheet are stacked.

[0105] Figure 3 is Figure 2 a schematic structural diagram of the insulating protective shell in the battery cell assembly.

[0106] Refer to Figure 3 As shown, the insulating protective shell 22 is an integral shell structure with a first opening 22a at one end and an accommodation cavity 22b inside. That is to say, the insulating protective shell 22 is a shell structure formed by an integral molding method. For example, it can be formed into an integral shell structure through molding methods such as injection molding and blow molding. The formed integral shell structure has a first opening 22a at one end and an accommodation cavity 22b inside.

[0107] The molding material of the insulating protective shell 22 can be a material with corrosion resistance to electrolyte. For example, the molding material of the insulating protective shell 22 can include but is not limited to one or a combination of polyethyleneterephthalate (PET for short), polypropylene (PP for short), polyethylene (PE for short), polytetrafluoroethylene (PTFE for short), etc., which has good corrosion resistance to electrolyte and is beneficial to further improving the safety and stability of the battery.

[0108] Of course, in some other examples, the molding material of the insulating protective shell 22 can also include other organic materials or inorganic materials resistant to electrolyte such as rubber.

[0109] Figure 4 is Figure 3 a schematic diagram of the molding process of the insulating protective shell in.

[0110] Exemplarily, taking the formation of the integral insulating protective shell 22 by blow molding as an example, refer to Figure 4As shown, during actual molding, an integral housing structure 223 can first be formed using a blow molding device 200. The integral housing structure 223 has an accommodation cavity (not shown in the figure) inside. Then, through processes such as cutting and trimming, a first opening 22a is formed at one end of the integral housing structure, thus forming an insulating protective shell 22 with a first opening 22a at one end and an accommodation cavity 22b inside.

[0111] Figure 5 It is Figure 2 a schematic structural diagram of the cell and the insulating protective shell during the assembly process in the cell assembly. Figure 5 The direction indicated by the arrow in the figure is the direction in which the cell 21 is inserted into the insulating protective shell 22.

[0112] Combined with Figure 5 as shown, the cell 21 can pass through the first opening 22a and be accommodated and fixed inside the accommodation cavity 22b of the insulating protective shell 22 to form a cell assembly. It can be understood that when the cell 21 is inserted into the accommodation cavity 22b of the insulating protective shell 22 through the first opening 22a, the bottom end of the cell 21 first enters the accommodation cavity 22b through the first opening 22a. As the cell 21 is inserted, the top end of the cell 21 also passes through the first opening 22a and is accommodated in the accommodation cavity 22b.

[0113] After the cell 21 is placed inside the accommodation cavity 22b of the insulating protective shell 22, the top end of the cell 21 is adjacent to the first opening 22a of the insulating protective shell 22, and the bottom end of the cell 21 is farther away from the first opening 22a of the insulating protective shell 22.

[0114] The top cover 23 on the top end of the cell 21 can be fixed to the end of the insulating protective shell 22 with the first opening 22a (refer to Figure 2 as shown). The top cover 23 can completely cover the first opening 22a. Through the top cover 23, the accommodation cavity 22b of the insulating protective shell 22 can be closed, so that the cell 21 is located inside the closed accommodation cavity 22b, further enhancing the insulation and protection of the cell 21. Moreover, the cell 21 can be fixed through the top cover 23 to prevent the cell 21 from falling during transportation or use.

[0115] Exemplarily, continue to refer to Figure 5 as shown. A plastic layer 24 can be provided on the surface of the top cover 23 facing the insulating protective shell 22. The top cover 23 can be fixed to the insulating protective shell 22 through the plastic layer 24. For example, the plastic layer 24 on the top cover 23 can be fixed to the insulating protective shell 22 by heat sealing. The assembly design is simple and has a very high bonding strength.

[0116] Of course, in some other examples, the top cover 23 or the plastic layer 24 on the top cover 23 can also be fixed to the insulating protective shell 22 by bonding, screw fastening, snap connection, etc.

[0117] Figure 6 For Figure 2 a structural schematic diagram of a battery cell assembly and a housing during the assembly process. Figure 6 The direction in which the battery cell assembly 20 is inserted into the housing 10 is indicated by the arrow in the figure.

[0118] When assembling the battery cell assembly 20 and the housing 10 into the battery 102, as shown in Figure 6 the figure, the insulating protective case 22 containing the battery cells can be inserted into the housing 10 together.

[0119] The insulating protective case 22 is an integral shell structure, and the battery cell 21 is placed inside the insulating protective case 22. Compared with wrapping a mylar film around the battery cell 21 in the related art, the integrated insulating protective case 22 has no gaps such as splicing, assembly, and bonding, and can effectively provide insulation protection for the battery cell 21, effectively isolating the contact between the free electrolyte and the housing 10, thereby isolating the ion channel and avoiding the problem of electrochemical corrosion of the housing 10. Even in the scenario where the negative electrode structure contacts the housing 10 to form an electronic channel, it will not cause electrochemical corrosion to the housing 10, significantly improving the safety and reliability of the battery.

[0120] In addition, the battery cell 21 is inserted into the insulating protective case 22 through the first opening 22a, and the top cover 23 on the battery cell 21 is fixed to the insulating protective case 22 to form the battery cell assembly 20. Compared with wrapping a corresponding mylar film around the battery cell 21 and splicing and bonding the mylar film, the assembly operation is simpler, the operation difficulty is lower, and it is beneficial to improve the assembly efficiency.

[0121] Continuing to refer to Figure 6 the figure, exemplarily, one end of the housing 10 may have a second opening 11, and the housing 10 has a cavity 12 inside. The battery cell assembly 20 composed of the battery cells and the insulating protective case 22 can be inserted through the second opening 11 and placed and fixed in the cavity 12 inside the housing 10, and the housing 10 plays a role of isolating and protecting the battery cell assembly 20.

[0122] It can be understood that when the battery cell assembly 20 is inserted into the cavity 12 inside the housing 10 through the second opening 11, the bottom end of the battery cell assembly 20 first enters the cavity 12 through the second opening 11. As the battery cell assembly 20 is inserted, the top end of the battery cell assembly 20 also enters the cavity 12 through the second opening 11. After the battery cell assembly 20 is placed inside the housing 10, the top end of the battery cell assembly 20 is adjacent to the second opening 11 of the housing 10, and the bottom end of the battery cell assembly 20 is farther away from the second opening 11 of the housing 10.

[0123] Figure 7 For Figure 2 a structural schematic diagram of a battery formed by assembling a battery cell assembly and a housing.

[0124] Combined Figure 7 As shown, the top cover 23 on the top of the battery cell 21 of the battery cell assembly 20 can be fixed to one end of the outer shell 10 with a second opening. The top cover 23 can completely cover the second opening, and the cavity inside the outer shell 10 can also be sealed through the top cover 23, further ensuring that the battery cell is located in a closed space, playing a better role in insulating and protecting the battery cell.

[0125] Exemplarily, the top cover 23 and the outer shell 10 can be fixed together by welding. Of course, in some other examples, the top cover 23 and the outer shell 10 can also be assembled and fixed together by bonding, screw fastening, snap connection and other methods.

[0126] Continue to refer to Figure 7 As shown, a liquid injection hole 233 can also be provided on the top cover 23. The liquid injection hole 233 can be communicated with the inside of the battery cell (not shown in the figure), and the electrolyte can be injected into the battery cell through the liquid injection hole 233.

[0127] An explosion-proof structure 234 can also be provided on the top cover 23. For example, it can be an explosion-proof valve, which plays a role in pressure relief and explosion prevention, improving the safety of the entire battery 102 during operation.

[0128] In the embodiment of the present application, in the above related technology, the battery formed by wrapping the battery cell with spliced mylar film is used as the control group, and the insulation and voltage withstand performance of the battery 102 formed by accommodating the battery cell with the integrated insulation protection case provided in the embodiment of the present application and the battery of the control group are simulated and tested.

[0129] Figure 8 For Figure 7 the schematic diagram of the insulation and voltage withstand test of the battery in Figure 9 is the schematic diagram of the insulation and voltage withstand test of the battery with the battery cell wrapped by mylar film in the related technology.

[0130] Among them, combined Figure 8 and Figure 9 As shown, for the battery 300 of the control group and the battery 102 composed of the integrated insulation protection case of the present application, the structures and assembly relationships of the outer shell (not shown in the figure), the top cover 301, etc. of the battery 300 can be the same as those of the outer shell 10, the top cover 23, etc. of the battery 102 in the embodiment of the present application. The insulation and voltage withstand tests can be performed on the battery 102 provided in the embodiment of the present application and the control group battery 300 in the scenario without injecting electrolyte.

[0131] Table 1 summarizes the insulation and voltage withstand test results of the battery provided in the embodiment of the present application and the control group battery.

[0132]

[0133] As shown in Table 1, for the battery 102 provided in the embodiment of the present application, the insulation withstand voltage can be increased to 3000V in the scenario without injecting electrolyte, and it has good insulation withstand voltage performance, thus significantly improving the safety and reliability of the battery 102.

[0134] In addition, after injecting electrolyte into the battery cell, for the battery 102 provided in the embodiment of the present application, its insulation withstand voltage can be increased to 300V, which also significantly improves the insulation withstand voltage performance of the battery 102 and enhances safety and reliability.

[0135] Figure 10 For Figure 2 Another structural schematic diagram of the insulation protection shell in the battery cell assembly.

[0136] Refer to Figure 10 As shown, the insulation protection shell 22 includes a bottom shell 221 and a side shell 222. The bottom shell 221 and the side shell 222 are of an integral structure, that is, the bottom shell 221 and the side shell 222 form the above-mentioned integral shell structure by an integral molding method. The side shell 222 surrounds the bottom shell 221, and the side shell 222 and the bottom shell 221 enclose a receiving cavity 22b with a first opening 22a at one end. The top cover can be fixed to the end of the side shell 222 facing away from the bottom shell 221.

[0137] Among them, the thicknesses of the bottom shell 221 and the side shell 222 can be 0.02mm - 0.5mm respectively. If the thicknesses of the bottom shell 221 and the side shell 222 are too thin, the integral insulation protection shell 22 is not easy to be integrally formed and the processing difficulty is large. While if the thicknesses of the bottom shell 221 and the side shell 222 are too thick, it will affect the energy density and is not conducive to the electrical performance of the battery cell assembly. Therefore, making the thicknesses of the bottom shell 221 and the side shell 222 be 0.02mm - 0.5mm respectively can reduce or avoid the influence on the energy density, ensure the electrical performance, and can also facilitate the forming of the integral insulation protection shell 22 and is conducive to reducing the forming processing difficulty.

[0138] Exemplarily, the thicknesses of the bottom shell 221 and the side shell 222 can be 0.05mm - 0.2mm respectively, which has less influence on the energy density and better processability.

[0139] It should be noted that the thickness of the bottom shell 221 can be the same as that of the side shell 222. Or, in some examples, the thickness of the bottom shell 221 can also be different from that of the side shell 222, which is conducive to further reducing the forming design and processing difficulty and facilitating the processing and production.

[0140] Continue to refer to Figure 10As shown, the side housing 222 may include a first housing 2221, a second housing 2222, a third housing 2223, and a fourth housing 2224. The first housing 2221 and the second housing 2222 may be opposite to each other in the width direction (x direction), and the third housing 2223 and the fourth housing 2224 may be opposite to each other in the length direction (y direction).

[0141] Among them, that is, the first housing 2221 and the second housing 2222 may be two surfaces with the same structure. The length, height, and thickness of the first housing 2221 may be the same as the length, height, and thickness of the second housing 2222 respectively. The width, height, and thickness of the third housing 2223 may be the same as the width, height, and thickness of the fourth housing 2224 respectively.

[0142] Of course, in some examples, the length, height, and thickness of the first housing 2221 and the second housing 2222 may also be different respectively, and the width, height, and thickness of the third housing 2223 and the fourth housing 2224 may also be different respectively. In the embodiments of the present application, the case where the length, height, and thickness of the first housing 2221, the second housing 2222 are the same respectively, and the width, height, and thickness of the third housing 2223, the fourth housing 2224 are the same respectively is taken as an example for illustration.

[0143] Exemplarily, the lengths of the first housing 2221 and the second housing 2222 may be greater than the widths of the third housing 2223 and the fourth housing 2224 respectively, so that the side housing 222 may be a rectangular ring structure, and the formed insulation protection shell 22 may be a cuboid structure with one end open, which can be used to accommodate a square battery cell and has wide applicability.

[0144] The first housing 2221, the second housing 2222, the third housing 2223, and the fourth housing 2224 may be connected end to end in sequence to enclose a square-ring-shaped side housing 222. Exemplarily, the third housing 2223 and the fourth housing 2224 may be respectively located on both sides of the first housing 2221 and the second housing 2222 in the length direction. The two end faces of the first housing 2221 opposite to each other in the length direction may be respectively attached and connected to one of the two end faces of the third housing 2223 opposite to each other in the width direction and one of the two end faces of the fourth housing 2224 opposite to each other in the width direction. That is, the first housing 2221 is attached and connected to the third housing 2223 and the fourth housing 2224 in sequence at the end faces, and there is no overlapping area in the width direction or the length direction.

[0145] The two end faces of the second housing 2222 opposite to each other in the length direction can be respectively attached to the other end face of the two end faces of the third housing 2223 opposite to each other in the width direction and the other end face of the two end faces of the fourth housing 2224 opposite to each other in the width direction. That is, the second housing 2222 is sequentially attached to the third housing 2223 and the fourth housing 2224, and there is no overlapping area in the width direction or the length direction. The thickness consistency of each surface of the lifting side housing 222 is improved, thereby reducing or avoiding the influence on the energy density distribution due to excessive thickness difference.

[0146] It should be noted that the thicknesses of the first housing 2221, the second housing 2222, the third housing 2223, and the fourth housing 2224 can be the same. Or, in some examples, the thickness of at least one of the first housing 2221, the second housing 2222, the third housing 2223, and the fourth housing 2224 can be different from the thicknesses of the others, further reducing the forming and processing difficulty.

[0147] Exemplarily, taking the thicknesses of the first housing 2221 and the second housing 2222, and the third housing 2223 and the fourth housing 2224 being the same respectively as an example, the thickness of the bottom housing 221 can be 50% - 200% of the thickness of the first housing 2221, and the thickness of the bottom housing 221 can be 50% - 200% of the thickness of the second housing 2222, which not only reduces the influence on the energy density, ensures the electrical performance, but also has good processability.

[0148] The thickness of the third housing 2223 can be 50% - 200% of the thickness of the first housing 2221, and the thickness of the third housing 2223 can be 50% - 200% of the thickness of the second housing 2222. The thickness of the fourth housing 2224 can also be 50% - 200% of the thickness of the first housing 2221, and the thickness of the fourth housing 2224 can also be 50% - 200% of the thickness of the second housing 2222, which can also achieve the effect of reducing the influence on the energy density and having good processability.

[0149] It can be understood that the insulating protective shell 22 is an integral shell structure with an accommodation cavity 22b inside. The inner surface of the insulating protective shell 22 is the surface of the insulating protective shell 22 facing the accommodation cavity 22b, and the outer surface of the insulating protective shell 22 is the surface of the insulating protective shell 22 facing away from the accommodation cavity 22b.

[0150] Figure 11 is Figure 7 a schematic diagram of the length dimension of the battery.

[0151] The length of the inner surface of the insulating protective case 22 is the dimension of the inner surface of the insulating protective case 22 in the length direction, and can also be the inner diameter length of the insulating protective case 22. The length of the inner surface of the insulating protective case 22 can be the distance in the length direction (y direction) between the side of the third housing 2223 facing the accommodation cavity 22b and the side of the fourth housing 2224 facing the accommodation cavity 22b, as Figure 11 shown as L1 in

[0152] The length of the outer surface of the battery cell 21 is the dimension of the outer contour of the battery cell 21 in the length direction, and can also be the outer diameter length of the battery cell 21, as Figure 11 shown as L2 in

[0153] Exemplarily, the ratio L1 / L2 of the length of the inner surface of the insulating protective case 22 to the length of the outer surface of the battery cell 21 can be 1.0 to 1.15, which is convenient for the battery cell 21 to enter the accommodation cavity 22b of the insulating protective case 22 and facilitates assembly.

[0154] For example, the ratio L1 / L2 of the length of the inner surface of the insulating protective case 22 to the length of the outer surface of the battery cell 21 can be 1.0 to 1.1, which enables the battery cell 21 to enter the insulating protective case 22 more conveniently and has high assembly feasibility.

[0154] The length of the outer surface of the insulating protective case 22 is the dimension of the outer surface of the insulating protective case 22 in the length direction, and can also be the outer diameter length of the insulating protective case 22. The length of the outer surface of the insulating protective case 22 can be the distance in the length direction (y direction) between the side of the third housing 2223 facing away from the accommodation cavity 22b and the side of the fourth housing 2224 facing away from the accommodation cavity 22b, as Figure 11 shown as L3 in

[0155] Correspondingly, the inner surface of the outer shell 10 is the side of the outer shell 10 facing the internal cavity 12. The length of the inner surface of the outer shell 10 is the dimension of the inner surface of the outer shell 10 in the length direction, and can also be the inner diameter length of the outer shell 10, as Figure 11 shown as L4 in

[0156] Exemplarily, the ratio L3 / L4 of the length of the outer surface of the insulating protective case 22 to the length of the inner surface of the outer shell 10 can be 0.9 to 1.0, which is convenient for the insulating protective case 22 accommodating the battery cell 21 to enter the cavity 12 of the outer shell 10 and facilitates assembly.

[0157] For example, the ratio of the length of the outer surface of the insulating protective case 22 to the length of the inner surface of the outer shell 10 can be 0.95 to 0.99, which enables the battery cell 21 to enter the insulating protective case 22 more conveniently and has high assembly feasibility.

[0158] Figure 12 It is Figure 7 a schematic diagram of the width dimension of the battery.

[0159] The width of the inner surface of the insulation protective shell 22 is the dimension of the inner surface of the insulation protective shell 22 in the width direction, and can also be the inner diameter width of the insulation protective shell 22. The width of the inner surface of the insulation protective shell 22 can be the spacing in the width direction (x direction) between the side of the first housing 2221 facing the accommodation cavity 22b and the side of the second housing 2222 facing the accommodation cavity 22b, as shown by W1 in Figure 12 Figure

[0160] The width of the outer surface of the battery cell 21 is the dimension of the outer contour of the battery cell 21 in the width direction, and can also be the outer diameter width of the battery cell 21, as shown by W2 in Figure 12 Figure. Exemplarily, the ratio W1 / W2 of the width of the inner surface of the insulation protective shell 22 to the width of the outer surface of the battery cell 21 can be 1.0 to 1.15, which can also facilitate the battery cell 21 to enter the accommodation cavity 22b of the insulation protective shell 22 and is convenient for assembly.

[0161] For example, the ratio of the width of the inner surface of the insulation protective shell 22 to the width of the outer surface of the battery cell 21 can be 1.0 to 1.1, so that the battery cell 21 can enter the insulation protective shell 22 more conveniently and the assembly feasibility is high.

[0162] The width of the outer surface of the insulation protective shell 22 is the dimension of the outer surface of the insulation protective shell 22 in the width direction, and can also be the outer diameter width of the insulation protective shell 22. The width of the outer surface of the insulation protective shell 22 can be the spacing in the width direction (x direction) between the side of the first housing 2221 facing away from the accommodation cavity 22b and the side of the second housing 2222 facing away from the accommodation cavity 22b, as shown by W3 in Figure 12 Figure.

[0163] Correspondingly, the inner surface of the outer shell 10 is the side of the outer shell 10 facing the internal cavity 12. The width of the inner surface of the outer shell 10 is the dimension of the inner surface of the outer shell 10 in the width direction, and can also be the inner diameter width of the outer shell 10, as shown by W4 in Figure 12 Figure.

[0164] Exemplarily, the ratio W3 / W4 of the width of the outer surface of the insulation protective shell 22 to the width of the inner surface of the outer shell 10 can be 0.9 to 1.0, which can also facilitate the insulation protective shell 22 accommodating the battery cell 21 to enter the cavity 12 of the outer shell 10 and is convenient for assembly.

[0165] For example, the ratio of the width of the outer surface of the insulation protective shell 22 to the width of the inner surface of the outer shell 10 can be 0.95 to 0.99, so that the battery cell 21 can enter the insulation protective shell 22 more conveniently and the assembly feasibility is high.

[0166] Figure 13 This is a schematic structural diagram of another battery cell assembly provided by an embodiment of the present application.

[0167] To further improve the convenience of assembling the battery cell component 20 with the outer shell, refer to Figure 13 As shown, a groove 2225 may also be provided on the side shell 222 of the insulating protective shell 22. The groove 2225 is formed on the side of the side shell 222 facing away from the accommodation cavity, and the groove 2225 may be formed by the side shell 222 being recessed toward the accommodation cavity.

[0168] When the insulating protective shell 22 containing the battery cell 21 is inserted into the inner cavity of the outer shell, the groove 2225 on the side shell 222 may form an exhaust passage, allowing the air in the outer shell cavity to be discharged through the groove 2225, reducing or avoiding the air pressure resistance during the insertion process, making it more convenient to insert the battery cell component 20 into the outer shell and improving the assembly convenience.

[0169] Exemplarily, the recessed depth of the groove 2225 may be 0.01 mm to 5 mm. Under the condition that the setting of the groove 2225 has little influence on the accommodation capacity of the accommodation cavity inside the insulating protective shell 22, the exhaust effect of the groove 2225 is ensured, and the assembly convenience is ensured.

[0170] For example, the recessed depth of the groove 2225 may be 0.01 mm to 2 mm, which has little influence on the capacity of the accommodation cavity and has a good exhaust effect, and the assembly convenience is higher.

[0171] Among them, the number of the grooves 2225 may be one, or the number of the grooves 2225 may also be multiple, which is not limited in the embodiments of the present application.

[0172] In the embodiments of the present application, the position of the groove 2225 on the side shell 222 is not limited either. The extending direction of the groove 2225 may be consistent with the height direction of the insulating protective shell 22. Of course, in some examples, the extending direction of the groove 2225 may also be inclined to the height direction.

[0173] For example, the groove 2225 may be formed on at least one of the first shell, the second shell, the third shell, and the fourth shell of the side shell 222. For example, the first shell, the second shell, the third shell, and the fourth shell may all have the groove 2225, or one or several of the first shell, the second shell, the third shell, and the fourth shell may have the groove 2225.

[0174] In one example, the material of the insulation protective shell 22 can be polyethylene, and the integral insulation protective shell 22 can be formed by blow molding. The thicknesses of the first shell and the second shell of the insulation protective shell 22 can be 0.1 mm respectively, and the thicknesses of the third shell and the fourth shell can be 0.15 mm respectively. The ratio of the length of the inner surface of the insulation protective shell 22 to the length of the outer surface of the battery cell 21 can be 1.05, and the ratio of the width of the inner surface of the insulation protective shell 22 to the width of the outer surface of the battery cell 21 can be 1.05. The ratio of the length of the outer surface of the insulation protective shell 22 to the length of the inner surface of the outer shell can be 0.98, and the ratio of the width of the outer surface of the insulation protective shell 22 to the width of the inner surface of the outer shell can be 0.98. Grooves 2225 can be respectively arranged on the third shell and the fourth shell of the insulation protective shell 22, and the depth of the grooves 2225 can be 0.05 mm. The battery cell 21 is placed into the insulation protective shell 22, and the plastic layer of the top cover is bonded to the insulation protective shell 22 by heat sealing. The formed battery cell assembly 20 has high safety and stability.

[0175] It can be understood that one insulation protective shell 22 can fixedly accommodate one battery cell 21, or one insulation protective shell 22 can also fixedly accommodate multiple battery cells 21.

[0176] When there are multiple battery cells 21 in one insulation protective shell 22, the multiple battery cells 21 can be arranged side by side in sequence along the width direction or the length direction, and the positions of the grooves 2225 on the side shell 222 can correspond to the positions where two adjacent battery cells 21 are in contact with each other.

[0177] Exemplarily, as Figure 13 shown in, taking the example that there are four battery cells 21 in one insulation protective shell 22, the four battery cells 21 can be arranged side by side in sequence along the width direction, and there will be a gap between the edge parts of two adjacent battery cells 21 and they will not be completely in contact. The positions of the grooves 2225 on the side shell 222 can be made to correspond to the positions where two adjacent battery cells 21 are in contact (such as at least partially overlapping in the projection in the length direction), that is, the inwardly concave grooves 2225 on the side shell 222 can be recessed and extended into the gap between the contact parts of two adjacent battery cells 21. The design is compact to improve the integration degree, and it is more beneficial to reduce the influence of the recessed grooves 2225 on the capacity of the accommodation cavity in the insulation protective shell 22.

[0178] It should be noted that the numerical values and numerical ranges involved in the embodiments of the present application are approximate values, and there may be a certain range of errors, which can be considered negligible by those skilled in the art.

[0179] In the description of the embodiments of the present application, it should be noted that unless otherwise clearly defined and limited, the terms "installed", "connected", and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, or an indirect connection through an intermediate medium, and can be the connection inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances. The terms "first", "second", "third", "fourth", etc. (if any) are used to distinguish similar objects and do not necessarily need to describe a specific order or sequence.

[0180] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of the present application, and not to limit them; although the embodiments of the present application have been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or equivalently replace some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery cell assembly, characterized in that, Comprising: An electric core; An insulating protective case, which is an integrally formed case structure with a first opening at one end and an accommodation cavity inside. The first opening is used for the electric core to pass through and be fixed inside the accommodation cavity; The insulating protective case includes a bottom case and a side case surrounding the bottom case. A groove is provided on a surface of the side case facing away from the accommodation cavity.

2. The cell assembly according to claim 1, wherein, It further includes a top cover, which is fixed on the top end face of the electric core. The top cover is fixed to the end of the insulating protective case with the first opening, and the top cover covers the first opening.

3. The battery cell assembly according to claim 2, characterized in that, The bottom case and the side case enclose the accommodation cavity with the first opening at one end. The bottom case and the side case are of an integrally formed structure; The top cover is fixed to the end of the side case facing away from the bottom case.

4. The cell assembly according to claim 3, wherein, The thicknesses of the bottom case and the side case are respectively 0.02 mm to 0.5 mm.

5. The cell assembly according to claim 3, wherein, The side case includes a first case, a second case, a third case, and a fourth case. The first case and the second case are opposite in the width direction, and the third case and the fourth case are opposite in the length direction; Two end faces of the first case opposite in the length direction are respectively in fit connection with one end face of the third case in the width direction and one end face of the fourth case in the width direction; Two end faces of the second case opposite in the length direction are respectively in fit connection with the other end face of the third case in the width direction and the other end face of the fourth case in the width direction. The first case, the second case, the third case, and the fourth case enclose the square-ring-shaped side case.

6. The cell assembly according to claim 5, wherein, The length of the first case is respectively greater than the widths of the third case and the fourth case; The length of the second case is respectively greater than the widths of the third case and the fourth case.

7. The cell assembly according to claim 6, wherein The thickness of the bottom case is respectively 50% to 200% of the thicknesses of the first case and the second case.

8. The cell assembly according to claim 6, wherein The thickness of the third case is respectively 50% to 200% of the thicknesses of the first case and the second case; The thickness of the fourth case is respectively 50% to 200% of the thicknesses of the first case and the second case.

9. The cell assembly according to any one of claims 1-8, characterized in that, The ratio of the inner surface length of the insulating protective case to the outer surface length of the electric core is 1.0 to 1.

15.

10. The cell assembly according to any one of claims 1-8, characterized in that, The ratio of the inner surface width of the insulating protective case to the outer surface width of the electric core is 1.0 to 1.

15.

11. The cell assembly according to any one of claims 1-8, characterized in that, The depth of the groove is 0.01 mm to 5 mm.

12. The cell assembly according to any one of claims 2-6, characterized in that, A plastic layer is provided on a surface of the top cover facing the insulating protective case. The top cover is fixed to the insulating protective case through the plastic layer.

13. The battery cell assembly according to any one of claims 1-8, characterized in that, The material of the insulating protective case includes one of polyethylene terephthalate, polypropylene, polyethylene, and polytetrafluoroethylene.

14. A battery, characterized in that, Comprising a housing and the electric core assembly according to any one of claims 1-13 above, and the electric core assembly is accommodated inside the housing.

15. The battery according to claim 14, characterized in that, One end of the housing has a second opening, and the second opening is used for the electric core assembly to pass through and be fixed inside the housing; The top cover of the electric core assembly is fixed to the end of the housing with the second opening, and the top cover covers the second opening.

16. The battery according to claim 14, characterized in that, The ratio of the outer surface length of the insulating protective case of the battery cell assembly to the inner surface length of the outer case is 0.9 to 1.

0.

17. The battery according to claim 14, characterized in that, The ratio of the outer surface width of the insulating protective case of the battery cell assembly to the inner surface width of the outer case is 0.9 to 1.

0.

18. An energy storage system, characterized in that, Comprising a control unit and the battery according to any one of claims 14-17 above, the control unit being adapted to be connected to the battery.

19. A device, characterized in that, Comprising a housing and the energy storage system according to claim 18 above, the energy storage system being assembled on the housing.

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