Battery cells and battery pack

Abstract

The present utility model provides a battery cell and a battery pack. The battery cell includes: a casing and a cell core, the cell core being positioned inside the casing; the battery cell also includes an additional layer formed by coating, the additional layer being positioned between the cell core and the casing, and the additional layer being an insulating material layer. The present utility model can achieve electrical insulation in the battery cell between the cell core and the casing.

Description

[0001] FIELD OF THE INVENTION The present invention relates to the field of battery technology, specifically to a battery cell and battery pack. BACKGROUND In the prior art, before inserting a battery cell stack or jelly roll into a battery casing, the stack or roll is typically wrapped with an insulating film (e.g., polyester film). The insulating film stabilizes the stack or roll during insertion and electrically insulates it from the metal casing. However, the wrapping method of the insulating film and the use of adhesive tape to secure the stack or roll result in irregular structures (e.g., irregular edges, notches, and protrusions) on the surface of the cell stack or roll. During operation of the battery cell, it has been observed that the breathing and expansion of the cell stack or roll lead to an increase in internal pressure. Irregular structures on the surface of the battery cell can reduce the battery's rapid charging capability and service life. During rapid charging of the battery cell, heat is generated. Because this heat is generated at certain points within the battery cell, it results in uneven temperature distribution within the cell. If local temperatures are too high, they may damage battery cell components, posing safety risks and reducing battery life. Existing solutions typically use external cooling, which fails to ensure uniform temperature distribution within individual battery cells. Therefore, there is a need for an improved battery cell that overcomes or mitigates at least some of the shortcomings of the prior art. SUMMARY OF THE INVENTION In a first aspect, the present invention provides a battery cell comprising: a housing and a cell core disposed within the housing; the cell core further comprising an additional layer formed by coating, disposed between the cell core and the housing, and comprising an insulating material layer. Optionally, the additional layer is a first additional layer, coated on the outer surface of the cell core, and the second additional layer is a layer of insulating and thermally conductive material, or a layer of insulating but non-thermally conductive material.Optionally, the first additional layer covers 1%-99% of the outer surface of the cell core; the thickness of the first additional layer is 0.1 [im-100[im]. Optionally, the first additional layer covers 80%-99% of the outer surface of the cell core; the thickness of the first additional layer is 3 [im-20[im]. Optionally, the first additional layer is applied to the cell core by spraying, dripping, dipping, coating, or vapor deposition. Optionally, the battery cell further includes an insulating film, the additional layer is a second additional layer, the insulating film wraps the cell core, the second additional layer is applied to the inner surface of the insulating film near the cell core, and the second additional layer is a layer of insulating and thermally conductive material. Optionally, the second additional layer covers 1%-100% of the inner surface of the insulating film; the thickness of the second additional layer is 0.1 [im-100[imo. Optionally, the second additional layer covers 80%-97% of the inner surface of the insulating film; the thickness of the second additional layer is 3[im-20[imo. Optionally, the second additional layer is applied to the insulating film by spraying, dipping, coating or vapor deposition. In a second aspect of the present invention, a battery pack is provided, which includes a plurality of the aforementioned battery cells. The battery cell of the present invention is configured to include a shell, a cell core and an additional layer formed by coating, and the additional layer is arranged between the cell core and the shell. The additional layer is an insulating material layer, so that electrical insulation between the cell core and the shell can be simply achieved. Furthermore, the battery cell of the present invention directly applies a first additional layer to the outer surface of the cell core. The first additional layer is made of either an insulating and thermally conductive material or an insulating but non-thermally conductive material. This not only achieves electrical insulation between the cell core and the housing, but also, when the first additional layer is made of an insulating and thermally conductive material, it also serves as a temperature conductor. This allows for a more uniform temperature distribution within the battery cell, thereby protecting the battery cell components from damage, ensuring high safety, and extending the battery life.Furthermore, the battery cell of the present invention is configured to further include an insulating film, which wraps the cell core. A second additional layer is applied to the inner surface of the insulating film near the cell core. The second additional layer is a layer of insulating and thermally conductive material, so that the insulating film also performs temperature conduction. This allows the insulating film to perform temperature conduction, thereby achieving a more uniform temperature distribution within the battery cell, thereby ensuring that the battery cell components are protected from damage, providing enhanced safety, and a long service life. The above and other objects, advantages, and features of the present invention will become more apparent to those skilled in the art from the detailed description of specific embodiments of the present invention below, combined with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS The features, advantages, and exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, in which like reference numerals indicate like elements. FIG. 1 is a schematic exploded perspective view of a battery cell according to an embodiment of the present invention. FIG. 2 is a schematic partial cross-sectional view of one embodiment of the battery cell of FIG. FIG. 3 is a schematic partial cross-sectional view of another embodiment of the battery cell of FIG. DETAILED DESCRIPTION Exemplary embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The description of the exemplary embodiments is merely illustrative and in no way limits the present invention, its applications, or uses. Furthermore, the dimensions and proportions of the components in the figures are merely schematic and do not strictly correspond to actual products. The present invention provides a battery cell 100, a battery pack containing multiple battery cells 100, and a device containing one or more battery cells 100. The battery cell 100 in this embodiment comprises a housing 101 and at least one cell core 102 disposed within the housing 101. The battery cell 100 also includes an additional layer formed by coating, disposed between the cell core 102 and the housing 101, and comprising an electrically insulating material.The battery cell 100 of this embodiment of the present invention comprises a housing 101, a cell core 102, and an additional layer formed by coating. The additional layer is disposed between the cell core 102 and the housing 101 and is made of an insulating material, thereby simplifying electrical insulation between the cell core 102 and the housing 101. In this embodiment of the battery cell 100, the additional layer is a first additional layer 103, which is directly coated on the outer surface of the cell core 102 and is made of either an insulating and thermally conductive material or an insulating but non-thermally conductive material. Alternatively, the battery cell 100 further includes an insulating film 104, and the additional layer is a second additional layer 105, which wraps around the cell core 102 and is coated on the inner surface of the insulating film 104 near the cell core 102 and is made of an insulating and thermally conductive material.A battery cell 100 according to one embodiment of the present invention is configured to include a housing 101 and a cell core 102, and further include a first additional layer 103. The first additional layer 103 is directly applied to the outer surface of the cell core 102. The first additional layer 103 is made of either an insulating and thermally conductive material or an insulating but non-thermally conductive material. This provides electrical insulation between the cell core 102 and the housing 101. Furthermore, when the first additional layer 103 is made of an insulating and thermally conductive material, it also provides temperature conduction, thereby achieving a more uniform temperature distribution within the battery cell 100, thereby protecting the components of the battery cell 100 from damage, ensuring high safety, and a long service life. Furthermore, the provision of the first additional layer 103 provides a smooth surface for the cell core 102, allowing the cell core 102 to be easily slid into / inserted into the housing 101 / casing of the battery cell 100, thereby improving battery production efficiency. Furthermore, because the first additional layer 103 is directly applied to the outer surface of the cell core 102, a conventional insulating film is not required. This ensures that the surface of the cell core 102 does not have irregular edges, notches, protrusions, or fixing materials (such as tape), thereby ensuring the battery's fast charging capability and service life. It also reduces the need for wrapping and securing with tape, thereby improving battery production efficiency. Another embodiment of the present invention comprises a battery cell 100 comprising a housing 101 and a cell core 102, as well as an insulating film 104 and a second additional layer 105. The insulating film 104 wraps the cell core 102, and the second additional layer 105 is applied to the inner surface of the insulating film 104 near the cell core 102. The second additional layer 105 is a layer of insulating and thermally conductive material, allowing it to also perform temperature conduction. This achieves a more uniform temperature distribution within the battery cell 100, thereby ensuring that the components of the battery cell 100 are protected from damage, ensuring high safety, and a long service life. The provision of the second additional layer 105 also ensures the stability of the insulating film 104 wrapping.It will be appreciated that when the second additional layer 105 is provided, the thickness of the insulating film 104 itself can be reduced so as not to reduce the energy density of the battery cell 100. In embodiments of the present invention, the battery cell 100 is typically a prismatic battery cell, and the cell core 102 is a cell stack or roll. A cell stack may also be referred to as a laminated cell, a layered cell, or a stacked cell, while a cell roll may also be referred to as a wound cell, a jelly roll cell, or a rolled cell. The housing 101 is typically a metal housing, such as an aluminum housing. The insulating film 104 is typically a polyester film or foil. The battery pack in embodiments of the present invention may include multiple battery cells 100. The number of battery cells 100 in a battery pack can be adjusted according to actual needs. For example, a battery pack may include four, six, or twelve battery cells 100. A device in embodiments of the present invention may include one or more battery cells 100, and the device may be a mobile device or a stationary device. A mobile device may be, for example, an electric vehicle. The following describes in more detail the components of the battery cell 100 according to an embodiment of the present invention, with reference to the accompanying drawings. Referring to Figure 2, which is a partial cross-sectional schematic diagram of an embodiment of the battery cell 100 according to the present invention, the battery cell 100 may include a housing 101, a cell core 102, and a first additional layer 103. The cell core 102 is disposed within the housing 101. The first additional layer 103 is directly applied to the outer surface of the cell core 102. Herein, "directly" means that no other layers or structures exist between the first additional layer 103 and the cell core 102. It is understood that in addition to the housing 101 and cell core 102, the battery cell 100 may also include other conventional battery cell structures, such as a frame and a vent 110 provided on the housing 101, which will not be described in detail here. The first additional layer 103 may be a layer of insulating and thermally conductive material. Alternatively, the first additional layer 103 may be a layer of insulating but non-thermally conductive material. When the first additional layer 103 is an insulating and heat-conducting material layer, the first additional layer 103 plays the role of insulation and heat conduction, and may also provide support.Typically, when the first additional layer 103 is an insulating and thermally conductive material layer, the thermal conductivity can be 4 W / (m K) to 100 W / (m K), for example, 4 W / (m K), 50 W / (m K), or 100 W / (m K); preferably, 6 W / (m K) to 14 W / (m K), for example, 6 W / (m K), 8 W / (m K), or 14 W / (m K). A thermal conductivity of 6 W / (m K) to 14 W / (m K) helps achieve a balance between cost and thermal conductivity. When the first additional layer 103 is an insulating but non-thermally conductive material layer, it serves as an insulator and may also provide support. When the first additional layer is an insulating and thermally conductive material layer, the material used for the first additional layer can be an insulating and thermally conductive material known in the art. When the first additional layer 103 is an insulating but non-thermally conductive material layer, the material used for the first additional layer can be an insulating but non-thermally conductive material known in the art. The material for the first additional layer generally includes a polymer and a filler. The polymer may be selected from the group consisting of polyimide (PI), polyethylene terephthalate (PET), polypropylene (PP), polycarbonate (PC), eritryto 1, chemically compatible adhesives, epoxy resins, and silicone rubber. The filler may be selected from the group consisting of aluminum nitride (AlN), boron nitride (BN), aluminum oxide (Al2O3), silicon carbide (SiC), silicon dioxide (SiCl2), zinc oxide (ZnO), silicon nitride (Si3N4), graphite, graphene, carbon nanotubes (CNT), carbon nanofibers, and diamond. By adjusting the ratio of the polymer to the filler, materials for the first additional layer with varying properties can be obtained. It is understood that the polymer and filler can be mixed using any conventional method for obtaining the material for the first additional layer, and this is not limited herein. The first additional layer 103 can be applied to the monomer core 102 by spraying, dripping, dipping, coating (including dry coating and wet coating), or vapor deposition (including chemical vapor deposition (CVD) and physical vapor deposition (PVD). It is understood that the specific implementation steps of spraying, dripping, dipping, coating, or vapor deposition can be performed using existing technologies and will not be described in detail here.Pores for electrolyte wetting must be retained on the cells, especially at the bottom of the cells. Therefore, the first additional layer 103 can cover 1%-99% of the outer surface of the cell core 102. For example, the first additional layer 103 covers 1%, 50%, 95%, or 99% of the outer surface of the cell core 102. Preferably, the first additional layer 103 covers 50%-95% of the outer surface of the cell core 102. Preferably, the first additional layer 103 covers 80%-99% of the outer surface of the cell core 102. For example, the first additional layer 103 covers 80%, 90%, or 99% of the outer surface of the cell core 102. When the first additional layer 103 covers 80%-99% of the outer surface of the cell core 102, a balance is achieved between electrolyte wetting pores, insulation effect, and energy density. This partial coverage can be achieved, for example, by providing a shield on the battery cell 100 or the spray head during coating. Taking the directions shown in FIG. 1 as an example, the x direction represents the left-right direction, the y direction represents the up-down direction, and the z direction represents the front-back direction. The first additional layer 103 may fully cover the upper, left, right, and front and back surfaces of the monomer core 102, while partially covering the lower surface to preserve electrolyte wetting holes. The first additional layer 103 may also fully cover the left, right, and front and back surfaces of the monomer core 102, but not the upper and lower surfaces. The first additional layer 103 may also partially cover the left, right, and front and back surfaces of the monomer core 102, and partially cover the upper and lower surfaces. The thickness of the first additional layer 103 may be 0.1 ppm to 100 ppm. For example, the thickness of the first additional layer 103 is 0.1 ppm, 50 ppm, or 100 ppm. Preferably, the thickness of the first additional layer 103 may be 3 μm to 20 μm. For example, the thickness of the first additional layer 103 is 3 μm, 10 μm, or 20 μm. When the thickness of the first additional layer 103 is preferably 3 μm to 20 μm, a better balance is achieved between the loss of robustness (i.e., stability) and energy density. By providing this lighter and thinner first additional layer 103 and eliminating the need for a fixing structure such as tape, the weight of the battery cell 100 can be reduced while increasing the energy density. Referring to FIG. 3 , FIG. 3 is a partial cross-sectional schematic diagram of another embodiment of a battery cell 100 of the present invention.The battery cell 100 may include a housing 101, a cell core 102, an insulating film 104, and a second additional layer 105. The cell core 102 is disposed within the housing 101. The insulating film 104 encases the cell core 102, and the second additional layer 105 is applied to the inner surface of the insulating film 104 near the cell core 102. The second additional layer 105 is a layer of insulating and thermally conductive material. Similarly, in addition to the housing 101 and cell core 102, the battery cell 100 may also include other conventional battery cell structures, such as a frame and a vent 110 provided on the housing 101, which will not be described in detail here. The thermal conductivity of the second additional layer 105 can be 4 W / (mK) to 100 W / (mK), for example, 4 W / (mK), 50 W / (mK), or 100 W / (mK); preferably, 6 W / (mK) to 14 W / (mK), for example, 6 W / (mK), 8 W / (mK), or 14 W / (mK). A thermal conductivity of 6 W / (mK) to 14 W / (mK) helps achieve a balance between cost and thermal conductivity. The second additional layer can be made of insulating and thermally conductive materials known in the art. The material for the second additional layer generally includes a polymer and a filler. The polymer can be selected from the group consisting of polyimide (PL), polyethylene terephthalate (PET), polypropylene (PP), polycarbonate (PC), eritryto 1, chemically compatible adhesives, epoxy resins, and silicone rubber. The filler can be selected from the group consisting of aluminum nitride (AlN), boron nitride (BN), aluminum oxide (Al2O3), silicon carbide (SiC), silicon dioxide (SiO2), zinc oxide (ZnO), silicon nitride (Si3N4), graphite, graphene, carbon nanotubes (CNT), carbon nanofibers, and diamond. It is understood that the polymer and filler can be mixed using any conventional method for obtaining the material for the second additional layer, and this is not limited herein. The second additional layer 105 can be applied to the insulating film 104 by spraying, dipping, coating (including dry coating and wet coating), or vapor deposition (including chemical vapor deposition (CVD) and physical vapor deposition (PVD). It is understandable that the specific implementation steps of spraying, dipping, coating or vapor deposition can be performed using existing technologies and will not be described in detail here.The second additional layer 105 may cover 1%-100% of the inner surface of the insulating film 104 . For example, the second additional layer 105 covers 1%, 50%, or 100% of the inner surface of the insulating film 104 . o In a preferred embodiment, the second additional layer 105 covers 1%-99% of the inner surface of the insulating film 104. In a preferred embodiment, the second additional layer 105 covers 3%-97% of the inner surface of the insulating film 104. o In a preferred embodiment, the second additional layer 105 covers 20%-80% of the inner surface of the insulating film 104. In a preferred embodiment, the second additional layer 105 covers 80%-97% of the inner surface of the insulating film 104. For example, the second additional layer 105 covers 80%, 90%, or 97% of the inner surface of the insulating film 104. Such partial coverage can be achieved, for example, by providing a shield on the insulating film 104 or the showerhead during coating. Taking the directions shown in FIG. 1 as an example, the x direction represents the left-right direction, the y direction represents the up-down direction, and the z direction represents the front-back direction. When the insulating film 104 is wrapped around the monomer core 102, the second additional layer 105 can fully cover the upper and lower regions, the left and right regions, and the front-back regions of the inner surface of the insulating film 104. The second additional layer 105 can also fully cover the left and right regions and the front-back regions of the inner surface of the insulating film 104, but not the upper and lower regions. The second additional layer 105 can also partially cover the left and right regions of the inner surface of the insulating film 104, and partially cover the upper and lower regions and the front-back regions. The thickness of the second additional layer 105 can range from 0.1 ppm to 100 ppm. For example, the thickness of the second additional layer 105 is 0.1 ppm, 50 ppm, or 100 ppm. In a preferred embodiment, the thickness of the second additional layer 105 may be 3 μm to 20 μm. For example, the thickness of the second additional layer 105 is 3 μm, 10 μm, or 20 μm. o In the description of this specification, reference is made to the terms "one embodiment", "some embodiments",

[0002] References to "one embodiment," "some embodiments," or "preferred embodiments" mean that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. The above describes the embodiments of the present invention in detail. However, aspects of the present invention are not limited to the above embodiments. Various modifications and substitutions may be applied to the above embodiments without departing from the scope of the present invention.

Claims

Claims 1. A battery cell, characterized in that: The battery cell comprises: a shell and a monomer core, wherein the monomer core is arranged inside the shell; wherein the battery cell further comprises an additional layer formed by coating, wherein the additional layer is arranged between the monomer core and the shell, and the additional layer is an insulating material layer.

2. The battery cell according to claim 1, characterized in that: The additional layer is a first additional layer, which is coated on the outer surface of the monomer core. The first additional layer is an insulating and heat-conductive material layer or an insulating but non-heat-conductive material layer.

3. The battery cell according to claim 2, characterized in that: The first additional layer covers 1%-99% of the outer surface of the monomer core; the thickness of the first additional layer is 0.1 [im-100[imo 4. The battery cell according to claim 2 or 3, characterized in that: The first additional layer covers 80%-99% of the outer surface of the monomer core; the thickness of the first additional layer is 3[im-20[imo 5. The battery cell according to claim 2 or 3, characterized in that the first additional layer is applied to the cell core by spraying, dripping, dipping, coating or vapor deposition.

6. The battery cell according to claim 1, characterized in that: The battery cell further includes an insulating film, the additional layer is a second additional layer, the insulating film wraps the cell core, the second additional layer is coated on the inner surface of the insulating film close to the cell core, and the second additional layer is an insulating and heat-conductive material layer.

7. The battery cell according to claim 6, characterized in that: The second additional layer covers 1%-100% of the inner surface of the insulating film; the thickness of the second additional layer is 0.1 [im-100[imo 9 8. The battery cell according to claim 6 or 7, characterized in that: The second additional layer covers 80%-97% of the inner surface of the insulating film; the thickness of the second additional layer is 3[im-20[imo 9. The battery cell according to claim 6 or 7 is characterized in that the second additional layer is applied to the insulating film by spraying, dipping, coating or vapor deposition.

10. A battery pack, characterized in that: The battery pack comprises a plurality of battery cells according to any one of claims 1-9.

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