Quadrangular prism battery and battery device

Abstract

The utility model relates to the technical field of batteries, and provides a quadrangular prism battery and a battery device, the quadrangular prism battery comprises a battery shell and a roll core, and the battery shell is a steel shell; the roll core is at least partially located in the battery shell, the roll core comprises a positive plate, a negative plate and a diaphragm, the diaphragm is located between the positive plate and the negative plate, and the positive plate comprises a positive current collector layer and a positive active material layer located on at least one side of the positive current collector layer; the negative plate comprises a negative current collector layer and a negative active material layer positioned on at least one side of the negative current collector layer; wherein the negative electrode active material layer is arranged to exceed the positive electrode active material layer, the size of the negative electrode active material layer exceeding the positive electrode active material layer is greater than or equal to 0.8 mm, and the heat conductivity coefficient of the battery shell 1 is 15 w / (m.k)-90 w / (m.k). The quadrangular prism battery has relatively high charging efficiency.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a quadrangular prism battery and a battery device. Background Art

[0002] The battery shell of the battery generally uses an aluminum shell structure. However, the strength of the aluminum shell is relatively low and it is easy to deform, and the cost of the aluminum shell is relatively high. In the related art, a steel shell can be used to replace the aluminum shell. However, the thermal conductivity of the steel shell is low. At the same time, since the negative electrode sheet is an endothermic reaction during the charging process of the battery, the steel shell with low thermal conductivity efficiency will affect the heat absorption of the negative electrode sheet from the outside of the battery shell, thereby affecting the charging efficiency of the battery.

[0003] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Utility Model Content

[0004] The utility model provides a quadrangular prism battery, which can improve the technical problem of slow battery charging efficiency.

[0005] The quadrangular prism battery includes:

[0006] Battery shell, the battery shell is a steel shell;

[0007] A winding core is at least partially located in the battery housing, and the winding core includes:

[0008] A positive electrode sheet, the positive electrode sheet comprising a positive electrode current collector layer and a positive electrode active material layer located on at least one side of the positive electrode current collector layer;

[0009] A negative electrode sheet, the negative electrode sheet comprising a negative electrode current collector layer and a negative electrode active material layer located on at least one side of the negative electrode current collector layer;

[0010] The separator is located between the positive and negative electrodes;

[0011] The negative electrode active material layer is arranged beyond the positive electrode active material layer, the dimension of the negative electrode active material layer beyond the positive electrode active material layer is greater than or equal to 0.8 mm, and the thermal conductivity of the battery shell is 15w / (m·k)-90w / (m·k).

[0012] The thermal conductivity of the steel shell is low, and the negative electrode sheet is an endothermic reaction during the charging process. The utility model sets the negative electrode active material layer beyond the positive electrode active material layer, and the negative electrode active material layer can be closer to the battery housing. This setting can increase the speed at which the negative electrode sheet absorbs heat from the outside of the battery housing, thereby improving the charging efficiency of the battery. At the same time, the size of the negative electrode active material layer exceeding the positive electrode active material layer is too small, and the battery charging efficiency is not significantly improved. The utility model sets the size of the negative electrode active material layer exceeding the positive electrode active material layer to a suitable size, and this setting can improve the charging efficiency of the quadrangular prism battery. In addition, the steel shell is more easily corroded under high potential. The utility model sets the negative electrode active material layer beyond the positive electrode active material layer, thereby reducing the risk of short circuit between the battery housing and the positive electrode sheet, and further reducing the risk of corrosion of the battery housing.

[0013] The utility model also provides a battery device, which includes the above-mentioned quadrangular prism battery and has the technical effect of the above-mentioned quadrangular prism battery.

[0014] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to better understand the present disclosure, reference may be made to the embodiments shown in the following drawings. The components in the drawings are not necessarily to scale, and related elements may be omitted in order to emphasize and clearly illustrate the technical features of the present disclosure. In addition, related elements or components may have different arrangements as known in the art. In addition, in the drawings, the same reference numerals represent the same or similar components in each drawing.

[0016] in:

[0017] Figure 1 This is a schematic structural diagram of an exemplary embodiment of a quadrangular prism battery disclosed herein;

[0018] Figure 2 This is a schematic diagram of the structure of the winding core in an exemplary embodiment of the quadrangular prism battery disclosed in the present invention;

[0019] Figure 3 A cross-sectional view of a winding core in an exemplary embodiment of a quadrangular prism battery disclosed herein;

[0020] Figure 4 A schematic diagram of the stacked structure of positive and negative electrode sheets in an exemplary embodiment of the quadrangular prism battery disclosed herein;

[0021] Figure 5 It is a structural schematic diagram of an exemplary embodiment of the battery device disclosed in the present invention;

[0022] Figure 6FIG. 4 is a schematic structural diagram of another exemplary embodiment of a battery device disclosed herein.

[0023] Description of reference numerals:

[0024] 1. Battery case; 2. Winding core; 21. Positive electrode sheet; 211. Positive current collector layer; 212. Positive active material layer; 22. Negative electrode sheet; 221. Negative current collector layer; 222. Negative active material layer; 23. Diaphragm; 24. Single-piece positive electrode ear; 25. Single-piece negative electrode ear; 3. Heating layer; 4. Battery case; 41. Bottom plate; 5. Quadrangular prism battery; 51. First side; 52. Second side; 53. Third side. DETAILED DESCRIPTION

[0025] The following will be combined with the accompanying drawings in the exemplary embodiments of the present disclosure to clearly and completely describe the technical solutions in the exemplary embodiments of the present disclosure. The exemplary embodiments described herein are only for illustrative purposes and are not intended to limit the scope of protection of the present disclosure. Therefore, it should be understood that various modifications and changes can be made to the exemplary embodiments without departing from the scope of protection of the present disclosure.

[0026] In the description of the present disclosure, unless otherwise clearly specified and limited, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance; the term "plurality" refers to two or more; the term "and / or" includes any and all combinations of one or more associated listed items. In particular, reference to "the / the" object or "an" object is also intended to indicate one of a possible plurality of such objects.

[0027] Unless otherwise specified or explained, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, an integral connection, an electrical connection, or a signal connection; "connection" can be a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meanings of the above terms in this disclosure can be understood according to specific circumstances.

[0028] Further, in the description of the present disclosure, it should be understood that the directional words such as "upper", "lower", "inner", "outer" and the like described in the exemplary embodiments of the present disclosure are described at the angles shown in the accompanying drawings and should not be understood as limitations on the exemplary embodiments of the present disclosure. It should also be understood that, in the context, when it is mentioned that an element or feature is connected to one or more "upper", "lower", or "inner", "outer" of another element, it can not only be directly connected to the "upper", "lower", "inner", "outer" of another element or elements, but can also be indirectly connected to the "upper", "lower", "inner", "outer" of another element or elements through an intermediate element.

[0029] like Figure 1-4 As shown, Figure 1 This is a schematic structural diagram of an exemplary embodiment of a quadrangular prism battery disclosed in the present invention. Figure 2 This is a schematic diagram of the structure of the winding core in an exemplary embodiment of the quadrangular prism battery disclosed in the present invention. Figure 3 is a cross-sectional view of a winding core in an exemplary embodiment of a quadrangular prism battery disclosed herein, Figure 4 This is a schematic diagram of the stacked structure of positive and negative electrodes in an exemplary embodiment of the quadrangular prism battery disclosed in the present invention. Figure 4 The positive and negative electrode sheets shown are schematic diagrams of the stacked structure after the winding core is unfolded.

[0030] like Figure 1-4 As shown, the quadrangular prism battery includes: a battery case 1, a winding core 2, the battery case 1 is a steel shell; the winding core 2 is at least partially located in the battery case 1, and the winding core 2 includes: a positive electrode sheet 21, a negative electrode sheet 22, and a separator 23. The positive electrode sheet 21 includes a positive electrode current collector layer 211 and a positive electrode active material layer 212 located on at least one side of the positive electrode current collector layer 211; the negative electrode sheet 22 includes a negative electrode current collector layer 221 and a negative electrode active material layer 222 located on at least one side of the negative electrode current collector layer 221; the separator 23 is located between the positive electrode sheet 21 and the negative electrode sheet 22. Among them, the negative electrode active material layer 222 is arranged beyond the positive electrode active material layer 212, and the dimension of the negative electrode active material layer 222 beyond the positive electrode active material layer 212 is greater than or equal to 0.8 mm, and the thermal conductivity of the battery case 1 is 15w / (m·k)-90w / (m·k).

[0031] The thermal conductivity of the steel shell is low, and the negative electrode sheet is an endothermic reaction during the charging process. In this exemplary embodiment, the negative electrode active material layer 222 is set beyond the positive electrode active material layer 212, and the negative electrode active material layer 222 can be closer to the battery housing 1. This setting can increase the speed at which the negative electrode sheet 22 absorbs heat from the outside of the battery housing 1, thereby improving the charging efficiency of the battery. At the same time, the size of the negative electrode active material layer 222 exceeding the positive electrode active material layer 212 is too small, and the battery charging efficiency is not significantly improved. In this exemplary embodiment, the size of the negative electrode active material layer 222 exceeding the positive electrode active material layer 212 is set to a suitable size, and this setting can improve the charging efficiency of the quadrangular prism battery. In addition, the steel shell is more easily corroded at high potentials. In this exemplary embodiment, the negative electrode active material layer 222 is set beyond the positive electrode active material layer 212, thereby reducing the risk of short circuit between the battery housing 1 and the positive electrode sheet 21, and further reducing the risk of corrosion of the battery housing 1.

[0032] In this exemplary embodiment, the dimension of the negative electrode active material layer 222 exceeding the positive electrode active material layer 212 can be equal to 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2 mm, 10 mm, 20 mm, 30 mm, 40 mm, 50 mm, 60 mm, 70 mm, 80 mm, 90 mm, 100 mm, etc. The thermal conductivity of the battery shell 1 can be 15w / (m·k), 20w / (m·k), 25w / (m·k), 30w / (m·k), 35w / (m·k), 40w / (m·k), 45w / (m·k), 50w / (m·k), 55w / (m·k), 60w / (m·k), 65w / (m·k), 70w / (m·k), 75w / (m·k), 80w / (m·k), 85w / (m·k), 90w / (m·k), etc.

[0033] In this exemplary embodiment, Figure 1-4 As shown, in the winding direction of the winding core 2, the winding tail end of the negative electrode sheet 22 is arranged beyond the winding tail end of the positive electrode sheet 21; and in the winding direction of the winding core 2, the dimension L1 of the winding tail end of the negative electrode sheet 22 exceeding the winding tail end of the positive electrode sheet 21 is 20mm-3000mm. For example, L1 can be equal to 20mm, 30mm, 40mm, 50mm, 60mm, 70mm, 80mm, 90mm, 100mm, 200mm, 300mm, 400mm, 500mm, 600mm, 700mm, 800mm, 900mm, 1000mm, 1100mm, 1200mm, 1300mm, 1400mm, 1500mm, 1600mm, 1700mm, 1800mm, 1900mm, 2000mm, 2100mm, 2200mm, 2300mm, 2400mm, 2500mm, 2600mm, 2700mm, 2800mm, 2900mm, 3000mm, etc. The excess negative electrode sheet 22 can be wrapped around the outside of the winding core 2. This setting can further reduce the risk of short circuit between the battery housing 1 and the positive electrode sheet 21, thereby further reducing the risk of corrosion of the battery housing. Among them, if L1 is too small, the effect of the negative electrode sheet 22 in improving the short circuit between the positive electrode sheet 21 and the battery housing 1 is not obvious; if L1 is too large, the ineffective volume of the winding core 2 is too large, which will affect the energy density of the quadrangular prism battery. This exemplary embodiment sets L1 to a suitable size, which can effectively reduce the risk of corrosion of the battery housing while ensuring the energy density of the battery.

[0034] It should be noted that in the winding direction of the winding core 2, the dimension by which the winding tail end of the negative electrode sheet 22 exceeds the winding tail end of the positive electrode sheet 21 is: after the winding core is flattened, the winding tail end of the negative electrode sheet 22 exceeds the winding tail end of the positive electrode sheet 21.

[0035] In this exemplary embodiment, Figure 1-4 As shown, the winding tail end of the negative electrode sheet 22 can be located on the maximum side of the winding core 2. On the one hand, the maximum side of the winding core 2 and the battery shell have a faster heat exchange speed, and this setting can facilitate the negative electrode sheet to absorb heat through the battery shell; on the other hand, the maximum side of the winding core 2 has a large expansion amount, and the negative electrode current collector layer 221 in the negative electrode sheet is generally a copper foil structure, and the negative electrode current collector layer 221 has a large strength. This setting can improve the problem of excessive expansion of the maximum side of the winding core 2.

[0036] In this exemplary embodiment, the quadrangular prism battery can be a lithium-ion battery, and the positive active material of the lithium-ion battery can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide, etc. The negative active material can be graphite, silicon, etc. The positive current collector layer can be aluminum foil, and the negative current collector layer can be copper foil. During charging, lithium ions are separated from the positive active material layer, move to the negative active material layer through the electrolyte, and the lithium ions are embedded in the interlayer gaps of the carbon material, completing the charging process of the battery. During discharge, lithium ions are separated from the negative active material layer, move to the positive active material layer through the electrolyte, and complete the discharge process of the battery. However, if the negative active material layer does not have a position to accept lithium ions, lithium ions will precipitate on the surface of the negative active material layer to form lithium dendrites, which can easily pierce the diaphragm and cause the battery to short-circuit.

[0037] In this exemplary embodiment, Figure 1-4As shown, the thickness of the separator 23 is 7 μm-20 μm, and the dimension of the negative electrode active material layer 222 beyond the positive electrode active material layer 212 is greater than or equal to 1.1 mm. For example, the dimension of the negative electrode active material layer 222 beyond the positive electrode active material layer 212 may be equal to 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2 mm, 10 mm, 20 mm, 30 mm, 40 mm, 50 mm, 60 mm, 70 mm, 80 mm, 90 mm, 100 mm, etc. The thickness of the separator 23 may be equal to 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, 20 μm, etc. If the thickness of the separator 23 is too large, the core 2 will not be able to dissipate heat quickly; if the thickness of the separator 23 is too small, the positive electrode sheet 21 and the negative electrode sheet 22 will be easily short-circuited due to lithium deposition on the negative electrode sheet. In this exemplary embodiment, the thickness of the separator 23 is set to a suitable size, which can ensure the heat dissipation speed of the core and reduce the risk of short-circuiting the positive and negative electrode sheets.

[0038] In this exemplary embodiment, Figure 1-4 As shown, at least one end of the negative electrode sheet 22 in the winding axis Y of the core 2 exceeds the positive electrode sheet 21, and the dimension L2 of the negative electrode sheet 22 exceeding the positive electrode sheet 21 in the winding axis Y of the core 2 is greater than or equal to 1mm. For example, the dimension L2 of the negative electrode sheet 22 exceeding the positive electrode sheet 21 in the winding axis Y of the core 2 can be equal to 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, etc. The setting of the negative electrode sheet 22 exceeding the positive electrode sheet 21 in the winding axis of the core 2 can improve the above-mentioned lithium deposition problem. In addition, the dimension of the negative electrode sheet 22 exceeding the positive electrode sheet 21 in the winding axis of the core 2 is too small, and the problem of lithium deposition still exists on the negative electrode sheet 22. In this exemplary embodiment, L2 is set to a suitable size, which can improve the lithium deposition problem of the negative electrode sheet.

[0039] In this exemplary embodiment, Figure 4 As shown, the negative electrode sheet 22 can be arranged beyond the positive electrode sheet 21 at both ends of the winding axis Y. It should be understood that in other exemplary embodiments, the negative electrode sheet 22 can also be arranged beyond the positive electrode sheet 21 only at one end of the winding axis.

[0040] In this exemplary embodiment, Figure 4As shown, in the winding direction of the winding core 2, the winding tail end of the diaphragm 23 is arranged beyond the winding tail end of the negative electrode sheet 22; wherein, the number of layers of the outermost diaphragm 23 of the winding core 2 beyond the outermost negative electrode sheet 22 is less than or equal to 3 layers. The number of layers of the outermost diaphragm 23 of the winding core 2 beyond the outermost negative electrode sheet 22 can be equal to 1 layer, 2 layers, 3 layers, etc. In this exemplary embodiment, the risk of short circuit between the positive and negative electrode sheets can be reduced by setting the diaphragm 23 beyond the positive and negative electrode sheets. At the same time, in this exemplary embodiment, the number of layers of the outermost diaphragm 23 of the winding core 2 beyond the outermost negative electrode sheet 22 is set to a smaller value. On the one hand, this setting can reduce the ineffective volume of the winding core, thereby improving the energy density of the battery; on the other hand, this setting can reduce the heat resistance of the diaphragm 23 to the negative electrode sheet 22 and the battery housing 1, thereby improving the heat conduction efficiency between the negative electrode sheet 22 and the battery housing.

[0041] In this exemplary embodiment, Figure 1-4 As shown, the thickness of the battery case 1 is 0.1mm-0.4mm. For example, the thickness of the battery case 1 can be equal to 0.1mm, 0.2mm, 0.3mm, 0.4mm, etc. If the thickness of the battery case 1 is too small, the strength of the battery case 1 is weak, and the battery case 1 is easily deformed; if the thickness of the battery case 1 is too large, the battery case 1 will occupy a larger space inside the battery case, which will result in a lower energy density of the quadrangular prism battery. This exemplary embodiment sets the thickness of the battery case 1 to a suitable size, which can not only ensure the energy density of the quadrangular prism battery, but also improve the overall strength of the battery case.

[0042] In this exemplary embodiment, the negative electrode current collector layer 221 is disposed beyond the positive electrode current collector layer 211. The arrangement of the negative electrode current collector layer 221 beyond the positive electrode current collector layer 211 can also improve the heat conduction efficiency between the negative electrode sheet and the battery case.

[0043] In this exemplary embodiment, Figure 4As shown, the winding core may also include a single positive electrode ear 24 and a single negative electrode ear 25, wherein the single positive electrode ear 24 is connected to the positive electrode current collector layer in the positive electrode sheet, for example, the single positive electrode ear 24 may be formed by cutting the positive electrode current collector material layer; and the single negative electrode ear 25 is connected to the negative electrode current collector layer in the negative electrode sheet, for example, the single negative electrode ear 25 may be formed by cutting the negative electrode current collector material layer. A plurality of single positive electrode ears 24 may be gathered to form a positive electrode ear of an integral structure, and a plurality of single negative electrode ears 25 may be gathered to form a negative electrode ear of an integral structure. The negative electrode current collector layer 221 may be coated with a negative electrode active material layer on its entire surface, and the positive electrode current collector layer 211 may be coated with a positive electrode active material layer on its entire surface. It should be understood that in other exemplary embodiments, the negative electrode current collector layer 221 may also be only partially coated with a negative electrode active material layer, and the positive electrode current collector layer 211 may also be only partially coated with a positive electrode active material layer 212. In addition, the negative electrode active material layer 222 may be coated on one side or both sides of the negative electrode collector layer 221 , and the positive electrode active material layer 212 may also be coated on one side or both sides of the positive electrode collector layer 211 .

[0044] In this exemplary embodiment, along the winding direction of the winding core 2, the dimension of the winding tail end of the negative electrode current collector layer 221 beyond the winding tail end of the positive electrode current collector layer 211 is 1 mm-1500 mm. For example, the dimension of the winding tail end of the negative electrode current collector layer 221 beyond the winding tail end of the positive electrode current collector layer 211 may be equal to 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 20 mm, 30 mm, 40 mm, 50 mm, 60 mm, 70 mm, 80 mm, 90 mm, 100 mm, 200 mm, 300 mm, 400 mm, 500 mm, 600 mm, 700 mm, 800 mm, 900 mm, 1000 mm, 1100 mm, 1200 mm, 1300 mm, 1400 mm, 1500 mm, etc. The excess negative current collector layer 221 can be wrapped around the outside of the winding core 2. This setting can further reduce the risk of short circuit between the battery case and the positive electrode sheet, thereby further reducing the risk of corrosion of the battery case. Among them, the size of the winding tail end of the negative current collector layer 221 exceeding the winding tail end of the positive current collector layer 211 is too small, and the effect of the negative current collector layer 221 on improving the short circuit between the positive electrode sheet 21 and the battery case 1 is not obvious; the size of the winding tail end of the negative current collector layer 221 exceeding the winding tail end of the positive current collector layer 211 is too large, which will increase the ineffective volume of the winding core, thereby affecting the energy density of the quadrangular prism battery. In this exemplary embodiment, the size of the winding tail end of the negative current collector layer 221 exceeding the winding tail end of the positive current collector layer 211 is set to a suitable size. This setting can effectively reduce the risk of corrosion of the battery case while ensuring the energy density of the battery.

[0045] It should be noted that, along the winding direction of the winding core 2, the dimension of the winding tail end of the negative electrode collector layer 221 exceeding the winding tail end of the positive electrode collector layer 211 is: after the winding core is flattened, the winding tail end of the negative electrode collector layer 221 exceeds the winding tail end of the positive electrode collector layer 211.

[0046] In this exemplary embodiment, Figure 1-4 As shown, the ratio of the dimension h1 of the positive electrode current collector layer 211 in the winding axis Y of the winding core 2 to the dimension h2 of the battery case 1 in the winding axis Y of the winding core 2 is greater than or equal to 0.85; h1 / h2 can be equal to 0.85, 0.86, 0.87, 0.88, 0.89, 0.90, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99, etc. And / or, the ratio of the dimension h3 of the negative electrode current collector layer 221 in the winding axis Y of the winding core 2 to the dimension h2 of the battery case 1 in the winding axis Y of the winding core 2 is greater than or equal to 0.85. h3 / h2 may be equal to 0.85, 0.86, 0.87, 0.88, 0.89, 0.90, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99, etc. This exemplary embodiment sets h1 / h2 and h3 / h2 to larger values, which can improve the energy density of the quadrangular prism battery.

[0047] In this exemplary embodiment, the quadrangular prism battery is a lithium iron phosphate battery or a lithium iron manganese phosphate battery. It should be understood that in other exemplary embodiments, the battery can also be a nickel-cadmium battery, a nickel-metal hydride battery, a lithium polymer battery, a sodium ion battery, a solid-state battery, etc.

[0048] This exemplary embodiment also provides a battery device, such as Figure 5 , which is a schematic diagram of the structure of an exemplary embodiment of the battery device of the present disclosure. The battery device comprises: the above-mentioned quadrangular prism battery 5, and a heating layer 3, wherein the heating layer 3 is arranged on the outer surface of the quadrangular prism battery 5, and the heating layer 3 is used to heat the quadrangular prism battery 5. The heating layer 3 can transfer its own heat to the negative electrode sheet 22, thereby improving the charging efficiency of the quadrangular prism battery.

[0049] In this exemplary embodiment, Figure 5As shown, the battery device also includes: a battery box 4, and a quadrangular prism battery 5 is located in the battery box 4. The heating layer 3 can be arranged on one side of the largest side of the quadrangular prism battery 5, and the thermal conductivity of the heating layer is greater than or equal to 0.4w / (m·k). For example, the thermal conductivity of the heating layer can be equal to 0.4w / (m·k), 0.5w / (m·k), 0.6w / (m·k), 0.7w / (m·k), 0.8w / (m·k), 0.9w / (m·k), 1w / (m·k), 2w / (m·k), 3w / (m·k), 4w / (m·k), 5w / (m·k), etc. This setting can increase the thermal conductivity between the heating layer 3 and the quadrangular prism battery 5, thereby further improving the charging efficiency of the quadrangular prism battery 5.

[0050] In other exemplary embodiments, the heating layer 3 may also be disposed on other sides of the quadrangular prism battery 5, for example, Figure 6 , which is a schematic diagram of the structure of another exemplary embodiment of the battery device of the present disclosure. The battery device also includes: a battery box 4, the battery box 4 includes a bottom plate 41; wherein the battery device includes a plurality of quadrangular prism batteries 5, the quadrangular prism batteries 5 include a first side surface 51, a second side surface 52, and a third side surface 53 that are interconnected and intersecting, the first side surface 51 is the largest side surface of the quadrangular prism battery, and the plurality of quadrangular prism batteries are distributed in a direction perpendicular to the first side surface 51, the second side surface 52 of the quadrangular prism battery is arranged facing the bottom plate 41, and the heating layer 3 is arranged on the side of the quadrangular prism battery located on the third side surface 53.

[0051] In other exemplary embodiments, the battery may be a square battery, that is, the battery may be a quadrangular prism-type battery. The quadrangular prism-type battery mainly refers to a battery having a prism-shaped appearance, but does not strictly limit whether each side of the prism must be a straight line in the strict sense, and the corners between the sides are not necessarily right angles, and may be arc transitions.

[0052] The battery may be a wound battery, that is, a first pole sheet, a second pole sheet with electrical properties opposite to the first pole sheet, and a diaphragm sheet arranged between the first pole sheet and the second pole sheet are wound to obtain a wound battery cell.

[0053] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing what is disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary technical means in the art that are not disclosed in the present disclosure. The specification and embodiments are to be considered merely as exemplary, and the true scope and spirit of the present disclosure are indicated by the claims.

[0054] The drawings in the present disclosure only relate to the structures involved in the present disclosure, and other structures may refer to the usual design. In the absence of conflict, the embodiments of the present disclosure and the features in the embodiments may be combined with each other to obtain new embodiments. It should be understood by those of ordinary skill in the art that the technical solutions of the present disclosure may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present disclosure, and should be included in the scope of the claims of the present disclosure.

[0055] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A quadrangular prism battery, characterized in that: The quadrangular prism battery comprises: A battery housing (1), wherein the battery housing (1) is a steel shell; A winding core (2) is at least partially located in the battery housing (1), and the winding core (2) comprises: A positive electrode sheet (21), the positive electrode sheet (21) comprising a positive electrode current collector layer (211) and a positive electrode active material layer (212) located on at least one side of the positive electrode current collector layer (211); A negative electrode sheet (22), the negative electrode sheet (22) comprising a negative electrode current collector layer (221) and a negative electrode active material layer (222) located on at least one side of the negative electrode current collector layer (221); A separator (23) located between the positive electrode sheet (21) and the negative electrode sheet (22); The negative electrode active material layer (222) is arranged beyond the positive electrode active material layer (212), the dimension of the negative electrode active material layer (222) beyond the positive electrode active material layer (212) is greater than or equal to 0.8 mm, and the thermal conductivity of the battery housing (1) is 15 w / (m·k)-90 w / (m·k).

2. The quadrangular prism battery according to claim 1, characterized in that: In the winding direction of the winding core (2), the winding tail end of the negative electrode sheet (22) is arranged beyond the winding tail end of the positive electrode sheet (21); Furthermore, in the winding direction of the winding core (2), the winding tail end of the negative electrode sheet (22) exceeds the winding tail end of the positive electrode sheet (21) by a dimension of 20 mm to 3000 mm.

3. The quadrangular prism battery according to claim 2, characterized in that: The winding tail end of the negative electrode sheet (22) is located on the largest side surface of the winding core (2).

4. The quadrangular prism battery according to claim 3, characterized in that: The thickness of the separator (23) is 7 μm-20 μm, and the dimension of the negative electrode active material layer (222) exceeding the positive electrode active material layer (212) is greater than or equal to 1.1 mm.

5. The quadrangular prism battery according to claim 1, characterized in that: At least one end of the negative electrode sheet (22) in the winding axis direction of the winding core (2) is arranged to extend beyond the positive electrode sheet (21); the dimension of the negative electrode sheet (22) extending beyond the positive electrode sheet (21) in the winding axis direction of the winding core (2) is greater than or equal to 1 mm.

6. The quadrangular prism battery according to claim 1, characterized in that: In the winding direction of the winding core (2), the winding tail end of the separator (23) is arranged beyond the winding tail end of the negative electrode sheet (22); The number of layers of the outermost separator (23) of the winding core (2) that exceeds the outermost negative electrode sheet (22) is less than or equal to 3.

7. The quadrangular prism battery according to any one of claims 1 to 6, characterized in that: The thickness of the battery casing (1) is 0.1 mm-0.4 mm.

8. The quadrangular prism battery according to any one of claims 1 to 6, characterized in that: The negative electrode current collector layer (221) is arranged beyond the positive electrode current collector layer (211), and along the winding direction of the winding core (2), the winding tail end of the negative electrode current collector layer (221) exceeds the winding tail end of the positive electrode current collector layer (211) by a dimension of 1 mm to 1500 mm.

9. The quadrangular prism battery according to any one of claims 1 to 6, characterized in that: The ratio of the size of the positive electrode current collector layer (211) in the winding axis of the winding core (2) to the size of the battery housing (1) in the winding axis of the winding core (2) is greater than or equal to 0.85; And / or, the ratio of the dimension of the negative electrode current collector layer (221) in the axial direction of the winding core (2) to the dimension of the battery housing (1) in the axial direction of the winding core (2) is greater than or equal to 0.

85.

10. A battery device, characterized in that: The battery device comprises: The quadrangular prism battery (5) according to any one of claims 1 to 9; A heating layer (3), the heating layer (3) being arranged on the outer surface of the quadrangular prism battery (5), the heating layer (3) being used to heat the quadrangular prism battery (5), the heating layer (3) being arranged on one side of the largest side of the quadrangular prism battery (5), and the thermal conductivity of the heating layer being greater than or equal to 0.4 w / (m·k).

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