Battery and battery device

Abstract

The utility model relates to the technical field of batteries, and provides a battery and a battery device, the battery comprises a shell and at least one roll core, and the shell is a quadrangular steel shell; the roll core comprises a roll core body, and at least part of the roll core body is located in the shell; the roll core body comprises a thickness direction, a height direction and a length direction, the thickness direction is perpendicular to the largest side face of the roll core body, the height direction is parallel to the winding axial direction of the roll core, and the length direction is perpendicular to the thickness direction and the height direction; the size of the roll core body in the thickness direction is d, the size of the roll core body in the length direction is a, and d / a is larger than or equal to 0.025 and smaller than or equal to 0.3. The battery provided by the utility model has relatively high heat dissipation efficiency.

Description

Technical Field

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

[0002] In the related art, the shell can use a steel shell instead of an aluminum shell to improve the strength of the shell. However, the thermal conductivity of the steel shell is low, and it is not easy for the core to dissipate heat through the steel shell, which can easily cause thermal runaway 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 battery, which can improve the technical problem of low heat dissipation efficiency of a winding core.

[0005] The battery comprises:

[0006] A shell, wherein the shell is a steel shell in the shape of a quadrangular prism;

[0007] at least one winding core, the winding core comprising a winding core body, the winding core body being at least partially located within the housing;

[0008] The core body includes a thickness direction, a height direction, and a length direction, wherein the thickness direction is perpendicular to the largest side of the core body, the height direction is parallel to the winding axis of the core, and the length direction is perpendicular to the thickness direction and the height direction;

[0009] The dimension of the core body in the thickness direction is d, the dimension of the core body in the length direction is a, and d / a is greater than or equal to 0.025 and less than or equal to 0.3.

[0010] The utility model can adjust the heat dissipation efficiency of the core through the shell by adjusting the size of d / a. When d / a is too small, the compacted core will have a sharper structure at its corner, which will result in a smaller contact area between the corner of the core and the shell, and the efficiency of the core dissipating heat through the shell is lower; when d / a is too large, the corner of the core has a larger thickness, and the contact degree between the corner of the core and the shell is lower relative to the straight part of the core, that is, the ratio of the contact area between the corner and the shell to the total outer surface area of ​​the corner is lower, and then the total contact degree between the core and the shell is lower, and the efficiency of the core dissipating heat through the shell is lower. The utility model sets d / a to a suitable size, and this setting can improve the heat dissipation efficiency of the core through the shell.

[0011] The utility model also provides a battery device, which includes the battery mentioned above.

[0012] 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

[0013] 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.

[0014] in:

[0015] Figure 1 It is a schematic structural diagram of an exemplary embodiment of a battery disclosed in the present invention;

[0016] Figure 2 This is a schematic diagram of the structure of a winding core in an exemplary embodiment of a battery disclosed herein;

[0017] Figure 3 A schematic structural diagram of a winding core in an exemplary embodiment of a battery disclosed herein from another perspective;

[0018] Figure 4 This is a schematic structural diagram of a winding core from another perspective in an exemplary embodiment of a battery disclosed herein.

[0019] Description of reference numerals:

[0020] 1. Shell; 2. Core; 21. Core body; 211. Corner portion; 212. Straight portion; 22. Tab; X, length direction; Y, height direction; Z, thickness direction. DETAILED DESCRIPTION

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] like Figure 1-4 As shown, Figure 1 It is a schematic structural diagram of an exemplary embodiment of a battery disclosed in the present invention. Figure 2 This is a schematic diagram of the structure of a winding core in an exemplary embodiment of a battery disclosed herein. Figure 3 This is a schematic structural diagram of a winding core from another perspective in an exemplary embodiment of the battery disclosed herein. Figure 4 This is a schematic structural diagram of a winding core from another perspective in an exemplary embodiment of a battery disclosed herein.

[0026] The battery includes: a shell 1 and at least one core 2, the shell 1 is a steel shell in the shape of a quadrangular prism; the core 2 includes a core body 21, and the core body 21 is at least partially located in the shell 1; the core body 21 includes a thickness direction Z, a height direction Y, and a length direction X, the thickness direction Z is perpendicular to the maximum side of the core body 21, the height direction Y is parallel to the winding axis of the core 2, and the length direction X is perpendicular to the thickness direction Z and the height direction Y; the size of the core body 21 in its thickness direction is d, and the size of the core body 21 in its length direction X is a, and d / a is greater than or equal to 0.025 and less than or equal to 0.3.

[0027] This exemplary embodiment can adjust the heat dissipation efficiency of the core through the shell by adjusting the size of d / a. When d / a is too small, the compacted core will have a sharper structure at its corner, which will result in a smaller contact area between the corner of the core and the shell, and the efficiency of the core dissipating heat through the shell is lower; when d / a is too large, the corner of the core has a larger thickness, and the contact degree between the corner of the core and the shell is lower relative to the straight part of the core, that is, the ratio of the contact area between the corner and the shell to the total outer surface area of ​​the corner is lower, and then the total contact degree between the core and the shell is lower, and the efficiency of the core dissipating heat through the shell is lower. This exemplary embodiment sets d / a to a suitable size, which can improve the heat dissipation efficiency of the core through the shell.

[0028] In this exemplary embodiment, d / a may be equal to 0.025, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.15, 0.2, 0.25, 0.3, etc.

[0029] In this exemplary embodiment, Figure 1-4 As shown, the core body 21 includes two corner portions 211 arranged opposite to each other in the length direction X thereof, and a straight portion 212 located between the two corner portions; the size of a single corner portion in the length direction X of the core body 21 is n, and the size of the straight portion 212 in the length direction X of the core body 21 is m, and 2n / m is greater than or equal to 0.03 and less than or equal to 0.3. For example, 2n / m can be equal to 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.15, 0.2, 0.25, 0.3, etc. If 2n / m is too large, the area where the largest side of the core and the shell 1 fit together is small, and the core 2 is not easy to dissipate heat through the shell 1; if 2n / m is too small, the compaction degree of the core 2 is insufficient, the gap between the adjacent layers of pole pieces in the core 2 is large, and the heat transfer speed between the adjacent layers of pole pieces is slow, which will affect the overall charge and discharge speed and thermal safety performance of the battery. This exemplary embodiment sets 2n / m to a suitable value, which can both ensure the charge and discharge speed of the battery and improve the thermal safety performance of the battery.

[0030] In this exemplary embodiment, the projection of the straight portion 212 along the height direction of the winding core body 21 is rectangular, and the corner portion has an arc-shaped outer side surface. Figure 1-4 As shown, d can be 10 mm-40 mm, for example, d can be equal to 10 mm, 20 mm, 30 mm, 40 mm, etc. In this exemplary embodiment, Figure 1-4As shown, a can be 120mm-650mm, for example, a can be equal to 120mm, 130mm, 140mm, 150mm, 200mm, 250mm, 300mm, 350mm, 400mm, 450mm, 500mm, 550mm, 600mm, 650mm, etc.

[0031] In this exemplary embodiment, Figure 1-4 As shown, the thermal conductivity of the shell 1 is 10w / m·k-90w / m·k. For example, the thermal conductivity of the shell 1 can be equal to 10w / m·k, 20w / m·k, 30w / m·k, 40w / m·k, 50w / m·k, 60w / m·k, 70w / m·k, 80w / m·k, 90w / m·k, etc. The smaller the thermal conductivity of the shell 1, the slower the heat dissipation rate of the core 2 through the shell; if the thermal conductivity of the shell 1 is too large, the steel shell is doped with too much material with high thermal conductivity, which will affect the overall strength of the shell. This exemplary embodiment sets the thermal conductivity of the shell 1 to an appropriate size, which can not only ensure the strength of the shell 1, but also increase the heat dissipation rate of the core through the shell.

[0032] The wall thickness of the shell 1 is less than or equal to 0.4 mm, for example, the wall thickness of the shell 1 can be equal to 0.4 mm, 0.3 mm, 0.2 mm, 0.1 mm, etc. The thinning of the shell improves the heat dissipation performance of the steel shell as a whole, and can increase the thickness of the shell and the battery body to ensure the overall energy density of the battery. Correspondingly, d / a is 0.05-0.3, for example, d / a can be equal to 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.15, 0.2, 0.25, 0.3, etc.

[0033] In this exemplary embodiment, Figure 1-4 As shown, the wall thickness of the housing 1 is 0.05mm-0.45mm. For example, the wall thickness of the housing 1 can be 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm, 0.12mm, 0.14mm, 0.16mm, 0.18mm, 0.2mm, 0.22mm, 0.24mm, 0.26mm, 0.28mm, 0.3mm, 0.32mm, 0.34mm, 0.36mm, 0.38mm, 0.4mm, 0.45mm, etc.

[0034] In this exemplary embodiment, the winding core 2 may include a positive electrode sheet, a negative electrode sheet, and a separator between the positive electrode sheet and the negative electrode sheet, and the ratio of the thermal conductivity of the shell 1 to the thickness of the separator is greater than or equal to 0.5W / (m·K·μm) and less than or equal to 18W / (m·K·μm). For example, the ratio of the thermal conductivity of the shell 1 to the thickness of the separator may be equal to 0.5W / (m·K·μm), 1W / (m·K·μm), 3W / (m·K·μm), 5W / (m·K·μm), 7W / (m·K·μm), 9W / (m·K·μm), 11W / (m·K·μm), 13W / (m·K·μm), 15W / (m·K·μm), 17W / (m·K·μm), 18W / (m·K·μm), etc. If the ratio of the thermal conductivity of the shell 1 to the thickness of the diaphragm is too small, not only the heat transfer rate between adjacent pole pieces inside the winding core is too slow, but also the speed at which the winding core dissipates heat through the shell is too slow, which can easily lead to thermal runaway of the battery; if the ratio of the thermal conductivity of the shell 1 to the thickness of the diaphragm is too large, short circuits between the positive and negative pole pieces inside the winding core are likely to occur, causing huge heat generation inside the battery, which can easily lead to thermal runaway of the battery and even cause the thermal runaway of the battery to spread. This exemplary embodiment sets the ratio of the thermal conductivity of the shell 1 to the thickness of the diaphragm to an appropriate size, which can further improve the thermal safety performance of the battery.

[0035] like Figure 1-4 As shown, the winding core 2 may also include a tab 22, and the winding core body includes a stacked positive electrode sheet, a negative electrode sheet, and a separator between the positive and negative electrode sheets. The positive electrode sheet includes a positive electrode collector and a positive electrode active material layer located on at least one side of the positive electrode collector, and the negative electrode sheet may include a negative electrode collector and a negative electrode active material layer located on at least one side of the negative electrode collector. The tab includes a positive tab and a negative tab. The positive tab is connected to the positive electrode collector in the positive electrode sheet, for example, the positive tab can be formed by cutting the positive electrode collector material layer; the negative tab is connected to the negative electrode collector in the negative electrode sheet, for example, the negative tab can be formed by cutting the negative electrode collector material layer. The positive electrode active material of the lithium-ion battery can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide, etc. The negative electrode active material can be graphite, silicon, etc. During charging, lithium ions are separated from the positive electrode active material, move to the negative electrode active material through the electrolyte, and the lithium ions are embedded in the interlayer gaps of the carbon material to complete the battery charging process. During discharge, lithium ions are separated from the negative electrode active material and move to the positive electrode active material through the electrolyte to complete the battery discharge process. However, if the negative electrode active material does not have a position to accept lithium ions, lithium ions will precipitate on the surface of the negative electrode active material to form lithium dendrites, which can easily pierce the diaphragm and cause a short circuit in the battery.

[0036] In this exemplary embodiment, the compaction density of the positive electrode sheet is greater than or equal to 3g / cm 3 And less than or equal to 4g / cm 3, d / a is greater than or equal to 0.03 and less than or equal to 0.28; and / or, the compaction density of the negative electrode sheet is greater than or equal to 1.3 g / cm 3 And less than or equal to 2g / cm 3 , d / a is greater than or equal to 0.03 and less than or equal to 0.29.

[0037] In this exemplary embodiment, the compaction density of the positive electrode sheet can be equal to 3g / cm 3 、3.5g / cm 3 , 4g / cm 3 Etc., correspondingly, d / a is greater than or equal to 0.03 and less than or equal to 0.28. For example, d / a can be equal to 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.15, 0.2, 0.25, 0.28, etc. In this exemplary embodiment, the core is too compacted, the thickness of the core body is small, and the overall energy density of the battery is low; the core is too loose, the thickness of the core body is large, and the core is easy to fall off (the active material layer falls off). This exemplary embodiment sets the compaction density of the positive electrode sheet and the d / a matching to a suitable range, so as to ensure the energy density of the battery and avoid the core falling off.

[0038] In this exemplary embodiment, the compaction density of the negative electrode sheet can be equal to 1.3 g / cm 3 , 1.5g / cm 3 , 2g / cm 3 Etc. d / a can be equal to 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.15, 0.2, 0.25, 0.28, 0.29, etc. The negative electrode sheet is not easy to fall off, the winding core can be pressed looser, and the corresponding winding core thickness can be larger.

[0039] In addition, if the compaction density of the positive and negative electrode sheets is too large, the stress concentration of the positive and negative electrode sheets is prone to lithium deposition; if the compaction density of the positive and negative electrode sheets is too small, the heat transfer speed inside the winding core is slow. This exemplary embodiment sets the compaction density of the positive and negative electrode sheets to an appropriate size, which can both increase the heat transfer speed inside the winding core and reduce the risk of lithium deposition in the winding core.

[0040] In this exemplary embodiment, the battery can be a lithium-ion battery, that is, the battery is a lithium 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.

[0041] It should be noted that a battery includes a cell and an electrolyte, and a battery is the smallest unit capable of performing electrochemical reactions such as charge / discharge. A cell refers to a unit formed by winding or laminating a stacked portion, wherein the stacked portion includes a first pole sheet, a separator, and a second pole sheet. When the first pole sheet is a positive pole sheet, the second pole sheet is a negative pole sheet. The polarities of the first pole sheet and the second pole sheet can be interchanged. The first pole sheet and the second pole sheet are coated with an active material.

[0042] In this exemplary embodiment, the quadrangular prism-shaped steel shell mainly refers to a prism-shaped outer shape, but it is not strictly limited 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 can be arc transitions.

[0043] 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.

[0044] The exemplary embodiment further provides a battery device, which is a battery module or a battery pack.

[0045] The battery module includes a plurality of batteries, and the batteries may be square batteries. The battery module may further include end plates and side plates, and the end plates and side plates are used to fix the plurality of batteries.

[0046] The battery pack includes a plurality of batteries and a box body, and the box body is used to fix the plurality of batteries.

[0047] It should be noted that the battery pack includes a battery, and the battery may be multiple, and the multiple batteries are arranged in the box. Among them, the multiple batteries can be installed in the box after forming a battery module. Alternatively, the multiple batteries can be directly arranged in the box, that is, there is no need to group the multiple batteries, and the box is used to fix the multiple batteries.

[0048] It should be noted that the battery device proposed in this exemplary embodiment can be used in various electrical devices, such as mobile phones, portable devices, laptops, various vehicles (such as battery cars, electric cars, etc.), ships, spacecraft, electric toys and electric tools, etc. Further, the above-mentioned spacecraft may include, for example, airplanes, rockets, space shuttles and spacecrafts. The above-mentioned electric toys may include, for example, fixed or mobile electric toys (such as game consoles, electric car toys, electric ship toys and electric airplane toys, etc.). The above-mentioned electric tools may include, for example, metal cutting electric tools, grinding electric tools, assembly electric tools and railway electric tools, specifically, for example, electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators and electric planers. It should be understood that in various possible embodiments that conform to the design concept of the utility model, the cylindrical battery or battery device proposed in the utility model is not limited to the above-described devices, but can also be applied to all devices using batteries. For the sake of simplicity, the various embodiments in this specification are described by taking vehicles as an example.

[0049] 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.

[0050] 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.

[0051] 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 battery, characterized in that: The battery comprises: A shell (1), wherein the shell (1) is a steel shell in the shape of a quadrangular prism; at least one winding core (2), the winding core (2) comprising a winding core body (21), the winding core body (21) being at least partially located inside the shell (1); The core body (21) comprises a thickness direction (Z), a height direction (Y), and a length direction (X), wherein the thickness direction (Z) is perpendicular to the largest side of the core body (21), the height direction (Y) is parallel to the winding axis of the core (2), and the length direction (X) is perpendicular to the thickness direction and the height direction (Y); The dimension of the winding core body (21) in the thickness direction is d, the dimension of the winding core body (21) in the length direction (X) is a, and d / a is greater than or equal to 0.025 and less than or equal to 0.

3.

2. The battery according to claim 1, characterized in that The winding core body (21) comprises two corner portions (211) arranged opposite to each other in the length direction (X) thereof, and a straight portion (212) located between the two corner portions (211); The size of a single corner portion (211) in the length direction (X) of the core body (21) is n, the size of the straight portion (212) in the length direction (X) of the core body (21) is m, and 2n / m is greater than or equal to 0.03 and less than or equal to 0.

3.

3. The battery according to claim 1, characterized in that d is 10mm-40mm.

4. The battery according to claim 1, characterized in that a is 120mm-650mm.

5. The battery according to claim 1, characterized in that The wall thickness of the shell (1) is less than or equal to 0.4 mm, and the d / a is 0.05-0.

3.

6. The battery according to claim 1, characterized in that The wall thickness of the shell (1) is 0.05 mm-0.45 mm.

7. The battery according to claim 1, characterized in that The winding core (2) comprises a positive electrode sheet, a negative electrode sheet, and a separator located between the positive electrode sheet and the negative electrode sheet, and the ratio of the thermal conductivity of the shell (1) to the thickness of the separator is greater than or equal to 0.5 W / (m·K·μm) and less than or equal to 18 W / (m·K·μm).

8. The battery according to claim 1, characterized in that The winding core (2) comprises a positive electrode sheet and a negative electrode sheet; The compaction density of the positive electrode sheet is greater than or equal to 3g / cm 3 And less than or equal to 4g / cm 3 , the d / a is greater than or equal to 0.03 and less than or equal to 0.28; And / or, the compaction density of the negative electrode sheet is greater than or equal to 1.3 g / cm 3 And less than or equal to 2g / cm 3 , the d / a is greater than or equal to 0.03 and less than or equal to 0.

29.

9. The battery according to any one of claims 1 to 7, characterized in that: The battery is a lithium battery.

10. A battery device, characterized in that: The battery device comprises the battery according to any one of claims 1 to 9.

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