Battery

Abstract

The utility model relates to the technical field of batteries, and provides a battery, which comprises a battery shell and a battery cover, the roll core is arranged in the battery shell, the roll core comprises a positive pole piece, a negative pole piece and a diaphragm, and the diaphragm is positioned between the positive pole piece and the negative pole piece; wherein in the winding direction of the winding core, the positive pole piece is provided with a first starting end and a first ending end, the negative pole piece is provided with a second starting end and a second ending end, and the size w of the first starting end exceeding the second starting end is 25mm-300mm, so that the overall heat dissipation rate of the battery can be improved, and the safe use performance of the battery is effectively improved.

Description

Technical Field

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

[0002] In the related art, a large amount of heat is generated during the use of the battery, and the heat inside the battery needs to be dissipated in time through the battery shell. However, due to the limitation of the heat dissipation capacity of the battery shell itself, the heat may not be dissipated in time, which will affect the safety performance of the battery. Utility Model Content

[0003] The utility model provides a battery to improve the use performance of the battery.

[0004] The utility model provides a battery, comprising:

[0005] a battery housing, the battery housing comprising steel;

[0006] The winding core is arranged in the battery housing, and the winding core comprises a positive electrode sheet, a negative electrode sheet and a diaphragm, and the diaphragm is located between the positive electrode sheet and the negative electrode sheet;

[0007] Among them, along the winding direction of the winding core, the positive electrode sheet has a first starting end and a first ending end, the negative electrode sheet has a second starting end and a second ending end, and the dimension w of the first starting end exceeding the second starting end is 25mm-300mm.

[0008] The battery of the utility model embodiment includes a battery housing and a winding core, and the winding core is arranged in the battery housing, and the heat generated in the winding core can be dissipated through the battery housing during the use of the battery. The winding core includes a positive electrode sheet, a negative electrode sheet and a diaphragm, and the diaphragm is located between the positive electrode sheet and the negative electrode sheet, thereby achieving insulation protection for the positive electrode sheet and the negative electrode sheet. By making the battery housing include steel, the heat dissipation rate of the steel is relatively low, and the discharge and lithium insertion of the positive electrode sheet is an exothermic reaction, and lower heat is required to facilitate the insertion rate of lithium ions. Since the positive main material is easy to lose activity under high temperature conditions, the heat required by the negative electrode sheet can be relatively large, so that the insertion and extraction rate of lithium ions in the negative electrode sheet is faster, and along the winding direction of the winding core, the positive electrode sheet has a first starting end and a first ending end, and the negative electrode sheet has a second starting end and a second ending end, and the dimension w of the first starting end exceeding the second starting end is 25mm-300mm, thereby improving the overall heat dissipation rate of the battery, thereby effectively improving the safe use performance of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] 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. Among them:

[0010] Figure 1 is a schematic structural diagram of a battery according to an exemplary embodiment;

[0011] Figure 2 is a schematic structural diagram of a battery winding core according to an exemplary embodiment;

[0012] Figure 3 is a schematic structural diagram of a positive electrode sheet and a negative electrode sheet of a battery according to an exemplary embodiment;

[0013] Figure 4 is a schematic structural diagram of a positive electrode sheet of a battery according to an exemplary embodiment;

[0014] Figure 5 is a schematic structural diagram of a positive electrode sheet and an insulating film of a battery according to an exemplary embodiment;

[0015] Figure 6 is a schematic diagram of a partial structure of a battery core according to an exemplary embodiment.

[0016] The following are the descriptions of the reference numerals:

[0017] 10. Battery case; 20. Winding core; 21. Positive electrode plate; 211. First starting end; 212. First ending end; 213. Positive current collector; 214. Positive active material layer; 22. Negative electrode plate; 221. Second starting end; 222. Second ending end; 23. Diaphragm; 30. Insulating film; 40. Post assembly. DETAILED DESCRIPTION

[0018] 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.

[0019] 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.

[0020] 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.

[0021] 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 another element (one or more) "upper", "lower", or "inner", "outer", it can not only be directly connected to the other (one or more) elements "upper", "lower", "inner", "outer", but also can be indirectly connected to the other (one or more) elements "upper", "lower", "inner", "outer" through an intermediate element.

[0022] An embodiment of the present utility model provides a battery, please refer to Figures 1 to 6 The battery includes: a battery shell 10, the battery shell 10 includes steel; a winding core 20, the winding core 20 is arranged in the battery shell 10, the winding core 20 includes a positive electrode sheet 21, a negative electrode sheet 22 and a separator 23, and the separator 23 is located between the positive electrode sheet 21 and the negative electrode sheet 22; wherein, along the winding direction of the winding core 20, the positive electrode sheet 21 has a first starting end 211 and a first ending end 212, the negative electrode sheet 22 has a second starting end 221 and a second ending end 222, and the dimension w1 of the first starting end 211 exceeding the second starting end 221 is 25mm-300mm.

[0023] A battery in one embodiment of the utility model includes a battery housing 10 and a winding core 20, wherein the winding core 20 is disposed in the battery housing 10, and the heat generated in the winding core 20 during the use of the battery can be dissipated through the battery housing 10. The winding core 20 includes a positive electrode sheet 21, a negative electrode sheet 22, and a separator 23, wherein the separator 23 is located between the positive electrode sheet 21 and the negative electrode sheet 22, thereby achieving insulation protection for the positive electrode sheet 21 and the negative electrode sheet 22. By making the battery housing 10 include steel, the heat dissipation rate of the steel is relatively low, and the discharge and lithium insertion of the positive electrode sheet 21 is an exothermic reaction, which requires lower heat and is beneficial to the insertion rate of lithium ions. Since the positive electrode main material is easy to lose its activity under high temperature conditions, the heat required by the negative electrode sheet 22 can be relatively large, so that the lithium ion insertion and extraction rate of the negative electrode sheet 22 is faster. Along the winding direction of the winding core 20, the positive electrode sheet 21 has a first starting end 211 and a first ending end 212, and the negative electrode sheet 22 has a second starting end 221 and a second ending end 222. The dimension w1 of the first starting end 211 exceeding the second starting end 221 is 25mm-300mm, thereby improving the overall heat dissipation rate of the battery, thereby effectively improving the safe use performance of the battery.

[0024] It should be noted that the battery housing 10 includes steel, and the heat dissipation rate of steel is slower than that of the aluminum shell in the related art. The battery housing 10 may include pure steel, carbon steel, nickel-plated steel, etc. The steel may include martensitic steel, austenitic steel, etc., which are not limited here.

[0025] Combination Figures 2 to 6 As shown, the winding core 20 includes a positive electrode sheet 21, a negative electrode sheet 22 and a separator 23, and the separator 23 is located between the positive electrode sheet 21 and the negative electrode sheet 22. The winding core 20 can be considered to be formed by winding. For example, the positive electrode sheet 21, the negative electrode sheet 22 and the separator 23 are wound on a winding core rod, thereby forming the winding core.

[0026] Along the winding direction of the winding core 20, the positive electrode sheet 21 has a first starting end 211 and a first ending end 212, and the negative electrode sheet 22 has a second starting end 221 and a second ending end 222. Figure 3 As shown, it can be considered that after the positive electrode sheet 21 and the negative electrode sheet 22 are laid flat, the first starting end 211 is arranged beyond the second starting end 221, that is, when winding, the positive electrode sheet 21 can be wound onto the winding core rod first. Figure 3As shown, the dimension of the first starting end 211 exceeding the second starting end 221 can be expressed as w1, that is, after the positive electrode sheet 21 and the negative electrode sheet 22 are unfolded, it can be considered that the positive electrode sheet 21 and the negative electrode sheet 22 are at least partially flattened, and w1 can be obtained by measuring the dimension between the first starting end 211 and the second starting end 221. Considering that the discharge and lithium insertion of the positive electrode sheet 21 is an exothermic reaction, lower heat is required to facilitate the insertion rate of lithium ions. After all, the active material of the positive electrode sheet 21 is easily deactivated under high temperature conditions, while the heat required by the negative electrode sheet 22 is generally larger. Therefore, by making the dimension w1 of the first starting end 211 exceeding the second starting end 221 by 25mm-300mm, that is, increasing the starting end size of the positive electrode sheet 21, the overall heat dissipation rate of the battery can be effectively improved, thereby improving the safety of the battery.

[0027] Along the winding direction of the winding core 20, the positive electrode sheet 21 has a first starting end 211 and a first ending end 212, and the positive electrode sheet 21 includes a positive electrode collector and a positive electrode active material layer, and the positive electrode active material layer is arranged on the positive electrode collector. Therefore, the first starting end 211 and the first ending end 212 are respectively the opposite ends of the positive electrode collector.

[0028] Correspondingly, along the winding direction of the winding core 20, the negative electrode sheet 22 has a second starting end 221 and a second ending end 222, and the negative electrode sheet 22 includes a negative electrode collector and a negative electrode active material layer, and the negative electrode active material layer is arranged on the negative electrode collector. Therefore, the second starting end 221 and the second ending end 222 are the opposite ends of the positive electrode collector, respectively.

[0029] The dimension w1 of the first starting end 211 beyond the second starting end 221 is 25 mm-300 mm, which means that the dimension w1 of the first starting end 211 of the positive electrode current collector beyond the second starting end 221 of the negative electrode current collector is 25 mm-300 mm.

[0030] The dimension w1 of the first starting end 211 beyond the second starting end 221 can be 25mm, 28mm, 30mm, 35mm, 40mm, 45mm, 50mm, 55mm, 60mm, 65mm, 70mm, 75mm, 80mm, 85mm, 90mm, 95mm, 100mm, 105mm, 110mm, 115mm, 120mm, 125mm, 130mm, 135mm, 140mm, 145mm, 150mm, 155mm, 160mm, 165mm, 170mm, 175mm, 180mm, 185mm, 186mm, 187mm, 188mm, 190mm, 201mm, 202mm, 203mm, 204mm, 205mm, 206mm, 207mm, 208mm 0mm, 145mm, 150mm, 155mm, 160mm, 165mm, 170mm, 175mm, 180mm, 185mm, 190mm, 195mm, 200mm, 205mm, 210mm, 215mm, 220mm, 230mm, 240mm, 250mm, 260mm, 270mm, 280mm, 290mm, 295mm or 300mm, etc.

[0031] The positive electrode active material layer includes positive electrode active materials, which are generally lithium-containing materials, such as lithium iron phosphate, lithium iron manganese phosphate, nickel cobalt manganese ternary metal oxide materials or nickel cobalt aluminum ternary metal oxide materials. The negative electrode active material layer includes negative electrode active materials, which may include graphite, hard carbon, soft carbon, mesophase carbon microspheres, silicon carbon and lithium titanate. The active material layer realizes the embedding or extraction of lithium ions.

[0032] The positive electrode collector and the negative electrode collector generally realize the transmission of battery current. Generally, the positive electrode collector is aluminum foil and the negative electrode collector is copper foil; alternatively, the positive electrode collector and the negative electrode collector can also be formed by a composite current collector of metal and non-metal. For example, the positive electrode collector includes a first polymer base film layer and a first metal layer arranged on the first polymer base film layer. The first polymer base film layer can use polyethylene terephthalate (PET) as the first polymer base film layer, and the first metal layer uses an aluminum layer. The negative electrode collector includes a second polymer base film layer and a second metal layer arranged on the second polymer base film layer. The second polymer base film layer can be polypropylene (OPP), and the second metal layer can be a copper layer.

[0033] In one embodiment, along the winding direction of the winding core 20, the second tail end 222 is arranged beyond the first tail end 212, thereby preventing the positive electrode sheet 21 from exceeding the negative electrode sheet 22, and further preventing the positive electrode sheet 21 from overlapping the battery shell 10. Considering that the battery shell 10 includes steel and the corrosion potential of the steel shell is high, there is a risk of corrosion after the battery shell 10 overlaps the shell.

[0034] The second end 222 is arranged beyond the first end 212 , that is, when the winding core 20 is wound, the positive electrode sheet 21 is wound first, and the negative electrode sheet 22 is wound later.

[0035] In one embodiment, the second end 222 exceeds the first end 212 by a dimension w2 of 30 mm to 350 mm, which can reduce the risk of the positive electrode sheet 21 overlapping the battery housing 10 and avoid affecting the continuous winding of the winding core 20 .

[0036] Combination Figure 3 As shown, the dimension of the second end 222 exceeding the first end 212 can be expressed as w2, that is, after the positive electrode sheet 21 and the negative electrode sheet 22 are laid flat, the dimension of the second end 222 exceeding the first end 212 can be expressed as w2.

[0037] The dimension w2 of the second end 222 exceeding the first end 212 is 30 mm-350 mm, which means that the dimension w2 of the second end 222 of the negative electrode current collector exceeds the first end 212 of the positive electrode current collector by 30 mm-350 mm.

[0038] The dimension w2 of the second end 222 beyond the first end 212 may be 30mm, 35mm, 40mm, 45mm, 50mm, 55mm, 60mm, 65mm, 70mm, 75mm, 80mm, 85mm, 90mm, 95mm, 100mm, 105mm, 110mm, 115mm, 120mm, 125mm, 130mm, 135mm, 140mm, 145mm, 150mm, 155mm, 160mm, 165mm, 170mm, 175mm, 180mm, 185mm, 190mm, 200mm, 210mm, 215mm, 220mm, 225mm, 230mm, 235mm, 240mm, 250mm, 255mm, 260mm, 270mm, 275mm, 280mm, 285mm, 290mm, 300mm, 350mm, 360mm, 370mm, 380mm, 390mm, 400mm, 410mm, 420mm, 430mm, 440mm, 450mm, 460mm, 470mm, 480mm, 490mm, 500mm, 510mm, 510mm, 520mm, 530mm, 530mm, 540mm, 550mm, 560mm, 570mm, 580mm 60mm, 165mm, 170mm, 175mm, 180mm, 185mm, 190mm, 195mm, 200mm, 205mm, 210mm, 215mm, 220mm, 230mm, 240mm, 250mm, 260mm, 270mm, 280mm, 290mm, 295mm, 300mm, 310mm, 320mm, 330mm, 340mm, 345mm or 350mm, etc.

[0039] In one embodiment, the second tail end 222 exceeds the first tail end 212 by a dimension w2, and w1 / w2 is 0.8-1.2, which can reduce the risk of overlap between the positive electrode plate 21 and the battery casing 10 and avoid the problem of low efficiency when the core 20 is formed.

[0040] The ratio of the dimension w1 of the first starting end 211 exceeding the second starting end 221 to the dimension w2 of the second ending end 222 exceeding the first ending end 212 is too large, and the negative electrode plate 22 has insufficient relative lithium embedding space, which poses a risk of lithium plating, and there is a greater risk of overlap between the positive electrode plate 21 and the battery case 10; the ratio of the dimension w1 of the first starting end 211 exceeding the second starting end 221 to the dimension w2 of the second ending end 222 exceeding the first ending end 212 is too small, and the positive electrode plate 21 and the negative electrode plate 22 are too unbalanced, making it difficult to achieve continuous winding of the core 20, and the current collector needs to be cut to produce a large amount of metal shavings, which is not conducive to ensuring the safety performance of the core 20.

[0041] The ratio of the dimension w1 of the first starting end 211 beyond the second starting end 221 to the dimension w2 of the second ending end 222 beyond the first ending end 212 may be 0.8, 0.82, 0.85, 0.88, 0.9, 0.92, 0.95, 0.98, 1, 1.02, 1.05, 1.08, 1.1, 1.12, 1.15, 1.18 or 1.2, etc. In one embodiment, as Figure 5 As shown, the positive electrode plate 21 includes a positive electrode collector 213 and a positive electrode active material layer 214, and the positive electrode active material layer 214 is arranged on the positive electrode collector 213. The battery also includes: an insulating film 30, and the insulating film 30 is arranged on the positive electrode active material layer 214. Along the winding direction of the core 20, the size L1 of the insulating film 30 is 30mm-350mm, which can ensure the overall heat dissipation efficiency of the core 20, and ensure that the core 20 has a reliable lithium insertion space, thereby improving the overall safety performance of the battery.

[0042] Combination Figure 5 As shown, the positive electrode plate 21 includes a positive electrode current collector 213 and a positive electrode active material layer 214, and the insulating film 30 is arranged on the positive electrode active material layer 214, thereby avoiding the risks of stress concentration and slow ion transfer rate causing the core to break or the electrode plate lithium plating causing the core 20 to short-circuit.

[0043] Along the winding direction of the winding core 20, the size L1 of the insulating film 30 is 30 mm-350 mm, that is, after the positive electrode sheet 21 is flattened, the size of the insulating film 30 can be expressed as L1, such as Figure 5 That is, the positive electrode sheet 21, the negative electrode sheet 22 and the separator 23 are disassembled from the winding core 20, and the positive electrode sheet 21 provided with the insulating film 30 is laid flat. At this time, the insulating film 30 is also basically in a flat state. If the insulating film 30 is wrinkled due to disassembly or other reasons, the insulating film 30 also needs to be laid flat, so as to measure the size L1 of the insulating film 30.

[0044] The size L1 of the insulating film 30 may be 30 mm, 35 mm, 40 mm, 45 mm, 50 mm, 55 mm, 60 mm, 65 mm, 70 mm, 75 mm, 80 mm, 85 mm, 90 mm, 95 mm, 100 mm, 105 mm, 110 mm, 115 mm, 120 mm, 125 mm, 130 mm, 135 mm, 140 mm, 145 mm, 150 mm, 155 mm, 160 mm, 166 mm, 170 mm, 171 mm, 172 mm, 173 mm, 174 mm, 176 mm, 177 mm, 178 mm, 179 mm, 180 mm, 181 mm, 182 mm, 183 mm, 184 mm, 186 mm, 187 mm, 188 mm, 189 mm, 190 mm, 191 mm, 192 mm, 193 mm, 194 mm, 195 mm, 5mm, 170mm, 175mm, 180mm, 185mm, 190mm, 195mm, 200mm, 205mm, 210mm, 215mm, 220mm, 230mm, 240mm, 250mm, 260mm, 270mm, 280mm, 290mm, 295mm, 300mm, 310mm, 320mm, 330mm, 340mm, 345mm or 350mm, etc.

[0045] In one embodiment, Figure 4 As shown, the positive electrode sheet 21 includes a positive current collector 213 and a positive active material layer 214. The positive active material layer 214 is arranged on the positive current collector 213. The positive current collector 213 forms a first starting end 211. Along the winding direction of the core 20, the first starting end 211 and one end of the positive active material layer 214 facing the first starting end 211 are spaced apart, that is, the winding starting part of the positive current collector 213 may not be provided with the positive active material layer 214, which can not only reduce the risk of insufficient lithium embedding space and improve the overall safety performance of the battery, but also facilitate the heat dissipation of the core 20.

[0046] In one embodiment, the distance L2 between the first starting end 211 and one end of the positive electrode active material layer 214 toward the first starting end 211 is 28mm-280mm, which can avoid insufficient lithium embedding space in the winding core 20 and improve the overall safety performance of the battery, and can also avoid the distance L2 being too large to affect the overall energy density of the battery.

[0047] Along the winding direction of the winding core 20, the distance between the first starting end 211 and the end of the positive electrode active material layer 214 facing the first starting end 211 is L2, that is, after the positive electrode sheet 21 is flattened, the distance between the first starting end 211 and the end of the positive electrode active material layer 214 facing the first starting end 211 can be expressed as L2, as shown in FIG. Figure 4 shown.

[0048] The distance L2 between the first starting end 211 and the end of the positive electrode active material layer 214 facing the first starting end 211 can be 28mm, 30mm, 35mm, 40mm, 45mm, 50mm, 55mm, 60mm, 65mm, 70mm, 75mm, 80mm, 85mm, 90mm, 95mm, 100mm, 105mm, 110mm, 115mm, 120mm, 125mm, 130mm, 135mm, 140mm, 145mm, 150mm, 155mm, 160mm, 165mm, 170mm, 175mm, 180mm, 185mm, 190mm, 195mm, 200mm, 205mm, 210mm, 215mm, 220mm, 230mm, 240mm, 250mm, 260mm, 270mm or 280mm, etc.

[0049] In one embodiment, the wall thickness of the battery housing 10 is ≤0.45 mm, so that the overall weight of the battery housing 10 can be effectively controlled, the energy density of the battery can be improved, and the heat dissipation capacity of the battery can also be increased through the thinner battery housing 10 .

[0050] In one embodiment, the length of the battery housing 10 is ≥150 mm, thereby ensuring the capacity of the battery, and further facilitating subsequent battery grouping, thereby improving the battery grouping capability.

[0051] The length of the battery housing 10 may be 150 mm, 155 mm, 158 mm, 160 mm, 165 mm, 168 mm, 170 mm, 175 mm, 178 mm, 180 mm, 185 mm, 188 mm, 190 mm, 195 mm, 198 mm or 200 mm, etc.

[0052] In one embodiment, the wall thickness of the battery housing 10 is ≥0.05 mm, thereby ensuring that the battery housing 10 has a certain structural strength, thereby improving the safe use performance of the battery.

[0053] It should be noted that the wall thickness of the battery housing 10 can be 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm, 0.11mm, 0.12mm, 0.13mm, 0.14mm, 0.15mm, 0.16mm, 0.17mm, 0.18mm, 0.19mm, 0.2mm, 0.21mm, 0.22mm, 0.23mm, 0. 24mm, 0.25mm, 0.26mm, 0.27mm, 0.28mm, 0.29mm, 0.3mm, 0.31mm, 0.32mm, 0.33mm, 0.34mm, 0.35mm, 0.36mm, 0.37mm, 0.38mm, 0.39mm, 0.4mm, 0.41mm, 0.42mm, 0.43mm, 0.44mm or 0.45mm, etc.

[0054] In one embodiment, the thickness of the diaphragm 23 is ≤18 μm, which can not only prevent the diaphragm 23 from occupying a large space and affecting the energy density of the battery, but also ensure the heat dissipation capacity of the core 20 .

[0055] The thickness of the diaphragm 23 may be 18 μm, 17 μm, 16 μm, 15 μm, 14 μm, 13 μm, 12 μm, 11 μm, or 10 μm, etc.

[0056] In one embodiment, the battery is a ternary lithium battery, which can effectively improve the safe use performance of the battery.

[0057] The battery is a ternary lithium battery, that is, the battery can be a nickel-cobalt-manganese ternary lithium battery.

[0058] In one embodiment, the battery is a lithium iron phosphate battery. On the basis of ensuring the battery capacity, the safety of the lithium iron phosphate battery will be relatively higher.

[0059] It should be noted that the lithium iron phosphate positive electrode material of the lithium iron phosphate battery can be compounded with a ternary positive electrode material. At this time, when the proportion of the lithium iron phosphate positive electrode material is greater than the ternary positive electrode material, the battery type can still be considered a lithium iron phosphate battery. The ternary positive electrode material of the ternary lithium battery can be compounded with a lithium iron phosphate positive electrode material. At this time, when the proportion of the ternary positive electrode material is greater than the lithium iron phosphate positive electrode material, the battery type can still be considered a ternary lithium battery.

[0060] In one embodiment, the positive electrode plate 21 includes aluminum, the negative electrode plate 22 includes copper, and the first starting end 211 of the aluminum exceeds the second starting end 221 of the copper, thereby ensuring the overall heat dissipation rate of the battery.

[0061] It should be noted that the battery includes a cell and an electrolyte, which 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, the stacked portion including 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.

[0062] In one embodiment, the battery may be a quadrangular prism battery. A quadrangular prism battery mainly refers to a battery having a prism 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.

[0063] The battery can be a laminated battery, which is not only convenient to group, but also can be processed to obtain a longer battery. Specifically, the battery cell is a laminated battery cell, which has a first pole piece stacked on top of each other, a second pole piece with electrical properties opposite to the first pole piece, and a diaphragm sheet arranged between the first pole piece and the second pole piece, so that multiple pairs of first pole pieces and second pole pieces are stacked to form a laminated battery cell.

[0064] Alternatively, 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.

[0065] In one embodiment, the battery may be a cylindrical battery, or the battery may be a hexagonal prism battery. The battery may be a wound battery, that is, a first pole piece, a second pole piece with electrical properties opposite to the first pole piece, and a diaphragm sheet disposed between the first pole piece and the second pole piece are wound to obtain a wound battery cell.

[0066] In one embodiment, Figure 1 As shown, the battery further includes a pole assembly 40 , which can be disposed on the battery housing 10 . There can be two pole assemblies 40 , and the two pole assemblies 40 can be electrically connected to the positive electrode tab and the negative electrode tab of the winding core 20 , respectively.

[0067] An embodiment of the utility model further provides a battery pack, comprising the above-mentioned battery.

[0068] The battery of the battery pack of one embodiment of the utility model comprises a battery case 10 and a winding core 20, wherein the winding core 20 is disposed in the battery case 10, and the heat generated in the winding core 20 during the use of the battery can be dissipated through the battery case 10. The winding core 20 comprises a positive electrode sheet 21, a negative electrode sheet 22 and a separator 23, wherein the separator 23 is located between the positive electrode sheet 21 and the negative electrode sheet 22, thereby achieving insulation protection for the positive electrode sheet 21 and the negative electrode sheet 22. By making the battery housing 10 include steel, the heat dissipation rate of the steel is relatively low, and the discharge and lithium insertion of the positive electrode sheet 21 is an exothermic reaction, which requires lower heat and is beneficial to the insertion rate of lithium ions. The heat required by the negative electrode sheet 22 can be relatively large. Along the winding direction of the winding core 20, the positive electrode sheet 21 has a first starting end 211 and a first ending end 212, and the negative electrode sheet 22 has a second starting end 221 and a second ending end 222. The dimension w1 of the first starting end 211 exceeding the second starting end 221 is 25mm-300mm, thereby improving the overall heat dissipation rate of the battery, thereby effectively improving the safety performance of the battery.

[0069] In one embodiment, the battery pack is a battery module or a battery pack.

[0070] The battery module includes a plurality of batteries, and the battery module may further include an end plate and a side plate, and the end plate and the side plate are used to fix the plurality of batteries.

[0071] It should be noted that multiple batteries can be arranged in a battery box after forming a battery module, and multiple batteries can be fixed by end plates and side plates. Multiple batteries can be directly arranged in the battery box, that is, there is no need to group multiple batteries, in which case the end plates and side plates can be removed.

[0072] Those skilled in the art will readily come up with other embodiments of the present disclosure after considering the specification and practicing the utility model disclosed herein. The present disclosure is intended to cover any variation, use or adaptation of the present utility model, which follows the general principles of the present disclosure and includes common knowledge or customary technical means in the art that are not disclosed in the present disclosure. The specification and example embodiments are to be regarded as exemplary only, and the true scope and spirit of the present disclosure are indicated by the appended claims.

[0073] It should be understood that the present disclosure is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from its scope. The scope of protection of the present disclosure is limited only by the appended claims.

Claims

1. A battery, characterized in that: include: A battery housing (10), the battery housing (10) comprising steel; A winding core (20), the winding core (20) being arranged in the battery housing (10), the winding core (20) comprising a positive electrode sheet (21), a negative electrode sheet (22) and a diaphragm (23), the diaphragm (23) being located between the positive electrode sheet (21) and the negative electrode sheet (22); Wherein, along the winding direction of the winding core (20), the positive electrode sheet (21) has a first starting end (211) and a first ending end (212), and the negative electrode sheet (22) has a second starting end (221) and a second ending end (222), and the dimension w1 of the first starting end (211) exceeding the second starting end (221) is 25 mm-300 mm.

2. The battery according to claim 1, characterized in that Along the winding direction of the winding core (20), the second tail end (222) is arranged beyond the first tail end (212).

3. The battery according to claim 2, characterized in that The dimension w2 of the second end (222) beyond the first end (212) is 30 mm-350 mm.

4. The battery according to claim 2, characterized in that The second end (222) exceeds the first end (212) by a dimension w2, and w1 / w2 is 0.8-1.

2.

5. The battery according to any one of claims 1 to 4, characterized in that The positive electrode plate (21) comprises a positive electrode current collector (213) and a positive electrode active material layer (214), wherein the positive electrode active material layer (214) is arranged on the positive electrode current collector (213), and the battery further comprises: An insulating film (30), wherein the insulating film (30) is disposed on the positive electrode active material layer (214), and along the winding direction of the winding core (20), a size L1 of the insulating film (30) is 30 mm to 350 mm.

6. The battery according to any one of claims 1 to 4, characterized in that The positive electrode sheet (21) comprises a positive electrode current collector (213) and a positive electrode active material layer (214); the positive electrode active material layer (214) is arranged on the positive electrode current collector (213); the positive electrode current collector (213) forms the first starting end (211); along the winding direction of the winding core (20), the first starting end (211) is spaced from one end of the positive electrode active material layer (214) facing the first starting end (211); Wherein, a distance L2 between the first starting end (211) and an end of the positive electrode active material layer (214) facing the first starting end (211) is 28 mm-280 mm.

7. The battery according to any one of claims 1 to 4, characterized in that The wall thickness of the battery housing (10) is ≤0.45 mm.

8. The battery according to any one of claims 1 to 4, characterized in that The length of the battery housing (10) is ≥150 mm, and / or the wall thickness of the battery housing (10) is ≥0.05 mm.

9. The battery according to any one of claims 1 to 4, characterized in that The thickness of the separator (23) is ≤18 μm, and / or the positive electrode plate (21) comprises aluminum, and the negative electrode plate (22) comprises copper.

10. The battery according to any one of claims 1 to 4, characterized in that The battery is a ternary lithium battery, or the battery is a lithium iron phosphate battery, or the battery is a quadrangular prism battery.

Images