Pole core, battery cell, battery device, and electric device

Abstract

The application provides an electrode core, a battery monomer, a battery device and an electric equipment, and relates to the technical field of batteries. The electrode core comprises negative electrode sheets, separators and positive electrode sheets. The negative electrode sheets, the separators and the positive electrode sheets are alternately stacked along a first direction. Along a second direction, the edges of at least one same-side negative electrode sheet and the edges of the separators all exceed the edges of the positive electrode sheets. The exceeding parts of the negative electrode sheets and the separators are close to each other, and the second direction intersects the first direction. According to the electrode core provided in the application, the edges of the negative electrode sheets and the separators are packaged by folding and overlapping, which can reduce the internal resistance, avoid sharp bending of the edges, reduce the falling and sliding of the coating, and thus ensure the performance of the battery.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, and in particular to a pole core, a battery monomer, a battery device and a power consumption equipment. BACKGROUND

[0002] At present, in order to avoid the risk of mispositioning of the edge of the pole piece of the battery in the process of lamination or winding, leading to lithium charging short circuit, a negative overhang positive design concept is adopted, that is, the size of the negative electrode is wider than that of the positive electrode in the four directions, and there is a so-called overhang area. In the related art, the area overhanging on the pole piece is encapsulated and insulated.

[0003] However, encapsulation and insulation will increase the current collector and the internal resistance of the battery, affecting the power performance of the battery. UTILITY MODEL CONTENT

[0004] Therefore, the present application provides a pole core, a battery monomer, a battery device and a power consumption equipment to solve the problem that the encapsulation and insulation of the edge of the pole core of the existing battery will increase the current collector and the internal resistance of the battery.

[0005] In a first aspect, the present application provides a pole core, comprising a plurality of negative pole pieces, a plurality of separation layers and a plurality of positive pole pieces.

[0006] Each negative pole piece, each separation layer and each positive pole piece is alternately stacked along a first direction, and along a second direction, the edge of at least one same side negative pole piece and the edge of the separation layer both exceed the edge of the positive pole piece.

[0007] The overhanging part of each negative pole piece and each separation layer is close to each other, and sequentially forms a folding section and an overlapping section along the second direction, and the second direction intersects the first direction.

[0008] In a possible implementation, along the first direction, the angle between the surface of the folding section and the second direction is less than or equal to 80° and greater than 0°.

[0009] In a possible implementation, along the first direction, the angle between the surface of the folding section and the second direction is greater than or equal to 45°.

[0010] In a possible implementation, along the first direction, the length of the folding section along the second direction is a first relative length, the sum of the lengths of the folding section and the overlapping section along the second direction is a second relative length, and the ratio of the first relative length to the second relative length is greater than or equal to 0.4 and less than 1.

[0011] In a possible implementation, along the second direction, the length of the overhanging part is an initial length, and the ratio of the first relative length to the initial length is greater than or equal to 0.3 and less than 1.

[0012] In a possible implementation, the negative electrode sheets and the separator layers on both sides are symmetrically arranged along the first direction.

[0013] In a possible implementation, along the first direction, the thickness of the overlap section of each negative electrode sheet, each separator layer and each positive electrode sheet is a second thickness, and the thickness of the overlap section of the overlap section at the joint with the overlap section is a first thickness, the ratio of the first thickness to the second thickness is greater than or equal to 0.33 and less than 1.

[0014] In a possible implementation, the overlap section has a surface, and the angle between the surface and the second direction is less than or equal to 5° and greater than or equal to 0°.

[0015] In a possible implementation, the separator layer comprises a solid-state electrolyte layer.

[0016] In a possible implementation, along the second direction, the length of the separator layer is equal to the length of the negative electrode sheet.

[0017] In a possible implementation, along the first direction, the outermost layers of the jelly-roll are negative electrode sheets.

[0018] In a second aspect, the present application also provides a battery cell, comprising a shell and any one of the jelly-rolls provided in the first aspect, wherein the jelly-roll is arranged in the shell.

[0019] In a third aspect, the present application also provides a battery device, comprising a box body and at least one battery cell provided in the second aspect, wherein the battery cell is arranged in the box body.

[0020] In a fourth aspect, the present application also provides a power consumption device, comprising a device body, and the device body is provided with a battery cell provided in the second aspect.

[0021] Alternatively, the device body is provided with a battery device provided in the third aspect.

[0022] In the jelly-roll, the battery cell, the battery device and the power consumption device provided in the present application, the jelly-roll comprises a plurality of negative electrode sheets, a plurality of separator layers and a plurality of positive electrode sheets, each negative electrode sheet, each separator layer and each positive electrode sheet are alternately stacked along a first direction, and at least one edge of the negative electrode sheet and at least one edge of the separator layer on the same side are arranged to be beyond the edge of the positive electrode sheet along a second direction, the overlapping part of each negative electrode sheet and each separator layer is arranged to be close to each other along the second direction, and the overlap section and the overlap section are sequentially formed along the second direction, and the second direction intersects the first direction.

[0023] Therefore, the jelly-roll provided in the present application can reduce the internal resistance by packaging the edge of each negative electrode sheet and each separator layer through the overlap and the overlap, avoid the sharp bending of the edge of the negative electrode sheet, reduce the falling and sliding of the electrode sheet, and thus ensure the performance of the battery. BRIEF DESCRIPTION OF DRAWINGS

[0024] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a first state diagram of the electrode core provided in an embodiment of this application;

[0026] Figure 2 This is a second state diagram of the electrode core provided in an embodiment of this application.

[0027] Figure label:

[0028] 100: Negative electrode plate;

[0029] 110: Ontology section;

[0030] 101: Closing section;

[0031] 102: Overlap section;

[0032] 200: Separator layer;

[0033] 300: Positive electrode plate. Detailed Implementation

[0034] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of methods and apparatus consistent with some aspects of this application as detailed in the appended claims.

[0035] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a particular order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0036] As mentioned in the background section, the unreasonable size design of the existing battery overhang area can intensify the bending of the battery tab edge, leading to the detachment and sliding of the coating, and the direct contact between the positive and negative electrodes, thereby increasing the risk of short circuit. To solve this problem, in the related art, the overhanging part of the negative electrode is encapsulated and insulated by using a polymer to reduce the risk of short circuit. There are also special structure designs that make the positive active material layer present a trapezoidal design, that is, the outer edge of the current collector is more outward, and the solid electrolyte layer is more inward than the outer edge, thereby reducing the risk of short circuit. There are also methods of processing the boundary edge of the positive tab to form a certain inactive area to reduce short circuit. However, encapsulating and insulating the overhanging area by using a polymer can increase the internal resistance of the current collector and the battery, affecting the power performance of the battery. At the same time, due to the low modulus and high deformation characteristics of the polymer itself, there is still a risk of rupture and short circuit during the high-pressure forming process. The use of tab coating trapezoidal design can greatly increase the manufacturing difficulty and stability of the tab, and the use of edge inactivation scheme can increase the additional process and cause additional material waste. Laser ablation inactivation can also introduce molten beads, thereby also increasing the risk of short circuit.

[0037] To solve the above problems in the prior art, the application provides a pole core, a battery monomer, a battery device and an electric equipment. The pole core provided by the application comprises a plurality of negative tabs, a plurality of separation layers and a plurality of positive tabs. The negative tabs, the separation layers and the positive tabs are alternately stacked along a first direction. The edges of at least one negative tab and the edges of the separation layers on the same side all exceed the edges of the positive tabs along a second direction. The overhanging parts of the negative tabs and the separation layers are close to each other, and the overhanging parts sequentially form a folding section and an overlapping section along the second direction. The second direction intersects the first direction, that is, the edges of the negative tabs and the edges of the separation layers are encapsulated by folding and overlapping, which can reduce the internal resistance, avoid the sharp bending of the edges of the negative tabs, reduce the detachment and sliding of the coating, and thus ensure the performance of the battery.

[0038] The technical solutions of the application will be described in detail below with specific examples. The following specific examples can be combined with each other, and the same or similar concepts or processes can not be described in detail in some examples.

[0039] In a first aspect, referring to Figures 1-2 The pole core provided by the embodiments of the application comprises a plurality of negative tabs 100, a plurality of separation layers 200 and a plurality of positive tabs 300.

[0040] The negative tabs 100, the separation layers 200 and the positive tabs 300 are alternately stacked along a first direction. The edges of at least one negative tab 100 and the edges of the separation layers 200 on the same side all exceed the edges of the positive tabs 300 along a second direction.

[0041] The extended portions of each negative electrode 100 and each separator layer 200 move closer to each other and form a closing section 101 and an overlapping section 102 in sequence along the second direction, which intersects with the first direction.

[0042] In this embodiment, the negative electrode 100, the separator layer 200, and the positive electrode 300 are all generally rectangular sheet or plate-like structures. The edges of the negative electrode 100 and the separator layer 200 extend beyond the edge of the positive electrode 300. That is, the size of the negative electrode 100 and the separator layer 200 is larger than the size of the positive electrode 300.

[0043] In this embodiment, each negative electrode 100, each separator layer 200, and each positive electrode 300 are alternately stacked along a first direction, which is also the thickness direction of the electrode core, such as along... Figure 2 As shown along the Y-axis, the edges of the negative electrode 100 and the separator layer 200 on the same side both extend beyond the edge of the positive electrode 300. Along the first direction, by pressing, the extended edges of each negative electrode 100 and each separator layer 200 can sequentially form a closing section 101 and an overlapping section 102. The closing section 101 and the overlapping section 102 are arranged sequentially along a second direction, which is perpendicular to the first direction and away from the positive electrode 300. Figure 2 As shown in the X-axis direction, this encapsulates the edge of the electrode core. It should be noted that when this electrode core is used in a solid-state battery, the separator 200 is the electrolyte, while when used in a liquid-state battery, the separator 200 is the membrane. Both are conventional technology products and are commercially available.

[0044] It is understandable that the application of the electrode core in this embodiment encapsulates the edges of each negative electrode sheet 100 and the edges of each separator layer 200 by joining and overlapping, which can reduce internal resistance, prevent the edges of the negative electrode sheet 100 from bending sharply, reduce the shedding and slippage of the coating, and thus ensure the performance of the battery.

[0045] Therefore, the electrode core provided in this embodiment includes multiple negative electrode sheets 100, multiple separator layers 200, and multiple positive electrode sheets 300. By alternately stacking each negative electrode sheet 100, each separator layer 200, and each positive electrode sheet 300 along a first direction, the edges of at least one negative electrode sheet 100 and the edges of the separator layer 200 on the same side extend beyond the edge of the positive electrode sheet 300. The extended portions of each negative electrode sheet 100 and each separator layer 200 approach each other and sequentially form a closing section 101 and an overlapping section 102 along a second direction. The second direction intersects with the first direction. That is, by closing and overlapping the extended portions of the edges of each negative electrode sheet 100 and each separator layer 200, internal resistance can be reduced, sharp bending of the edges of the negative electrode sheet 100 can be avoided, and the coating can be reduced from falling off or slipping, thereby ensuring the performance of the battery.

[0046] In some embodiments, the angle θ0 between the surface of the folding section 101 and the second direction is less than or equal to 80° and greater than 0° along the first direction. Preferably, the angle θ0 between the surface of the folding section 101 and the second direction is greater than or equal to 45°.

[0047] Specifically, as shown in Figure 2 the angle θ0 between the surface of the folding section 101 and the second direction is less than or equal to 80° and greater than 0°. That is, the angle θ0 between the plane where the folding section 101 is located and the plane where the overlapping part of the negative plate 100 is located is less than or equal to 80° and greater than 0°. As shown in Figure 2 for example, θ0 can be 45°, 53°, 57°, 64°, 65°, 70°, 72°, etc. By controlling the bending angle of the folding section 101 relative to the second direction within a reasonable range, sharp bending can be avoided. Of course, it can also be other angles, which can be determined according to actual needs.

[0048] In some embodiments, the length of the folding section 101 along the second direction is a first relative length L1 along the first direction, and the sum of the lengths of the folding section 101 and the overlapping section 102 of the outermost negative plate 100 along the second direction is a second relative length L2, and the ratio of the first relative length L1 to the second relative length L2 is greater than or equal to 0.4 and less than 1.

[0049] Specifically, as shown in Figure 2 the first relative length L1 is also the length of the projection of the folding section 101 on the plane where the overlapping part of the negative plate 100 is located along the second direction. The second relative length L2 is also the length of the projection of the folding section 101 and the overlapping section 102 on the plane where the overlapping part of the negative plate 100 is located along the second direction, and the ratio of the first relative length L1 to the second relative length L2 is greater than or equal to 0.4 and less than 1. For example, L1 / L2 can be equal to 0.411, 0.424, 0.518, 0.579, 0.772, 0.897, 0.934, etc. By controlling the proportion of the folding section 101 relative to the total length of the folding section 101 and the overlapping section 102 within a reasonable range, the folding section 101 can be smoothly transitioned, and sharp bending can be avoided. Of course, it can also be other ratios, which can be determined according to actual needs.

[0050] Further, in the present embodiment, the length of the excess part along the second direction is an initial length L0, and the ratio of the first relative length L1 to the initial length L0 is greater than or equal to 0.3 and less than 1.

[0051] Specifically, the initial length L0 is the sum of the lengths of the joined section 101 and the overlapping section 102 along the second direction before pressing, or the sum of the unfolded lengths of the joined section 101 and the overlapping section 102. L1 / L0 can be 0.337, 0.354, 0.409, 0.441, 0.679, 0.757, 0.882, etc. By controlling the proportion of the length of the joined section 101 relative to the length of the overlapping section 102 along the second direction within a reasonable range, sharp bending can be avoided. Of course, other length proportions are also possible, depending on actual needs.

[0052] Furthermore, in this embodiment, the negative electrode 100 and the separator layer 200 on both sides are arranged symmetrically along the first direction, that is, the first relative length L1 of the corresponding negative electrode 100 and separator layer 200 on both sides is equal.

[0053] That is, such as Figure 2 As shown, the projections of the closing segments 101 of the upper and lower negative electrode sheets 100 and the separator layer 200 onto the plane where the overlapping portions of the corresponding negative electrode sheets 100 are located, along the second direction, are equal in length. Correspondingly, the second relative lengths L2 of the negative electrode sheets 100 and the separator layer 200 on both sides can also be equal. That is, the projections of the closing segments 101 and overlapping segments 102 of the upper and lower negative electrode sheets 100 and the separator layer 200 onto the plane where the overlapping portions of the corresponding negative electrode sheets 100 are located, along the second direction, are all equal in length.

[0054] In some embodiments, along the first direction, the thickness of the overlapping section 102 at the junction with the closing section 101 is a first thickness H1, and the sum of the thicknesses of the overlapping portions of each negative electrode 100, each separator layer 200 and each positive electrode 300 is a second thickness H0, and the ratio of the first thickness H1 to the second thickness H0 is greater than or equal to 0.33 and less than 1.

[0055] Specifically, such as Figure 2 As shown, the sum of the thicknesses of the overlapping portions of each negative electrode 100, each separator layer 200, and each positive electrode 300 is also the sum of the thicknesses of each body segment 110, each separator layer 200, and each positive electrode 300. The body segment 110 is the main body of the negative electrode 100, and the joining segment 101 and overlapping segment 102 are the encapsulation portions of the negative electrode 100. The joining segment 101 is located on the periphery of the body segment 110, and the overlapping segment 102 is located away from the body segment 110 and on the periphery of the joining segment 101.

[0056] For example, H1 / H0 can be equal to 0.394, 0.389, 0.419, 0.464, etc. By controlling the proportion of each overlapping segment 102 relative to the total thickness of each negative electrode 100, each separator layer 200, and each positive electrode 300 within a reasonable range, the sum of the thicknesses of each overlapping segment 102 can be kept too small, avoiding sharp bending. Of course, other ratios are also possible, depending on actual needs.

[0057] In some embodiments, along the first direction, the angle θ between the surface of the overlapping section 102 and the second direction is less than or equal to 5° and greater than or equal to 0°.

[0058] That is, the angle θ between the plane of the overlapping section 102 and the plane of the overlapping part of the negative electrode 100 is less than or equal to 5° and greater than or equal to 0°. For example... Figure 2 As shown, the plane of the overlapping section 102 is made as parallel as possible to the plane of the overlapping part of the negative electrode 100 to ensure the overlapping effect. θ can be determined according to actual needs.

[0059] In some embodiments, the separator layer 200 includes a solid electrolyte layer. For example, at least one of oxides, sulfides, and halides can be used in solid-state batteries.

[0060] In some embodiments, along the second direction, the length of the separator layer 200 is equal to the length of the negative electrode 100.

[0061] In this way, the separator layer 200 can be coated on the surface of the negative electrode 100, which facilitates processing and molding.

[0062] In some embodiments, along the first direction, the outermost layer of the electrode core is a negative electrode sheet 100.

[0063] Specifically, such as Figure 1 As shown, the top and bottom layers of the core are both negative electrode sheets 100, which adopts the design concept of negative-encased positive to ensure the stability of the battery.

[0064] It should be noted that the electrode core provided in this embodiment includes a positive electrode sheet 300 comprising a current collector and a positive electrode material coated on at least one side of the current collector in the thickness direction, a solid electrolyte, a conductive agent, and a polymer binder. The positive electrode material includes at least one of olivine, layered oxides, spinel, sulfur, and sulfides. The olivine includes lithium iron phosphate (LiFePO4), the layered oxides include at least one of nickel cobalt manganese (NCM), nickel cobalt aluminum (NCA), or lithium cobalt oxide (LiCoO2), and the spinel includes lithium manganese oxide (LiMn2O4) and lithium titanate (Li4Ti5O4). 12 At least one of the following: sulfur (S8), and sulfides including at least one of iron disulfide (FeS2) and copper sulfide (CuS).

[0065] Solid electrolytes include at least one of oxides, sulfides, and halides, wherein the oxides include at least one of lithium lanthanum zirconium oxide (LLZO) and lithium titanium aluminum phosphate (LATP), and the sulfides include lithium thiophosphate (Li3PS4), lithium germanium phosphorus sulfide (LGPS), and Li 9.54 Si 1.74P 1.44 S 11.7 Cl 0.3 Li 6-x PS 5-x Cl 1+x Lithium phosphorus sulfur (Li7P3S) 11 At least one of Li4PS4I and Li7P2S8I, and the halides include at least one of Li3InCl6, Li2ZrO4, and Li3YCl6.

[0066] The conductive agent includes at least one of acetylene black, carbon nanotubes, carbon fibers, and carbon black, and the polymer binder includes at least one of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), styrene-butadiene rubber (SBR), nitrile rubber (NBR), polyacrylate, polyacrylic acid (PAA), alkyl cellulose, and polyethylene oxide (PEO).

[0067] The weight percentage of the above-mentioned positive electrode material can be (40~94) wt%, the weight percentage of the solid electrolyte can be (5~60) wt%, the weight percentage of the conductive agent can be (0~10) wt%, and the weight percentage of the polymer binder can be (0.1~10) wt%.

[0068] Furthermore, the separator layer 200 may include a solid electrolyte and a polymer binder, the selection of which may be the same as in the positive electrode 300. The negative electrode 100 includes a current collector and a negative electrode material coated on at least one side of the current collector in the thickness direction, a conductive additive, a binder, and a solid electrolyte. The negative electrode material may include at least one of a carbon material and a silicon material. The carbon material includes at least one of graphite and hard carbon, and the silicon material includes at least one of silicon (Si) and silicon alloys.

[0069] The following will provide a detailed description of the electrode core provided by the present invention and its applications through specific embodiments. Unless otherwise specified, the materials used in the following embodiments are conventional materials in the art and can be obtained commercially.

[0070] Example 1

[0071] This embodiment provides an electrode core and a battery cell, the preparation method of which is as follows:

[0072] The cathode material chosen is LiNi. 0.9 Co 0.05 Mn 0.05O2, solid electrolyte is Li6PS5Cl1, binder is HNBR, conductive agent is Sup P, and the positive electrode sheet 300 is prepared in a proportion of 80:20:1:1, and the solid electrolyte is Li6PS5Cl1 and the binder is HNBR in a proportion of 99:1 to prepare the separator 200, and the separator 200 is combined with the negative electrode material by rolling and transferring to prepare the negative electrode-electrolyte composite sheet.

[0073] The positive electrode sheet 300 has a die-cut size of 100mm*80mm and a thickness of 150um after compaction, the negative electrode-electrolyte composite sheet has a die-cut size of 103mm*83mm and a thickness of 90um after compaction, the negative electrode-electrolyte composite sheet exceeds the edge of the positive electrode sheet 300 by 1.5mm around, the number of stacking layers of the positive electrode sheet 300 is 12, and the number of stacking layers of the negative electrode-electrolyte composite sheet is 13.

[0074] After the negative electrode-electrolyte composite sheet and the positive electrode sheet 300 are alternately placed, isostatic pressing is performed under the conditions of a pressure of 500MPa, a temperature of 80℃ and a time of 60s, and a battery monomer is obtained after winding and packaging, the 0.1C first circle discharge capacity and the first circle coulombic efficiency of the battery are tested under a restraint pressure of 10MPa, and the cycle performance under 0.5C is tested.

[0075] Example 2

[0076] The negative electrode-electrolyte composite sheet has a die-cut size of 104mm*84mm, and the negative electrode-electrolyte composite sheet exceeds the edge of the positive electrode sheet 300 by 2.0mm around.

[0077] Example 3

[0078] The negative electrode-electrolyte composite sheet has a die-cut size of 102mm*82mm, and the negative electrode-electrolyte composite sheet exceeds the edge of the positive electrode sheet 300 by 1.0mm around.

[0079] Example 4

[0080] The number of stacking layers of the positive electrode sheet 300 is 16, and the number of stacking layers of the negative electrode-electrolyte composite sheet is 17.

[0081] Example 5

[0082] This embodiment provides an electrode core and a battery cell, which are basically the same as those in Embodiment 1, except that they are formed by isostatic pressing under conditions of 600MPa pressure, 80℃ temperature and 60s time.

[0083] Example 6

[0084] This embodiment provides an electrode core and a battery cell, which are basically the same as those in Embodiment 1, except that the thickness of the negative electrode-electrolyte composite sheet after compaction is 100 μm.

[0085] Example 7

[0086] This embodiment provides an electrode core and a battery cell, which are basically the same as those in Embodiment 1, except that the thickness of the negative electrode-electrolyte composite sheet after compaction is 120 μm.

[0087] Comparative Example 1

[0088] This embodiment provides an electrode core and a battery cell, which are basically the same as those in Embodiment 1, except that the thickness of the negative electrode-electrolyte composite sheet after compaction is 60 μm.

[0089] Comparative Example 2

[0090] This embodiment provides an electrode core and a battery cell, which are basically the same as those in Embodiment 1. The difference is that the die-cut size of the negative electrode-electrolyte composite sheet is 107mm*87mm, and the negative electrode-electrolyte composite sheet extends 3.5mm beyond the edge of the positive electrode sheet.

[0091] Comparative Example 3

[0092] This embodiment provides an electrode core and a battery cell, which are basically the same as those in Embodiment 1, except that they are formed by isostatic pressing under conditions of 600MPa pressure, 80℃ temperature and 600s time.

[0093] Comparative Example 4

[0094] This embodiment provides an electrode core and a battery cell, which are basically the same as those in Embodiment 1. The difference is that the thickness of the positive electrode sheet 300 after compaction is 180 μm, and the thickness of the negative electrode-electrolyte composite sheet after compaction is 70 μm.

[0095] The parameters of the electrode core provided in this application and the comparative electrode core are shown in Table 1 below, and the electrochemical performance test results of the battery cell made using the electrode core are shown in Table 2 below.

[0096] Table 1

[0097]

[0098] Table 2

[0099]

[0100] As can be seen from Tables 1 and 2, in Examples 1-7, H1 / H0 is greater than 0.33 and less than 1, θ0 is less than 80° and greater than 0, L1 / L0 is greater than 0.3 and less than 1, and L1 / L2 is greater than 0.4 and less than 1. Electrochemical performance test results show that the first-cycle discharge capacity is above 200mAh, the first-cycle coulombic efficiency is above 80%, the number of cycles is above 200, and self-discharge is relatively low.

[0101] In Comparative Examples 1-4, H1 / H0 of Comparative Examples 1 and 4 were less than 0.33, θ0 was greater than 80°, L1 / L0 was less than 0.3, and L1 / L2 was less than 0.4. Electrochemical performance tests showed that only the batteries in Comparative Examples 1 and 3 could be charged and discharged, while the batteries in Comparative Examples 2 and 4 caused short circuits. Furthermore, the first-cycle discharge capacity of Comparative Examples 1 and 3 did not exceed 200mAh, the first-cycle coulombic efficiency did not exceed 80%, the number of cycles was around 80, and the self-discharge was relatively high, exceeding 30.

[0102] Therefore, the electrode core provided in this application encapsulates the edges of each negative electrode sheet 100 by joining and overlapping, and limits the size of the joining section 101 and the overlapping section 102 within a reasonable range to avoid sharp bending of the edges of the negative electrode sheet 100, reduce the shedding and slippage of the coating, and thus ensure the performance of the battery.

[0103] Secondly, embodiments of this application also provide a battery cell, including a casing and an electrode core provided in any of the above embodiments, wherein the electrode core is disposed within the casing. That is, the electrode core is encapsulated into a battery cell by the casing.

[0104] The structure of the core has been described in detail in the above embodiments, and will not be repeated here.

[0105] The battery cell provided in this application embodiment, by configuring the electrode core, includes multiple negative electrode sheets 100, multiple separator layers 200, and multiple positive electrode sheets 300. By alternately stacking each negative electrode sheet 100, each separator layer 200, and each positive electrode sheet 300 along a first direction, the edges of at least one negative electrode sheet 100 and the edges of the separator layers 200 on the same side extend beyond the edge of the positive electrode sheet 300. The extended portions of each negative electrode sheet 100 and each separator layer 200 approach each other and sequentially form a closing section 101 and an overlapping section 102 along a second direction. The second direction intersects with the first direction. That is, by closing and overlapping the extended portions of the edges of each negative electrode sheet 100 and each separator layer 200, internal resistance can be reduced, sharp bending of the edges of the negative electrode sheet 100 can be avoided, and the shedding and slippage of the coating can be reduced, thereby ensuring the performance of the battery.

[0106] Thirdly, embodiments of this application also provide a battery device, including a housing and at least one battery cell provided in any of the above embodiments, wherein the battery cell is disposed within the housing.

[0107] Specifically, multiple of the aforementioned battery cells can be assembled into a battery pack by connecting them in series and parallel, and then combined with a cold plate, a sampling system, etc., to form a battery device.

[0108] The battery device provided in this application embodiment configures a battery cell, which includes an electrode core. The electrode core includes multiple negative electrode sheets 100, multiple separator layers 200, and multiple positive electrode sheets 300. By alternately stacking the negative electrode sheets 100, separator layers 200, and positive electrode sheets 300 along a first direction, the edges of at least one negative electrode sheet 100 and separator layer 200 on the same side extend beyond the edge of the positive electrode sheet 300. The extended portions of the negative electrode sheets 100 and separator layers 200 approach each other and sequentially form a closing section 101 and an overlapping section 102 along a second direction. The second direction intersects with the first direction. That is, by closing and overlapping the extended portions of the edges of the negative electrode sheets 100 and separator layers 200, internal resistance can be reduced, sharp bending of the edges of the negative electrode sheets 100 can be avoided, and the shedding and slippage of the coating can be reduced, thereby ensuring the performance of the battery.

[0109] Fourthly, embodiments of this application also provide an electrical device, including a device body, the device body being provided with a battery cell or battery device as described in any of the above embodiments. This electrical device can be a new energy vehicle, an aircraft, a computer, or an energy storage power station, etc.

[0110] The electrical device provided in this application embodiment, by configuring the above-mentioned battery cell or battery device having the above-mentioned battery cell, the battery cell includes an electrode core, the electrode core includes multiple negative electrode sheets 100, multiple separator layers 200 and multiple positive electrode sheets 300, by alternately stacking each negative electrode sheet 100, each separator layer 200 and each positive electrode sheet 300 along a first direction, such that the edges of at least one negative electrode sheet 100 and the edges of the separator layers 200 on the same side exceed the edges of the positive electrode sheet 300, the exceeding portions of each negative electrode sheet 100 and each separator layer 200 approach each other, and sequentially form a closing section 101 and an overlapping section 102 along a second direction, the second direction intersecting the first direction, that is, by closing and overlapping the exceeding portions of the edges of each negative electrode sheet 100 and each separator layer 200, the internal resistance can be reduced, the sharp bending of the edges of the negative electrode sheet 100 can be avoided, the dressing falling off and slipping can be reduced, thereby ensuring the performance of the battery.

[0111] Other embodiments of the application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. It is intended that the specification and examples be considered as exemplary only, with the true scope and spirit of the application being indicated by the following claims.

[0112] It is to be understood that the application is not limited to the precise construction herein described and shown in the accompanying drawings, and that various modifications and changes can be made by those skilled in the art without departing from the scope of the application. The scope of the application is limited only by the claims that follow.

Claims

1. An electrode core, characterized in that, It includes multiple negative electrode plates (100), multiple separator layers (200) and multiple positive electrode plates (300). Each of the negative electrode sheets (100), each of the separator layers (200) and each of the positive electrode sheets (300) are stacked alternately along a first direction, and along a second direction, the edges of at least one negative electrode sheet (100) and the edge of the separator layer (200) on the same side extend beyond the edge of the positive electrode sheet (300); The extended portions of each negative electrode sheet (100) and each separator layer (200) approach each other and sequentially form a closing section (101) and an overlapping section (102) along the second direction, which intersects with the first direction.

2. The electrode core according to claim 1, characterized in that, Along the first direction, the angle between the surface of the closing segment (101) and the second direction is less than or equal to 80° and greater than 0°.

3. The electrode core according to claim 2, characterized in that, The angle between the surface of the closing section (101) and the second direction is greater than or equal to 45°.

4. The electrode core according to claim 1, characterized in that, Along the first direction, the length of the closing segment (101) along the second direction is the first relative length, and the sum of the lengths of the closing segment (101) and the overlapping segment (102) along the second direction is the second relative length. The ratio of the first relative length to the second relative length is greater than or equal to 0.4 and less than 1.

5. The electrode core according to claim 4, characterized in that, Along the second direction, the length of the extended portion is the initial length, and the ratio of the first relative length to the initial length is greater than or equal to 0.3 and less than 1.

6. The electrode core according to claim 4, characterized in that, Along the first direction, the negative electrode (100) and the separator layer (200) on both sides are arranged symmetrically.

7. The electrode core according to claim 1, characterized in that, Along the first direction, the thickness of the overlapping section (102) at the junction with the closing section (101) is the first thickness, and the sum of the thicknesses of the overlapping portions of each negative electrode sheet (100), each separator layer (200) and each positive electrode sheet (300) is the second thickness. The ratio of the first thickness to the second thickness is greater than or equal to 0.33 and less than 1.

8. The electrode core according to claim 1, characterized in that, Along the first direction, the angle between the surface of the overlapping section (102) and the second direction is less than or equal to 5° and greater than or equal to 0°.

9. The electrode core according to claim 1, characterized in that, The separator layer (200) includes a solid electrolyte layer.

10. The electrode core according to claim 1, characterized in that, Along the second direction, the length of the separator layer (200) is equal to the length of the negative electrode sheet (100).

11. The electrode core according to any one of claims 1 to 10, characterized in that, Along the first direction, the outermost layer of the electrode core is the negative electrode sheet (100).

12. A single battery cell, characterized in that, It includes a housing and an electrode core as described in any one of claims 1 to 11, wherein the electrode core is disposed within the housing.

13. A battery device, characterized in that, It includes a housing and at least one battery cell as described in claim 12, the battery cell being disposed within the housing.

14. An electrical appliance, characterized in that, Includes a device body, on which a battery cell as described in claim 12 is disposed; Alternatively, the device body may be provided with the battery device as described in claim 13.

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