Battery cell, battery, and electric device

Abstract

A battery cell, a battery, and an electric device. The battery cell comprises an electrode assembly; the electrode assembly comprises a positive electrode sheet, a negative electrode sheet and a separator located between the positive electrode sheet and the negative electrode sheet; the negative electrode sheet comprises a negative electrode composite current collector and a negative electrode active layer located on at least one surface of the negative electrode composite current collector; and the negative electrode composite current collector comprises a polymer material supporting layer and a conductive layer located on the surface of the polymer material supporting layer.

Description

Battery cell, battery and electric device TECHNICAL FIELD

[0001] The present application relates to the field of batteries, in particular to a battery cell, a battery and an electric device. BACKGROUND

[0002] The statements herein are provided only to complement the background of the present application and do not necessarily constitute the prior art.

[0003] In recent years, batteries such as lithium ion batteries are widely used in energy storage power systems such as hydraulic, thermal, wind and solar power stations, and in many fields such as electric tools, electric bicycles, electric motorcycles, electric vehicles, military equipment, aerospace, etc. With the continuous expansion of the use range of batteries such as lithium ion batteries, higher requirements are also put forward for the performance of the batteries. In the use process of the battery, the expansion of the active layer in the negative electrode sheet will extrude the negative electrode current collector, increase the risk of damage to the negative electrode current collector, and thus affect the performance of the battery.

[0004] SUMMARY

[0005] The present application provides a battery cell. The battery cell comprises an electrode assembly; the electrode assembly comprises a positive electrode sheet, a negative electrode sheet and a separator film between the positive electrode sheet and the negative electrode sheet; the negative electrode sheet comprises a negative electrode composite current collector and a negative electrode active layer on at least one surface of the negative electrode composite current collector, and the negative electrode composite current collector comprises a polymer material support layer and a conductive layer on the surface of the polymer material support layer.

[0006] In the above-mentioned battery cell, by providing the negative electrode composite current collector comprising the polymer material support layer, the influence of the negative electrode active layer expansion on the negative electrode composite current collector can be reduced, and the risk of damage to the negative electrode composite current collector in the use process of the battery cell can be reduced.

[0007] In some embodiments, the fracture elongation of the negative electrode composite current collector is ≥30%. The negative electrode composite current collector has a higher fracture elongation, which can further reduce the risk of damage to the negative electrode composite current collector.

[0008] In some embodiments, the fracture elongation of the negative electrode composite current collector is 30%-150%. The fracture elongation of the negative electrode composite current collector in this range can take into account better fracture resistance and better processing performance, which is convenient for processing of the negative electrode composite current collector meeting the fracture elongation condition.

[0009] In some embodiments, the electrode assembly is configured as a flat structure, and the electrode assembly comprises a flat portion and corner portions arranged at both ends of the flat portion. By arranging the negative electrode composite current collector comprising a polymer material support layer, the negative electrode composite current collector at the corner portion of the battery cell can maintain a relatively stable structure during use of the battery cell, thereby reducing the risk of damage to the negative electrode composite current collector at the corner portion.

[0010] In some embodiments, the minimum value of the gap between the adjacent positive electrode sheet and the negative electrode sheet at the corner portion of the battery cell is 20-40 pm at 97% SOC. The minimum value of the gap between the adjacent positive electrode sheet and the negative electrode sheet at the corner portion of the battery cell at 97% SOC in this range can allow the electrolyte to better infiltrate the positive electrode sheet and the negative electrode sheet, and can also reduce the risk of short circuit due to contact between the positive electrode sheet and the negative electrode sheet.

[0011] In some embodiments, the minimum value of the gap between the adjacent positive electrode sheet and the negative electrode sheet at the corner portion of the battery cell is 30-80 pm at 3% SOC. The minimum value of the gap between the adjacent positive electrode sheet and the negative electrode sheet at the corner portion of the battery cell at 3% SOC in this range can allow the electrolyte to better infiltrate the positive electrode sheet and the negative electrode sheet, and can also reduce the risk of short circuit due to contact between the positive electrode sheet and the negative electrode sheet.

[0012] In some embodiments, the negative active material of the negative active layer comprises a silicon material. The negative active material comprising a silicon material can improve the energy density of the battery.

[0013] In some embodiments, the mass percentage of the silicon material in the negative active material is less than or equal to 5%, and the fracture elongation of the negative electrode composite current collector is 60-100%.

[0014] In some embodiments, the mass percentage of the silicon material in the negative active material is greater than 5% and less than or equal to 15%, and the fracture elongation of the negative electrode composite current collector is 80-120%.

[0015] In some embodiments, the mass percentage of the silicon material in the negative active material is greater than 15% and less than or equal to 25%, and the fracture elongation of the negative electrode composite current collector is 90-130%.

[0016] In some embodiments, the mass percentage of the silicon material in the negative active material is greater than 25% and less than or equal to 50%, and the fracture elongation of the negative electrode composite current collector is 90-150%.

[0017] In some embodiments, the silicon material includes at least one of elemental silicon, silicon oxide, silicon-carbon composite, silicon-graphene composite, and silicon-carbon nanotube composite.

[0018] In some embodiments, the polymer material support layer includes a polymer material, and the polymer material has a number average molecular weight of 6000-9500. The polymer material with the number average molecular weight in the range can make the polymer material support layer have better extension performance and better processing performance.

[0019] In some embodiments, the polymer material includes at least one of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, and polyethylene.

[0020] In some embodiments, the battery cell includes a housing for accommodating the electrode assembly.

[0021] In some embodiments, the housing has a square shape, and the housing includes a shell and at least one end cover; wherein the shell has an opening at only one end, and the end cover covers the opening; or the shell has an opening at each end, and two end covers respectively cover the two openings.

[0022] In some embodiments, the housing has a soft package structure, and a material of the housing includes an aluminum plastic film.

[0023] In some embodiments, the housing has a cylindrical shape, and the housing includes a shell and at least one end cover, the end cover covers an opening of the shell, and an outer diameter of the cylindrical shape is greater than or equal to 30 mm.

[0024] A battery includes the battery cell.

[0025] A power consumption device includes at least one of the battery cell and the battery. BRIEF DESCRIPTION OF DRAWINGS

[0026] For better describing and illustrating the embodiments or examples provided in the present application, one or more drawings can be referred to. Additional details or examples used for describing the drawings should not be considered as limiting the scope of any one of the disclosed applications, the presently described embodiments or examples, and the best mode presently understood of these applications. Moreover, the same reference numbers are used throughout the drawings to represent the same components. In the drawings:

[0027] FIG. 1 is a schematic diagram of a battery according to an embodiment of the present application.

[0028] FIG. 2 is an exploded view of the battery according to an embodiment of the present application shown in FIG. 1.

[0029] FIG. 3 is a schematic view of a power consuming device using the battery as a power source according to an embodiment of the present application.

[0030] BRIEF DESCRIPTION OF DRAWINGS 1: battery cell; 11: case; 12: electrode assembly; 13: cover plate; 2: power consuming device.

[0031] For a better understanding of those embodiments and / or examples of the application herein disclosed, reference can be made to one or more of the accompanying drawings. The additional details or examples used to describe the drawings should not be considered as limiting the scope of any of the disclosed applications, presently described embodiments and / or examples, and the best mode presently contemplated of those applications. DETAILED DESCRIPTION

[0032] For the purpose of facilitating an understanding of the present application, a more complete appreciation of which can be gained by reference to the following detailed description and the accompanying drawings. The detailed description and drawings are only exemplary of the present application. The present application can be implemented in numerous ways, including but not limited to those described herein and those related to the drawings. Rather, these embodiments are illustrative of the disclosure of the present application and are not intended to limit the scope of the applications, presently described embodiments and / or examples, and the best mode presently contemplated of those applications.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0034] "ranges" disclosed herein can be defined, for example, by the lower and upper values. Any lower limit can independently be combined with any upper limit to define a range of any value. For example, if a range of 60-120 and 80-110 is listed as exemplary, it is understood that a range of 60-110 and 80-120 are also contemplated. Furthermore, if a minimum range value of 1 and 2 is listed, and if a maximum range value of 3, 4, and 5 is also listed, then the following ranges are all contemplated: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, the use of "a" and "an" to describe a single item can be taken as equivalent to the use of "one" or "at least one," unless otherwise limited by context. In this application, the use of "or" as a conjunction can be taken as

[0035] In this application, the use of "a" and "an" to describe a single item can be taken as equivalent to the use of "one" or "at least one," unless otherwise limited by context. In this application, the use of "or" as a conjunction can be taken as

[0036] All embodiments and optional embodiments of the present application can be combined with each other to form new technical solutions, if not specifically stated.

[0037] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment or implementation of the application. The appearances of the phrase that the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive of other embodiments. It is explicitly understood that the embodiments described herein are combinable with each other. Reference herein to "an implementation" has a similar understanding.

[0038] Those skilled in the art can understand that the order of writing each step in the method of each embodiment or example does not mean a strict execution order and does not constitute any limitation on the implementation process. The detailed execution order of each step should be determined by its function and possible internal logic. If not specifically stated, all steps of the present application can be performed in sequence or randomly. For example, the method includes steps (a) and (b), which means that the method can include steps (a) and (b) performed in sequence, or steps (b) and (a) performed in sequence. For example, the method also includes step (c), which means that step (c) can be added to the method in any order, for example, the method can include steps (a), (b) and (c), or steps (a), (c) and (b), or steps (c), (a) and (b), etc.

[0039] In the present application, the open technical features or technical solutions described by the words "containing", "including", "comprising" and the like do not exclude additional members other than the listed members, and can be regarded as providing both a closed feature or solution composed of the listed members and an open feature or solution including additional members in addition to the listed members. For example, A includes a1, a2 and a3, and unless otherwise specified, it can also include other members or can not include additional members, and can be regarded as providing both the feature or solution that "A is composed of a1, a2 and a3" and the feature or solution that "A includes a1, a2 and a3, and also includes other members".

[0040] In the present application, A (such as B) means that B is a non-limiting example of A, and A can be understood as not limited to B, unless otherwise specified.

[0041] In the present application, "optionally", "optional" and "optional" mean that it can or can not be present, that is, it is selected from either of the two parallel solutions "has" or "has not". If there are multiple "options" in a technical solution, unless otherwise specified, and there is no contradiction or mutual restriction, each "option" is independent.

[0042] An embodiment of the present application provides a battery monomer. The battery monomer comprises an electrode assembly; the electrode assembly comprises a positive electrode sheet, a negative electrode sheet and a separator film between the positive electrode sheet and the negative electrode sheet; the negative electrode sheet comprises a negative electrode composite current collector and a negative electrode active layer on at least one surface of the negative electrode composite current collector, and the negative electrode composite current collector comprises a polymer material support layer and a conductive layer on the surface of the polymer material support layer. In the battery monomer of the present embodiment, by arranging the negative electrode composite current collector comprising the polymer material support layer, the influence of the negative electrode active layer expansion on the negative electrode composite current collector can be reduced, and the risk of damage to the negative electrode composite current collector during use of the battery monomer can be reduced.

[0043] In some embodiments, the fracture elongation of the negative electrode composite current collector is ≥ 30%. The negative electrode composite current collector has a higher fracture elongation, which can further reduce the risk of damage to the negative electrode composite current collector.

[0044] The fracture elongation of the negative electrode composite current collector in the present application can be tested by the following method: disassembling a battery cell at 97% SOC to obtain a negative electrode sheet, removing the active layer on the surface of the negative electrode sheet to obtain a negative electrode composite current collector. The negative electrode composite current collector is cut to obtain a current collector sample with a length of 150 mm and a width of 25 mm. The sample is fixed on a tensile testing machine, and the clamps at both ends of the tensile testing machine clamp the sample in the length direction, and the distance between the clamps is L0, which is usually 50 mm. The tensile testing machine is controlled at a speed of 5 m / min, and stretched to the fracture of the sample, at which time the distance between the clamps is L1. The fracture elongation of the sample = (L1-L0) / L0 x 100%. It can be understood that SOC represents the state of charge of the battery cell.

[0045] In some embodiments, the fracture elongation of the negative electrode composite current collector is 30% to 150%. The fracture elongation of the negative electrode composite current collector in this range can take into account better fracture resistance and better processing performance, which is convenient for processing of the negative electrode composite current collector that meets the fracture elongation condition. Alternatively, the fracture elongation of the negative electrode composite current collector can be 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100%, 110%, 120%, 130%, 140%, 150%, and any value within the range formed by any two of the above values. Further alternatively, the fracture elongation of the negative electrode composite current collector is 60% to 100%.

[0046] In some embodiments, the electrode assembly is configured in a flat structure, and the electrode assembly includes a flat portion and a corner portion provided at both ends of the flat portion. At this time, the corresponding battery cell is configured as a wound battery cell. In this battery cell, compared with the flat portion, the expansion of the active layer has a more obvious effect on the corner portion. Through the provision of the negative electrode composite current collector including the high molecular material support layer, the negative electrode composite current collector of the corner portion of the battery cell can maintain a relatively stable structure during use of the battery cell, reducing the risk of damage to the negative electrode composite current collector at the corner.

[0047] In some embodiments, the minimum value of the gap (i.e., the Gap value) between the adjacent positive electrode tab and the negative electrode tab at the corner portion of the electrode assembly of the battery cell at 97% SOC is 20 μm to 40 μm. The minimum value of the gap between the adjacent positive electrode tab and the negative electrode tab at the corner portion of the electrode assembly of the battery cell at 97% SOC in this range can allow the electrolyte to better infiltrate the positive electrode tab and the negative electrode tab, and can also reduce the risk of short circuit due to contact between the positive electrode tab and the negative electrode tab. Alternatively, the minimum value of the gap between the adjacent positive electrode tab and the negative electrode tab at the corner portion of the battery cell at 97% SOC can be 20 μm, 22 μm, 25 μm, 28 μm, 30 μm, 32 μm, 35 μm, 38 μm, 40 μm, and any value in the range defined by any two of the above values.

[0048] In some embodiments, the minimum value of the gap (i.e., the Gap value) between the adjacent positive electrode tab and the negative electrode tab at the corner portion of the electrode assembly of the battery cell at 3% SOC is 30 μm to 80 μm. The minimum value of the gap between the adjacent positive electrode tab and the negative electrode tab at the corner portion of the electrode assembly of the battery cell at 3% SOC in this range can allow the electrolyte to better infiltrate the positive electrode tab and the negative electrode tab, and can also reduce the risk of short circuit due to contact between the positive electrode tab and the negative electrode tab. Alternatively, the minimum value of the gap between the adjacent positive electrode tab and the negative electrode tab at the corner portion of the battery cell at 3% SOC can be 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, and any value in the range defined by any two of the above values.

[0049] In the present application, the Gap value can be tested by the following test method: measured using an X-ray CT scanner, the direction of the X-ray irradiation is 45° to the winding axis of the battery cell and two-dimensional imaging, the distance value between the adjacent five layers of negative electrode tabs is measured using the device scale, then the electrode assembly is disassembled and the thickness values of the positive electrode tab, the separator and the negative electrode tab are measured using a micrometer, and the Gap value is calculated by the formula: Gap value = [distance value between the five layers of negative electrode tabs - (positive electrode tab thickness + negative electrode tab thickness) x 4 - separator x 8)] / 8.

[0050] In some embodiments, the negative active material of the negative active layer comprises a silicon material. The negative active material comprising the silicon material can improve the energy density of the battery. Meanwhile, in the negative composite current collector, the polymer material support layer can provide buffering for the volume expansion of the silicon material. During the charging process of the battery cell, the silicon material undergoes volume expansion, and the buffering effect of the polymer material support layer can better release the expansion stress, reduce the difficulty of electrolyte entering the negative electrode sheet, improve the wetting effect of the electrolyte on the negative active material, reduce the risk of lithium precipitation on the surface of the negative electrode sheet, and thus the battery can have both high energy density and good cycle performance. Further, during the charging process of the battery cell, after the expansion stress of the silicon material is well released, the expansion of the silicon material on the separation film can be better alleviated, which can reduce the risk of the separation film being closed, and thus the electrolyte can pass through the separation film smoothly, so that the battery can maintain good cycle performance.

[0051] Optionally, the silicon material comprises at least one of elemental silicon, silicon oxide compound, silicon-carbon composite, silicon-graphene composite material, and silicon-carbon nanotube composite material. Further optionally, the negative active material can further comprise graphite. Further optionally, the graphite comprises at least one of artificial graphite and natural graphite.

[0052] In some embodiments, the 97% SOC thickness expansion rate of the negative electrode sheet is 2% to 10%. For example, the 97% SOC thickness expansion rate of the negative electrode sheet can be 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, and any value within the range formed by any two of the above values.

[0053] The 97% SOC thickness expansion rate of the negative electrode sheet in the present application can be tested by the following method: taking battery cells at 97% SOC and 3% SOC respectively, and disassembling to obtain negative electrode sheets. The thickness of the negative electrode sheet at 3% SOC is T0, and the thickness of the negative electrode sheet at 97% SOC is T1. The 97% SOC thickness expansion rate of the negative electrode sheet is (T1-T0) / T0x100%.

[0054] In some embodiments, the percentage of silicon material in the mass of the negative active material is less than or equal to 5%, and the fracture elongation of the negative composite current collector is 60% to 100%. The percentage of silicon material in the mass of the negative active material and the fracture elongation of the negative composite current collector are set in correspondence, which can better match the silicon material and the negative composite current collector, and alleviate the impact of the expansion of the silicon material on the battery. Optionally, the percentage of silicon material in the mass of the negative active material can be 0.1%, 0.3%, 0.5%, 0.8%, 1%, 1.2%, 1.5%, 1.8%, 2%, 2.2%, 2.5%, 2.8%, 3%, 3.2%, 3.5%, 3.8%, 4%, 4.2%, 4.5%, 5%, and any value within a range defined by any two of the above values. Optionally, the fracture elongation of the negative composite current collector can be 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100%, and any value within a range defined by any two of the above values.

[0055] In some embodiments, the percentage of silicon material in the mass of the negative active material is greater than 5% and less than or equal to 15%, and the fracture elongation of the negative composite current collector is 80% to 120%. The percentage of silicon material in the mass of the negative active material and the fracture elongation of the negative composite current collector are set in correspondence, which can better match the silicon material and the negative composite current collector, and alleviate the impact of the expansion of the silicon material on the battery. Optionally, the percentage of silicon material in the mass of the negative active material can be 5.1%, 5.3%, 5.5%, 5.8%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, and any value within a range defined by any two of the above values. Optionally, the fracture elongation of the negative composite current collector can be 80%, 85%, 90%, 95%, 100%, 105%, 100%, 105%, 110%, 115%, 120%, and any value within a range defined by any two of the above values.

[0056] In some embodiments, the percentage of silicon material in the mass of the negative active material is greater than 15% and less than or equal to 25%, and the breaking elongation of the negative composite current collector is 90% to 130%. The percentage of silicon material in the mass of the negative active material and the breaking elongation of the negative composite current collector are correspondingly set, which can better match the silicon material and the negative composite current collector, and alleviate the impact of the expansion of the silicon material on the battery. Optionally, the percentage of silicon material in the mass of the negative active material can be 15.1%, 15.3%, 15.5%, 15.8%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, and any value within a range constituted by any two of the above values. Optionally, the breaking elongation of the negative composite current collector can be 90%, 95%, 100%, 105%, 110%, 115%, 120%, 125%, 130%, and any value within a range constituted by any two of the above values.

[0057] In some embodiments, the percentage of silicon material in the mass of the negative active material is greater than 25% and less than or equal to 50%, and the breaking elongation of the negative composite current collector is 90% to 150%. The percentage of silicon material in the mass of the negative active material and the breaking elongation of the negative composite current collector are correspondingly set, which can better match the silicon material and the negative composite current collector, alleviate the impact of the expansion of the silicon material on the battery, and maintain good cycle performance of the battery. Optionally, the percentage of silicon material in the mass of the negative active material can be 25.1%, 25.3%, 25.5%, 25.8%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, and any value within a range constituted by any two of the above values. Optionally, the breaking elongation of the negative composite current collector can be 90%, 95%, 100%, 105%, 110%, 115%, 120%, 125%, 130%, 135%, 140%, 150%, and any value within a range constituted by any two of the above values.

[0058] In some embodiments, the material of the conductive layer includes at least one of copper and copper alloy.

[0059] In some embodiments, the high polymer material support layer comprises a high polymer material, and the number average molecular weight of the high polymer material is 6500-9500. The high polymer material with the number average molecular weight in this range can make the high polymer material support layer have better elongation performance and better processing performance. It can be understood that the better elongation performance means that the high polymer material support layer has a more appropriate breaking elongation. The better processing performance means that the high polymer material support layer can be more conveniently obtained by high polymer material flow casting film. Optionally, the number average molecular weight of the high polymer material can be 6000-6500, 6500-7000, 7000-7500, 7500-8000, 8000-8500, 8500-9000, 9000-9500, etc. Further optionally, the number average molecular weight of the high polymer material can be about 6000, about 7000, about 8000, about 9000, etc. Further optionally, the high polymer material comprises at least one of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), and polyethylene (PE).

[0060] In some embodiments, the breaking elongation of the high polymer material support layer is ≥100%. The high polymer material support layer with the breaking elongation in this range has better elongation performance, which on one hand can make the negative composite current collector maintain a relatively stable structure during use of the battery monomer, reducing the risk of damage to the negative composite current collector; on the other hand, during the cycle process of the battery monomer, the high polymer material support layer can buffer the expansion of the pole piece through its own compression, so that the adjacent positive pole piece and negative pole piece maintain a more appropriate distance, thereby enabling the electrolyte to better infiltrate the pole piece, while also reducing the risk of short circuit due to contact between the positive pole piece and the negative pole piece. Optionally, the breaking elongation of the high polymer material support layer is 70%-140%. Optionally, the breaking elongation of the high polymer material support layer can be 70%, 75%, 80%, 85%, 90%, 95%, 100%, 105%, 110%, 115%, 120%, 125%, 130%, 135%, 140%, and any value in the range constituted by any two of the above values.

[0061] The breaking elongation of the polymer material support layer in the present application can be tested by the following method: the polymer material corresponding to the polymer material support layer is obtained by flow casting to obtain a film with a thickness of 4.5 μm. The current collector is cut to obtain a sample with a length of 150 mm and a width of 25 mm. The sample is fixed on a tensile testing machine, and the clamps at both ends of the tensile testing machine clamp the sample in the length direction, and the distance between the clamps is L0, which is usually 50 mm. The tensile testing machine is controlled at a speed of 5 m / min, and stretched to the breaking of the sample, at which time the distance between the clamps is L1. The breaking elongation of the sample = (L1-L0) / L0 x 100%.

[0062] In some embodiments, the battery cell includes a housing for accommodating an electrode assembly.

[0063] In some embodiments, the housing is square in shape, and the housing includes a shell and at least one end cover; wherein the shell has an opening at only one end, and the end cover covers the opening; or the shell has an opening at both ends, and two end covers cover the two openings respectively.

[0064] In some embodiments, the housing is a soft package structure, and the material of the housing includes an aluminum plastic film.

[0065] In some embodiments, the housing is cylindrical in shape, and the housing includes a shell and at least one end cover, and the end cover covers an opening of the shell, and the outer diameter of the cylinder is greater than or equal to 30 mm.

[0066] The present application also provides a battery. The battery includes the above-mentioned battery cell.

[0067] The present application also provides a battery. The battery includes the above-mentioned battery cell.

[0068] The battery cell, the battery and the electric device of the present application will be described below with reference to the accompanying drawings.

[0069] Generally, the battery cell includes a positive electrode sheet, a negative electrode sheet, an electrolyte and a separator. During the charging and discharging process of the battery, active ions are embedded and extracted between the positive electrode sheet and the negative electrode sheet. The electrolyte plays a role in conducting ions between the positive electrode sheet and the negative electrode sheet. The separator is arranged between the positive electrode sheet and the negative electrode sheet, mainly to prevent the short circuit of the positive and negative electrodes, and at the same time to allow the ions to pass through.

[0070] Positive electrode sheet

[0071] The positive electrode sheet includes a positive current collector and a positive active layer arranged on at least one surface of the positive current collector, and the positive active layer includes a positive active material.

[0072] As a non-limiting example, the positive electrode current collector has two surfaces opposite in the thickness direction thereof, and the positive electrode active layer is provided on either one or both of the two surfaces of the positive electrode current collector.

[0073] In some embodiments, the positive electrode current collector can employ a metal foil or a composite current collector. For example, as the metal foil, an aluminum foil can be employed. The composite current collector can include a polymer material support layer and a conductive layer formed on at least one surface of the polymer material support layer. The composite current collector can be obtained by forming a conductive material on a polymer material substrate. In the positive electrode current collector, the conductive material includes a metal material. Non-limiting examples of the metal material can include one or more of aluminum, an aluminum alloy, nickel, a nickel alloy, titanium, a titanium alloy, silver, a silver alloy, and the like. Non-limiting examples of the polymer material substrate in the positive electrode current collector can include one or more of a polypropylene (PP) substrate, a polyethylene terephthalate (PET) substrate, a polybutylene terephthalate (PBT) substrate, a polystyrene (PS) substrate, a polyethylene (PE) substrate, and the like.

[0074] In some embodiments, the positive electrode active material can employ a positive electrode active material for a battery known in the art. As a non-limiting example, the positive electrode active material can include one or more of a lithium-containing phosphate of an olivine structure, a lithium transition metal oxide, and a modified compound of each thereof. However, the present application is not limited to these materials, and other conventional materials that can be used as a positive electrode active material for a battery can also be used. These positive electrode active materials can be used alone only one or in combination of two or more. Among them, examples of the lithium transition metal oxide can include, but are not limited to, one or more of a lithium cobalt oxide (e.g., LiCoO2), a lithium nickel oxide, a lithium manganese oxide, a lithium nickel cobalt oxide, a lithium manganese cobalt oxide, a lithium nickel manganese oxide, a lithium nickel cobalt manganese oxide, a lithium nickel cobalt aluminum oxide, and a modified compound thereof. Non-limiting examples of the lithium-containing phosphate of an olivine structure can include, but are not limited to, one or more of lithium iron phosphate, a composite of lithium iron phosphate and carbon, lithium manganese phosphate, a composite of lithium manganese phosphate and carbon, lithium manganese iron phosphate, a composite of lithium manganese iron phosphate and carbon. Non-limiting examples of the lithium cobalt oxide can include LiCoO2; non-limiting examples of the lithium nickel oxide can include LiNiO2; non-limiting examples of the lithium manganese oxide can include LiMnO2, LiMn2O4, and the like; non-limiting examples of the lithium nickel cobalt manganese oxide can include LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2(also referred to simply as NCM 333 ), LiNi 0.5 Co 0.2 Mn 0.3 O2(also referred to simply as NCM 523 ), LiNi 0.5Co 0.25 Mn 0.25 O2(also can be referred to as NCM 211 ), LiNi 0.6 Co 0.2 Mn 0.2 O2(also can be referred to as NCM 622 ), LiNi 0.8 Co 0.1 Mn 0.1 O2(also can be referred to as NCM 811 ), etc. Non-limiting examples of lithium nickel cobalt aluminum oxides can include LiNi 0.8 Co 0.15 Al 0.05 O2.

[0075] In some embodiments, the positive active layer can also optionally include a binder. As non-limiting examples, the binder can include one or more of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), a vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, a vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, a tetrafluoroethylene-hexafluoropropylene copolymer, and a fluorine-containing acrylate resin.

[0076] In some embodiments, the positive active layer can also optionally include a conductive agent. As non-limiting examples, the conductive agent can include one or more of super P carbon, acetylene black, carbon black, ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0077] In some embodiments, the positive electrode sheet can be prepared by dispersing the above-mentioned components for preparing the positive electrode sheet, such as the positive active material, the conductive agent, the binder, and any other components, in a solvent to form a positive electrode slurry; coating the positive electrode slurry on at least one side surface of the positive current collector, and after processes such as drying, cold pressing, etc., the positive electrode sheet can be obtained. The type of the solvent can be selected from, but is not limited to, any of the aforementioned embodiments, such as N-methyl pyrrolidone (NMP). The surface of the positive current collector to which the positive electrode slurry is coated can be on a single surface of the positive current collector, or on both surfaces of the positive current collector. The surface of the positive current collector to which the positive electrode slurry is coated can be on a single surface of the positive current collector, or on both surfaces of the positive current collector. The solid content of the positive electrode slurry can be 40wt% to 80wt%. The viscosity of the positive electrode slurry at room temperature can be adjusted to 5000mPa·s to 25000mPa·s. When coating the positive electrode slurry, the coating unit area density, in terms of dry weight (excluding the solvent), can be 15mg / cm 2 ~ 35mg / cm 2 . The compaction density of the positive electrode sheet can be 3.0g / cm 3 ~ 3.6g / cm 3Optionally 3.3 g / cm 3 ~3.5 g / cm 3 .

[0078] Negative electrode sheet

[0079] The negative electrode sheet includes a negative electrode current collector and a negative electrode active layer disposed on at least one surface of the negative electrode current collector, the negative electrode active layer including a negative electrode active material.

[0080] As a non-limiting example, the negative electrode current collector has two surfaces opposite in the thickness direction thereof, and the negative electrode active layer is disposed on either one or both of the two opposite surfaces of the negative electrode current collector.

[0081] In some embodiments, the negative electrode current collector can employ a metal foil or a composite current collector. For example, as the metal foil, a copper foil can be employed. The composite current collector can include a polymer material support layer and a conductive layer formed on at least one surface of the polymer material support layer. The composite current collector can be obtained by forming a conductive material on a polymer material substrate. In the negative electrode current collector, the conductive material includes a metal material. Non-limiting examples of the metal material can include one or more of copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, silver alloy, and the like. Non-limiting examples of the polymer material substrate in the negative electrode current collector can include one or more of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), and the like.

[0082] In some embodiments, the negative electrode active material can employ a negative electrode active material for a battery known in the art. As a non-limiting example, the negative electrode active material can include one or more of artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based material, tin-based material, lithium titanate, and the like. The silicon-based material can include one or more of elemental silicon, silicon oxide compound, silicon-carbon composite, silicon-nitrogen composite, and silicon alloy. The tin-based material can include one or more of elemental tin, tin oxide compound, and tin alloy. However, the present application is not limited to these materials, and other conventional materials that can be used as a negative electrode active material for a battery can also be used. The negative electrode active material can be used alone or in combination of two or more.

[0083] In some embodiments, the negative electrode active layer can further optionally include a binder. The binder can include one or more of styrene butadiene rubber (SBR), polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), polymethacrylic acid (PMAA), and carboxymethyl chitosan (CMCS).

[0084] In some embodiments, the negative active layer can optionally further include a conductive agent. The conductive agent can include one or more of super-P, acetylene black, carbon black, ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0085] In some embodiments, the negative active layer can optionally further include other additives, such as a thickening agent (e.g., sodium carboxymethyl cellulose (CMC-Na)), etc.

[0086] In some embodiments, the negative electrode sheet can be prepared by dispersing the above-mentioned components for preparing the negative electrode sheet, such as the negative active material, the conductive agent, the binder, and any other components, in a solvent (a non-limiting example of the solvent is deionized water) to form a negative electrode slurry; coating the negative electrode slurry on at least one side surface of the negative electrode current collector, and after processes such as drying, cold pressing, etc., the negative electrode sheet can be obtained. The surface of the negative electrode current collector to which the negative electrode slurry is coated can be either one surface of the negative electrode current collector or both surfaces of the negative electrode current collector. The solid content of the negative electrode slurry can be 40 wt% to 60 wt%. The viscosity of the negative electrode slurry at room temperature can be adjusted to 2000 mPa-s to 10000 mPa-s. When coating the negative electrode slurry, the coating unit area density (dry weight (excluding the solvent)) can be 75 g / m 2 ~ 220 g / m 2 . The compaction density of the negative electrode sheet can be 1.0 g / cm 3 ~ 1.8 g / cm 3 .

[0087] Electrolyte

[0088] The electrolyte has a function of conducting ions between the positive electrode sheet and the negative electrode sheet. The type of the electrolyte is not particularly limited in the present application, and can be selected as needed. For example, the electrolyte can be liquid, gel, or all-solid.

[0089] In some embodiments, the electrolyte employs an electrolyte solution. The electrolyte solution includes an electrolyte salt and a solvent.

[0090] In some embodiments, the electrolyte salt can include one or more of lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium perchlorate (LiClO4), lithium hexafluoroarsenate (LiAsF6), lithium bisfluorosulfonylimide (LiFSI), lithium bis-trifluoromethanesulfonylimide (LiTFSI), lithium trifluoromethanesulfonate (LiTFS), lithium difluorophosphate (LiPO2F2), lithium difluoro-oxalato-borate (LiDFOB), lithium bis-oxalato-borate (LiBOB), lithium difluoro-bis-oxalato-phosphate (LiDFOP), and lithium tetrafluoro-oxalato-phosphate (LiTFOP).

[0091] In some embodiments, the solvent can include one or more of ethylene carbonate (EC), ), propylene carbonate (PC, ), methyl ethyl carbonate (EMC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), methyl propyl carbonate (MPC), ethyl propyl carbonate (EPC), butylene carbonate fluorinated ethylene carbonate (FEC), methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, methyl ethyl sulfone, and diethyl sulfone.

[0092] In some embodiments, the electrolyte solution can further optionally include an additive. For example, the additive can include a negative electrode film-forming additive, a positive electrode film-forming additive, and can further include an additive capable of improving certain properties of the battery, such as an additive for improving overcharge performance of the battery, an additive for improving high-temperature or low-temperature performance of the battery, etc.

[0093] In some embodiments, the additive in the electrolyte solution can include, but is not limited to, one or more of fluorinated ethylene carbonate (FEC), difluoroethylene carbonate (DFEC), trifluoromethyl ethylene carbonate (TFPC), etc.

[0094] Separator film

[0095] In some embodiments, the battery cell further includes a separator film. The type of the separator film is not particularly limited in the present application, and any publicly known porous structure separator film having good chemical stability and mechanical stability can be used.

[0096] In some embodiments, the material of the separator film can include one or more of glass fiber, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator film can be a single layer film or a multi-layer composite film, and is not particularly limited. When the separator film is a multi-layer composite film, the materials of the respective layers can be the same or different, and are not particularly limited.

[0097] In some embodiments, the thickness of the separator film is 6 μm to 40 μm, and can be optionally 12 μm to 20 μm.

[0098] In some embodiments, the positive electrode sheet, the negative electrode sheet, and the separator film can be used to make an electrode assembly through a winding process or a stacking process.

[0099] In some embodiments, the battery cell can include an outer package. The outer package can be used to package the electrode assembly and the electrolyte solution described above.

[0100] In some embodiments, the outer packaging of the battery cell can be a hard shell, such as a hard plastic shell, an aluminum shell, a steel shell, etc. The outer packaging of the battery cell can also be a soft pack, such as a pouch soft pack. The material of the soft pack can be plastic, and further, non-limiting examples of the plastic can include one or more of polypropylene, polybutylene terephthalate, and polybutylene succinate, etc.

[0101] The battery includes at least one battery cell. The battery can include 1 or more battery cells.

[0102] In this application, unless otherwise specified, a "battery cell" refers to a basic unit capable of realizing mutual conversion between chemical energy and electrical energy, and further, generally includes at least a positive electrode sheet, a negative electrode sheet, and an electrolyte. During the charging and discharging process of the battery, active ions are embedded and extracted between the positive electrode sheet and the negative electrode sheet. The electrolyte plays a role in conducting active ions between the positive electrode sheet and the negative electrode sheet.

[0103] The shape of the battery cell is not particularly limited in this application, and it can be cylindrical, square, or any other shape. For example, FIG. 1 is a battery cell 1 of a square structure as an example.

[0104] In some embodiments, referring to FIG. 2, the outer packaging can include a shell 11 and a cover plate 13. Among them, the shell 11 can include a bottom plate and a side plate connected to the bottom plate, and the bottom plate and the side plate enclose a receiving cavity. The shell 11 has an opening communicating with the receiving cavity, and the cover plate 13 can be provided on the opening to close the receiving cavity. The positive electrode sheet, the negative electrode sheet, and the separator can form an electrode assembly 12 through a winding process or a stacking process. The electrode assembly 12 is packaged in the receiving cavity. The electrolyte is impregnated in the electrode assembly 12. The number of electrode assemblies 12 contained in the battery cell 1 can be one or more, and a person skilled in the art can select according to the actual needs.

[0105] The battery can be a battery module or a battery pack.

[0106] The battery module includes at least one battery cell. The number of battery cells contained in the battery module can be one or more, and a person skilled in the art can select a suitable number according to the application and capacity of the battery module.

[0107] In the battery module, the plurality of battery cells can be arranged in sequence along the length direction of the battery module. Of course, it can also be arranged in any other way. Further, the plurality of battery cells can be fixed by fasteners.

[0108] Optionally, the battery module can also include a housing having a receiving space, and the plurality of battery cells are received in the receiving space.

[0109] In some embodiments, the battery module described above can also be assembled into a battery pack, and the number of battery modules contained in the battery pack can be one or more, and a person skilled in the art can select a suitable number according to the application and capacity of the battery pack.

[0110] In the battery pack, a battery box and a plurality of battery modules arranged in the battery box can be included. The battery box includes an upper box body and a lower box body, and the upper box body can be arranged on the lower box body and form a closed space for accommodating the battery modules. The plurality of battery modules can be arranged in the battery box in any manner.

[0111] In addition, the application also provides a power utilization device, which includes the battery provided by the application. The battery can be used as a power supply of the power utilization device, or can be used as an energy storage unit of the power utilization device. The power utilization device can include a mobile device, an electric vehicle, an electric train, a ship and a satellite, an energy storage system, etc., but is not limited thereto. Among them, the mobile device can be a mobile phone, a notebook computer, etc.; the electric vehicle can be a pure electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, an electric bicycle, an electric scooter, an electric golf cart, an electric truck, etc., but is not limited thereto.

[0112] As the power utilization device, the battery can be selected according to the use requirement thereof.

[0113] FIG. 3 is a power utilization device 2 as an example. The power utilization device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle, etc. In order to meet the requirement of high power and high energy density of the battery for the power utilization device, a battery pack or a battery module can be used.

[0114] As another example of the device, it can be a mobile phone, a tablet computer, a notebook computer, etc. The device usually requires thinning, and a battery can be used as a power supply.

[0115] In order to make the technical problems, technical solutions and beneficial effects solved by the application clearer, the application will be further described in detail below in combination with embodiments and drawings. Obviously, the described embodiments are only a part of the embodiments of the application, rather than all the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and in no way limits the application and its applications. Based on the embodiments in the application, all other embodiments obtained by a person skilled in the art without creative labor fall within the scope of protection of the application.

[0116] Unless otherwise specified in the embodiments, the technology or conditions are carried out according to the technology or conditions described in the literature in the art or according to the product manual. Unless otherwise specified, the reagents or instruments used are conventional products that can be obtained from the market.

[0117] Embodiment 1

[0118] (1) Preparation of positive electrode sheet.

[0119] The positive electrode active material LiFePO4, conductive agent carbon black (Super P), and binder polyvinylidene fluoride (PVDF) were uniformly stirred in a proper amount of solvent NMP at a mass ratio of 97:1:2 to prepare a positive electrode slurry; the positive electrode slurry was uniformly coated on the surface of an aluminum foil, dried, cold-pressed, and then die-cut and slitted to prepare a positive electrode sheet. The aluminum foil had a breaking elongation of 7.2% and a thickness of 13 μm.

[0120] (2) Preparation of negative electrode sheet.

[0121] The negative electrode active material, conductive agent Super P, thickening agent (CMC), and binder (SBR) were added to a certain amount of water at a mass ratio of 95:3:1:1, uniformly stirred to prepare a negative electrode active slurry, and the negative electrode material included elemental silicon and graphite; the negative electrode active slurry was uniformly coated on the surface of a negative electrode composite current collector, dried, cold-pressed, and then die-cut and slitted to prepare a negative electrode sheet.

[0122] The negative electrode composite current collector included a PP support layer and a copper layer on the two opposite surfaces of the PP support layer. The thickness of the PP support layer was 4.5 μm, and the thickness of the single-sided copper layer was 1 μm. The total thickness of the negative electrode composite current collector was 6.5 μm.

[0123] (3) Preparation of separator.

[0124] A polyethylene film was used as a base film, and 3 μm thick aluminum trioxide was coated on the base film to obtain a separator.

[0125] (4) Preparation of electrolyte.

[0126] Lithium hexafluorophosphate was dissolved in a solvent of DMC:DEC:EC at a volume ratio of 1:1:1 to obtain a lithium ion battery electrolyte.

[0127] (5) Preparation of battery.

[0128] The positive electrode sheet, the negative electrode sheet, and the separator were wound into an electrode assembly, and then the battery cell in this example was obtained through processes such as packaging, liquid injection, and formation.

[0129] Examples 2-6

[0130] Compared with Example 1, the difference between Examples 2-6 was that the mass percentage of the silicon material in the negative electrode active material, the number average molecular weight of the PET, and the breaking elongation of the negative electrode composite current collector were different, as shown in Table 1.

[0131] Comparative Example 1

[0132] The difference between the comparative example and example 1 is that the positive current collector in the positive electrode tab is an aluminum foil. The breaking elongation of the aluminum foil is 7.2%, and the thickness is 13 μm. The negative current collector in the negative electrode tab is a copper foil. The breaking elongation of the copper foil is 2.3%, and the thickness is 6.5 μm.

[0133] Test Example

[0134] The damage to the negative current collector of the battery in the examples and the comparative example was tested by using an X-ray CT scanner to image after the capacity attenuation of every 5% SOH during the cycle of the battery monomer. If a crack appears in the tab in the two-dimensional image, it can be judged that the current collector is broken, and the SOH attenuation of the current collector cracking is recorded at this time. The results are shown in Table 1.

[0135] Table 1

[0136] As can be seen from Table 1, compared with Comparative Example 1, the negative composite current collector in Examples 1-6 does not crack during the cycle of the battery monomer, indicating that the introduction of the negative composite current collector can reduce the risk of damage to the negative current collector during the use of the battery monomer.

[0137] As can be seen from Examples 1-6, when the mass percentage of the silicon material in the negative active material is different, the negative composite current collector with a suitable breaking elongation can keep the negative composite current collector in a relatively stable structure without cracking during the cycle of the battery monomer. Further, as the mass percentage of the silicon material in the negative active material increases, the negative composite current collector with an increased breaking elongation can keep the negative composite current collector in a relatively stable structure without cracking during the cycle of the battery monomer.

[0138] The technical features of the above-described examples can be combined in any manner. To make the description concise, not all possible combinations of the technical features in the above-described examples are described, but as long as the combinations of the technical features do not contradict, they should be considered within the scope of the present disclosure.

[0139] The above-described examples only express several embodiments of the present application, and the description is relatively specific and detailed, but it should not be construed as limiting the scope of the patent. It should be noted that for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application. Therefore, the scope of the patent of the present application should be subject to the appended claims.

Claims

1. A battery cell, comprising an electrode assembly; the electrode assembly comprises a positive electrode tab, a negative electrode tab and a separator film between the positive electrode tab and the negative electrode tab; the negative electrode tab comprises a negative electrode composite current collector and a negative electrode active layer on at least one surface of the negative electrode composite current collector, the negative electrode composite current collector comprises a high molecular material support layer and a conductive layer on the surface of the high molecular material support layer.

2. The battery cell of claim 1, wherein, The negative electrode composite current collector has an elongation at break of ≥ 30%.

3. The battery cell of any one of claims 1-2, wherein, The negative electrode composite current collector has an elongation at break of 30%-150%.

4. The battery cell according to any one of claims 1 to 3, wherein, The electrode assembly is configured in a flat structure, and the electrode assembly comprises a flat part and a corner part arranged at both ends of the flat part.

5. The battery cell of claim 4, wherein, The minimum gap between the adjacent positive electrode tab and the negative electrode tab at the corner part is 20-40 μm at 97% SOC of the battery cell.

6. The battery cell of any one of claims 4-5, wherein, The minimum gap between the adjacent positive electrode tab and the negative electrode tab at the corner part is 30-80 μm at 3% SOC of the battery cell.

7. The battery cell according to any one of claims 1 to 6, wherein, The negative electrode active material of the negative electrode active layer comprises a silicon material.

8. The battery cell of claim 7, wherein, The mass percentage of the silicon material in the negative electrode active material is less than or equal to 5%, and the negative electrode composite current collector has an elongation at break of 60-100%.

9. The battery cell of claim 7, wherein, The mass percentage of the silicon material in the negative electrode active material is greater than 5% and less than or equal to 15%, and the negative electrode composite current collector has an elongation at break of 80-120%.

10. The battery cell of claim 7, wherein, The mass percentage of the silicon material in the negative electrode active material is greater than 15% and less than or equal to 25%, and the negative electrode composite current collector has an elongation at break of 90-130%.

11. The battery cell of claim 7, wherein, The mass percentage of the silicon material in the negative electrode active material is greater than 25% and less than or equal to 50%, and the negative electrode composite current collector has an elongation at break of 90-150%.

12. The battery cell of any one of claims 7-11, wherein, The silicon material comprises at least one of elemental silicon, silicon oxide compound, silicon-carbon composite, silicon-graphene composite material and silicon-carbon nanotube composite material.

13. The battery cell of any one of claims 1-12, wherein, The high molecular material support layer comprises a high molecular material, and the high molecular material has a number average molecular weight of 6000-9500.

14. The battery cell of claim 13, wherein, The high molecular material comprises at least one of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene and polyethylene.

15. The battery cell of claims 1-14, wherein, The battery cell comprises a shell for accommodating the electrode assembly.

16. The battery cell of claim 15, wherein, The shell has a square shape, and the shell comprises a shell body and at least one end cover; wherein the shell body has an opening at only one end, and the end cover covers the opening; or the shell body has an opening at both ends, and the two end covers cover the two openings respectively.

17. The battery cell of claim 15, wherein, The shell has a soft package structure, and the material of the shell comprises an aluminum plastic film.

18. The battery cell of claim 15, wherein, The shell has a cylindrical shape, and the shell comprises a shell body and at least one end cover, the end cover covers the opening of the shell body, and the outer diameter of the cylinder is greater than or equal to 30 mm. 19.A battery comprising the battery cell of any one of claims 1-18. 20.An electric device comprising at least one of the battery cell of any one of claims 1-18 and the battery of claim 19.

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