Battery pole piece, battery and power device

Abstract

The utility model relates to the technical field of batteries, and discloses a battery pole piece, a battery and a power device. The battery pole piece comprises a current collector and an active material layer arranged on any surface of the current collector, and the active material layer comprises a first structural layer and a second structural layer. The first structural layer is located at the bottom layer and is in contact with the surface of the current collector, the first structural layer is prepared from a first active material, and the surface density of the first structural layer accounts for 20%-80% of the surface density of the active material layer; the second structural layer is located on the top layer away from the current collector and is prepared from a second active material, and the structural stability of the second active material is higher than that of the first active material. According to the utility model, the second structural layer positioned on the top layer can ensure the performance of the battery, and the first structural layer positioned on the bottom layer has low stability requirement and low cost, so that the cost can be reduced on the premise that the performance of the battery is not reduced.

Description

Technical Field

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

[0002] Lithium-ion batteries have the characteristics of high discharge voltage, high energy density and low self-discharge, and have been widely used in 3C products, electric vehicles and energy storage. In recent years, with the continuous improvement of energy conservation and environmental protection and other requirements, the demand for lithium-ion batteries in power batteries and other fields has increased rapidly.

[0003] At the same time, the market's requirements for battery energy and fast charging are getting higher and higher. How to reduce impedance and improve fast charging performance while meeting a certain energy density has become a technical problem in the industry. It is difficult to take into account all aspects of the performance of the battery cell, and cost considerations have also become the focus of the survival and development of enterprises.

[0004] Currently, the lithium-ion battery industry faces the problem of having difficulty achieving both improved long-term battery performance and reduced costs. Utility Model Content

[0005] In view of this, the utility model provides a battery electrode, a battery and a power device to solve the problem that it is difficult to achieve both improving the long-term performance of the battery and reducing the cost.

[0006] In the first aspect, the utility model provides a battery pole piece, including a current collector and an active material layer arranged on any surface of the current collector, the active material layer including at least two structural layers stacked on the current collector, including a first structural layer and a second structural layer. The first structural layer is located at the bottom layer close to the current collector and in contact with the surface of the current collector, the first structural layer is prepared by using a first active material; the surface density of the first structural layer accounts for 20% to 80% of the surface density of the active material layer; the second structural layer is located at the top layer away from the current collector, the second structural layer is prepared by using a second active material, and the structural stability of the second active material is higher than that of the first active material.

[0007] Beneficial effect: In the utility model, the second active material used in the second structural layer at the top layer is more stable than the first active material used in the first structural layer at the bottom layer, so that the second structural layer at the top layer can ensure the battery performance, and the first structural layer at the bottom layer has low stability requirements and low cost. Therefore, the utility model can achieve cost reduction without reducing the performance of the battery. By controlling the range of the surface density of the first structural layer to the surface density of the active material layer, it can be beneficial to the infiltration of the electrolyte while reducing the impedance of the battery cell.

[0008] In an optional embodiment, the compaction density of the first structural layer is higher than the compaction density of the second structural layer.

[0009] Beneficial effect: Since the first structural layer has a higher compaction density and a lower porosity, and the second structural layer has a lower compaction density and a higher porosity, it is beneficial to the electrolyte infiltration and the reduction of the cell impedance.

[0010] In an optional embodiment, the difference between the compaction density of the first structural layer and the compaction density of the second structural layer is 0.01 g / cm 3 To 0.1g / cm 3 within the range.

[0011] Beneficial effect: Such a setting can facilitate the infiltration of the electrolyte while reducing the impedance of the battery cell.

[0012] In an optional embodiment, the ratio of the surface density of the first structural layer to the surface density of the second structural layer is 3:7; or, the ratio of the surface density of the first structural layer to the surface density of the second structural layer is 4:6; or, the ratio of the surface density of the first structural layer to the surface density of the second structural layer is 5:5; or, the ratio of the surface density of the first structural layer to the surface density of the second structural layer is 6:4; or, the ratio of the surface density of the first structural layer to the surface density of the second structural layer is 7:3.

[0013] Beneficial effect: When the ratio of the surface density of the first structure layer to the surface density of the second structure layer is 5:5, the performance of the battery and the stability of equipment processing can be guaranteed; when the ratio of the surface density of the first structure layer to the surface density of the second structure layer is 3:7, 4:6, 6:4 or 7:3, such a proportional relationship can appropriately increase the design of the conductive agent content of the second structure layer to achieve battery performance requirements.

[0014] In an optional embodiment, the first structural layer is prepared by coating and then rolling; and / or the second structural layer is prepared by coating and then rolling.

[0015] Beneficial effect: The first structural layer or the second structural layer is prepared by rolling after coating, which is easy to ensure the above-mentioned control parameters.

[0016] In an optional embodiment, the current collector of the positive electrode sheet is aluminum foil; and the current collector of the negative electrode sheet is copper foil.

[0017] Beneficial effect: This arrangement meets the performance requirements of the positive and negative electrodes of the battery.

[0018] In an optional embodiment, the electrode sheet is a positive electrode sheet, and / or the electrode sheet is a negative electrode sheet.

[0019] Beneficial effect: When both the positive electrode sheet and the negative electrode sheet adopt the structure of the battery electrode sheet provided in the above technical solution, the battery performance can be guaranteed while the battery cost can be further reduced.

[0020] In a second aspect, the utility model further provides a battery, comprising a housing, an electrode group and an electrolyte. The electrode group is arranged in the housing, and the electrode group comprises a battery electrode sheet as described in any one of the above technical solutions; the electrolyte is filled in the housing, and the electrode group is immersed in the electrolyte.

[0021] Beneficial effect: Because the battery includes the battery pole piece in the above technical solution, the second structural layer of the battery pole piece is located at the top layer, and high-performance and high-stability materials are used to ensure battery performance. The first structural layer is located at the bottom layer, and relatively low-stability but lower-cost materials are used, thereby achieving cost reduction without reducing battery performance.

[0022] In an optional embodiment, the electrode group includes a positive electrode sheet, a negative electrode sheet, and a separator disposed between the positive electrode sheet and the negative electrode sheet, and the positive electrode sheet and the negative electrode sheet both adopt the battery electrode sheet described in any one of the above technical solutions.

[0023] Beneficial effect: Both the positive electrode and the negative electrode adopt the battery electrode in the above technical solution, which can further reduce the battery cost while ensuring the battery performance.

[0024] In a third aspect, the utility model also provides a power device, comprising the battery in the above technical solution.

[0025] Beneficial effects: Since the power device includes the battery in the above technical solution, it has all the beneficial effects of the battery and will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 This is a cross-sectional view of a battery electrode according to an embodiment of the utility model.

[0028] Description of reference numerals:

[0029] 1. Current collector; 2. Active material layer; 21. First structural layer; 22. Second structural layer. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.

[0031] Combine the following Figure 1 , describing an embodiment of the utility model.

[0032] According to an embodiment of the utility model, in the first aspect, a battery pole piece is provided, comprising a current collector 1 and an active material layer 2 arranged on any surface of the current collector 1, wherein the active material layer 2 comprises at least two structural layers stacked on the current collector 1, including a first structural layer 21 and a second structural layer 22. The first structural layer 21 is located at the bottom layer close to the current collector 1 and in contact with the surface of the current collector 1, and the first structural layer 21 is prepared by using a first active material; the surface density of the first structural layer 21 accounts for 20% to 80% of the surface density of the active material layer 2; the second structural layer 22 is located at the top layer away from the current collector 1, and the second structural layer 22 is prepared by using a second active material, and the structural stability of the second active material is higher than that of the first active material.

[0033] Specifically, the active material layer 2 is prepared by a multi-layer coating method, wherein the first structure layer 21 is the bottom layer and the second structure layer 22 is the top layer along the direction away from the current collector 1. As the bottom layer, the first structure layer 21 is in direct contact with the surface of the current collector 1.

[0034] For the battery pole piece, both surfaces of the current collector 1 are provided with active material layers 2, and at least one of the two active material layers 2 is prepared by a multi-layer coating method. Specifically, the active material layer 2 includes two or more structural layers. When the active material layer 2 is two structural layers, the active material layer 2 only includes the first structural layer 21 and the second structural layer 22. When the active material layer 2 is more than two structural layers, the active material layer 2 includes the first structural layer 21, the second structural layer 22, and the intermediate structural layer provided between the first structural layer 21 and the second structural layer 22. From the first structural layer 21 to the second structural layer 22, coating and superposition are performed in sequence.

[0035] In addition, the battery electrode includes a positive electrode and a negative electrode. The battery electrode provided in this embodiment is applicable to both positive electrode and negative electrode.

[0036] In a full battery, for the electrode structure, the top layer of the electrode has relatively high electrode potential and a relatively high degree of lithium insertion and extraction, so it has higher requirements for the structural stability of the material. The bottom layer has a relatively low electrode potential and a relatively low degree of lithium insertion and extraction, so it has relatively low requirements for the structural stability of the material. At the same time, the top layer material is in direct contact with the electrolyte to form SEI / CEI. In the later use of the battery, the SEI will be continuously damaged and repaired, so the chemical stability and structural stability of the top layer material are required to be higher. In the present utility model, the second active material used in the second structural layer 22 at the top layer is more stable than the first active material used in the first structural layer 21 at the bottom layer. Therefore, the second structural layer 22 at the top layer can ensure the battery performance, and the first structural layer 21 at the bottom layer has low stability requirements and low cost. Therefore, the present utility model can achieve cost reduction without reducing the performance of the battery.

[0037] When the active material layer 2 of the battery electrode is composed of two structural layers, namely, a first structural layer 21 and a second structural layer 22, and the surface density of the first structural layer 21 accounts for 20% of the surface density of the active material layer 2, the surface density of the second structural layer 22 accounts for 80% of the surface density of the active material layer 2.

[0038] When the active material layer 2 of the battery pole piece is a plurality of structural layers, that is, in addition to the first structural layer 21 and the second structural layer 22, at least one intermediate structural layer is included, then, when the surface density of the first structural layer 21 accounts for 20% of the surface density of the active material layer 2, the total surface density of the remaining structural layers accounts for 80% of the surface density of the active material layer 2. This arrangement can facilitate the infiltration of the electrolyte while reducing the impedance of the battery cell.

[0039] Specifically, for the positive electrode sheet, the positive electrode active material is selected from one or a combination of the following materials:

[0040] LiCoO2, LiMn2O4, LiMnO2, Li2MnO4, LiFePO4, Li1+aMn1-a-xMxO2, LiCo1-xMxO2, LiFe1-xMxPO4, LiMn2-yMyO4, Li2Mn1-xO4. Wherein, M is one or more selected from Ni, Co, Mn, Al, Cr, Mg, Zr, Mo, V, Ti, B, F and Y, 0≤a<0.2, 0≤x, y≤1.

[0041] The second structural layer 22 of the positive electrode must have high performance and high stability. The second active material includes but is not limited to ternary positive electrode materials produced by battery-grade lithium carbonate sintering process, such as NCM523, NCM622, NMC811, etc., which are fully coated and have excellent performance.

[0042] The first structural layer 21 of the positive electrode has low requirements on stability, and low-cost materials can be selected. The first active material includes but is not limited to low-cobalt or cobalt-free positive electrodes, di-sintered positive electrode materials, industrial-grade lithium carbonate precursor positive electrodes, etc.

[0043] Specifically, for the negative electrode sheet, the negative electrode active material is selected from one or a combination of the following materials:

[0044] Natural graphite, artificial graphite, soft carbon, hard carbon, lithium titanate, silicon, silicon-carbon alloy.

[0045] The second structural layer 22 of the negative electrode should have high performance and high stability. The second active material includes but is not limited to low-sulfur coke graphite and needle coke graphite, with complete coating and excellent performance.

[0046] The first structural layer 21 of the negative electrode has low requirements on stability, and low-cost materials can be selected. The first active material bottom layer is low-cost, including but not limited to natural graphite, medium-sulfur coke graphite, and coal-based coke graphite.

[0047] In one embodiment, the compaction density of the first structural layer 21 is higher than the compaction density of the second structural layer 22 .

[0048] Since the first structural layer 21 has a higher compaction density and a lower porosity, and the second structural layer 22 has a lower compaction density and a higher porosity, it is beneficial to electrolyte infiltration and reduction of cell impedance.

[0049] In one embodiment, the difference between the compaction density of the first structural layer 21 and the compaction density of the second structural layer 22 is 0.01 g / cm 3 To 0.1g / cm 3 within the range.

[0050] Such a configuration can facilitate the infiltration of the electrolyte while reducing the impedance of the battery cell.

[0051] In one embodiment, the ratio of the surface density of the first structure layer 21 to the surface density of the second structure layer 22 is 3:7; or, the ratio of the surface density of the first structure layer 21 to the surface density of the second structure layer 22 is 4:6; or, the ratio of the surface density of the first structure layer 21 to the surface density of the second structure layer 22 is 5:5; or, the ratio of the surface density of the first structure layer 21 to the surface density of the second structure layer 22 is 6:4; or, the ratio of the surface density of the first structure layer 21 to the surface density of the second structure layer 22 is 7:3.

[0052] When the ratio of the surface density of the first structural layer 21 to the surface density of the second structural layer 22 is 5:5, that is, in this embodiment, the active material layer 2 of the battery electrode is two structural layers, and the ratio of the surface density of the first structural layer 21 to the surface density of the second structural layer 22 is 1:1. This arrangement can ensure the performance of the battery and the stability of equipment processing.

[0053] When the ratio of the surface density of the first structure layer 21 to the surface density of the second structure layer 22 is 3:7, 4:6, 6:4 or 7:3, such a ratio relationship can appropriately increase the design of the conductive agent content of the second structure layer 22 to achieve battery performance requirements.

[0054] In one embodiment, the first structural layer 21 is prepared by coating and then rolling; and / or the second structural layer 22 is prepared by coating and then rolling.

[0055] The first structural layer 21 or the second structural layer 22 is prepared by rolling after coating, which is easy to ensure the above control parameters.

[0056] Specifically, the roller pressing may be performed once or twice, which may be determined according to the compaction density.

[0057] In one embodiment, the current collector 1 of the positive electrode sheet is aluminum foil; and the current collector 1 of the negative electrode sheet is copper foil.

[0058] This setting meets the performance requirements of the positive and negative electrodes of the battery.

[0059] In one embodiment, the electrode sheet is a positive electrode sheet, and / or the electrode sheet is a negative electrode sheet.

[0060] Specifically, in one embodiment, both the positive electrode sheet and the negative electrode sheet adopt the structure of the battery electrode sheet provided in the above embodiment, which can ensure the battery performance while further reducing the battery cost.

[0061] According to an embodiment of the utility model, in a second aspect, a battery is provided, comprising a housing, an electrode group and an electrolyte. The electrode group is arranged in the housing, and the electrode group comprises a battery electrode sheet as described in any one of the above technical solutions; the electrolyte is filled in the housing, and the electrode group is immersed in the electrolyte.

[0062] Because the battery includes the battery pole pieces in the above embodiments, the second structural layer 22 of the battery pole pieces is located at the top layer, and high-performance and high-stability materials are used to ensure battery performance, and the first structural layer 21 is located at the bottom layer, and relatively low-stability but lower-cost materials are used, thereby achieving cost reduction without reducing battery performance.

[0063] In one embodiment, the electrode group includes a positive electrode sheet, a negative electrode sheet, and a separator disposed between the positive electrode sheet and the negative electrode sheet, and the positive electrode sheet and the negative electrode sheet both adopt the battery electrode sheet described in any one of the above technical solutions.

[0064] Both the positive electrode and the negative electrode adopt the battery electrode in the above technical solution, which can further reduce the battery cost while ensuring the battery performance.

[0065] Specifically, the diaphragm is PE, PP / PE / PP isolation membrane, or any one of PE, PP / PE / PP isolation membranes treated with ceramic or PVDF.

[0066] The following provides three experimental cases and one comparative example of batteries, see Table 1. The battery pole pieces in the experimental examples are all made from the battery pole pieces provided in the above experimental examples. The battery pole pieces in the comparative example batteries are made using conventional single-layer coating, and the other preparation conditions are the same.

[0067] Table 1:

[0068]

[0069] The following performance tests are performed on the above cases:

[0070] 1. DC internal resistance test of lithium-ion secondary battery.

[0071] At 25°C, the lithium-ion secondary batteries prepared in Experimental Examples 1 to 3 and the comparative example were first charged to 4.35V at a constant current of 1C, and then further charged at a constant voltage of 4.35V to a current of 0.05C, and then discharged at a constant current of 0.5C for 1 hour, and the battery charge was maintained at 50% SOC. The battery was cooled to minus 20°C, left to stand for 60 minutes, and the voltage V1 was recorded. At this time, the battery was discharged at a current of I (I = 1C) for 10 seconds, and the discharge termination voltage V2 was recorded.

[0072] The calculation formula of the battery's discharge DC internal resistance DCIR is: DCIR = (V1-V2) / I (mΩ).

[0073] 2. High temperature cycle performance test of lithium-ion secondary batteries.

[0074] The high temperature cycle performance of the lithium ion secondary batteries prepared in Experimental Examples 1 to 3 and the comparative example was tested respectively. The specific method is as follows: at 45°C, the lithium ion secondary batteries were first charged to 4.35V at a constant current of 1C, then charged to a current of 0.05C at a constant voltage of 4.35V, and then discharged to 2.8V at a constant current of 1C. This is a charge and discharge cycle process, and the discharge capacity this time is the discharge capacity of the first cycle. The lithium ion secondary battery was subjected to a cyclic charge and discharge test in the above manner, and the discharge capacity of the 1000th cycle was taken. The capacity retention rate (%) of the lithium ion secondary battery after 1000 cycles = [discharge capacity of the 1000th cycle / discharge capacity of the first cycle] × 100%.

[0075] 3. High temperature storage performance test of lithium-ion secondary batteries.

[0076] At 25°C, the lithium ion secondary batteries prepared in Experimental Examples 1 to 3 and the comparative example are first charged to 4.35V with a constant current of 1C, and further charged to a current of 0.05C at a constant voltage of 4.35V, and then discharged to 2.8V at a constant current of 1C. The discharge capacity of this time is the discharge capacity of the lithium ion secondary battery before high-temperature storage; then the lithium ion secondary battery is charged to 4.35V with a constant current of 1C, and the lithium ion secondary battery is stored at 60°C for 90 days. After the storage is completed, the lithium ion secondary battery is placed in an environment of 25°C, and then discharged to 2.8V with a constant current of 0.5C, and then charged to 4.35V with a constant current of 1C, and further charged to a current of 1C at a constant voltage of 4.35V, and then discharged to 2.8V with a constant current of 1C. The last discharge capacity is the discharge capacity of the lithium ion secondary battery after high-temperature storage. Capacity retention rate of lithium ion secondary battery after high temperature storage (%)=[discharge capacity of lithium ion secondary battery after high temperature storage / discharge capacity of lithium ion secondary battery before high temperature storage]×100%.

[0077] 4. High temperature storage gas production performance test of lithium-ion secondary batteries.

[0078] At 25°C, the lithium-ion secondary batteries prepared in Experimental Examples 1 to 3 and the comparative example are first charged to 4.35V at a constant current of 1C, and then charged to a current of 0.05C at a constant voltage of 4.35V, and then discharged to 2.8V at a constant current of 1C. The discharge capacity is the discharge capacity of the lithium-ion secondary battery before high-temperature storage; then the lithium-ion secondary battery is charged to 4.35V at a constant current of 1C, and charged to a current of 0.05C at a constant voltage of 4.35V to fully charge the lithium-ion battery. The volume of the battery is tested by the drainage method, and the thickness of the battery is measured with a micrometer. The lithium-ion battery is then stored at 60°C for 90 days. After the storage is completed, the lithium-ion secondary battery is placed in a 25°C environment, and the volume of the battery is tested by the drainage method, and the thickness of the battery is measured with a micrometer. The lithium ion secondary battery is then discharged to 2.8V at a constant current of 0.5C, and then charged to 4.35V at a constant current of 1C, and further charged to a current of 1C at a constant voltage of 4.35V, and then discharged to 2.8V at a constant current of 1C. The last discharge capacity is the discharge capacity of the lithium ion secondary battery after high temperature storage.

[0079] Battery volume expansion rate = (volume after storage / volume before storage - 1)%.

[0080] The performance test results are shown in Table 2.

[0081] Table 2:

[0082]

[0083] It can be seen from the above table that since the positive electrode sheet and / or negative electrode sheet of the experimental example uses two structural layers and is formed by coating twice, the first structural layer 21 of the positive electrode sheet uses cost-reduced positive electrode material, and the first structural layer 21 of the negative electrode sheet uses cost-reduced natural graphite, which can achieve performance equivalent to that of the comparative example and simultaneously achieve cost reduction.

[0084] It can be seen that by adopting multiple structural layers and forming them by multiple coatings in the utility model, it is possible to reduce impedance under the premise of introducing cost-reducing materials and reducing system costs, while optimizing the long-term cycle and storage performance of the battery cell, thereby achieving a balance of performance in all aspects and achieving an effect equivalent to that of a single-layer high-performance material coating.

[0085] According to an embodiment of the present utility model, in a third aspect, a power device is also provided, comprising the battery in the above embodiment.

[0086] Since the power device includes the battery in the above embodiment, it has all the beneficial effects of the battery and will not be described in detail here.

[0087] Although the embodiments of the present invention are described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A battery pole piece, characterized in that: The invention comprises a current collector and an active material layer disposed on any surface of the current collector, wherein the active material layer comprises at least two structural layers stacked on the current collector, including: A first structural layer, located near the bottom layer of the current collector and in contact with the surface of the current collector, wherein the first structural layer is prepared by using a first active material; the surface density of the first structural layer accounts for 20% to 80% of the surface density of the active material layer; The second structural layer is located at the top layer away from the current collector. The second structural layer is formed by using a second active material. The structural stability of the second active material is higher than that of the first active material.

2. The battery electrode according to claim 1, characterized in that: The compaction density of the first structural layer is higher than the compaction density of the second structural layer.

3. The battery pole piece according to claim 2, characterized in that: The difference between the compaction density of the first structural layer and the compaction density of the second structural layer is within 0.01 g / cm 3 To 0.1g / cm 3 within the range.

4. The battery pole piece according to any one of claims 1 to 3, characterized in that: The ratio of the surface density of the first structural layer to the surface density of the second structural layer is 3:7; Or, the ratio of the surface density of the first structural layer to the surface density of the second structural layer is 4:6; Or, the ratio of the surface density of the first structural layer to the surface density of the second structural layer is 5:5; Or, the ratio of the surface density of the first structural layer to the surface density of the second structural layer is 6:4; Alternatively, the ratio of the surface density of the first structural layer to the surface density of the second structural layer is 7:

3.

5. The battery pole piece according to any one of claims 1 to 3, characterized in that: The first structural layer is prepared by coating and then rolling; and / or the second structural layer is prepared by coating and then rolling.

6. The battery pole piece according to any one of claims 1 to 3, characterized in that: The electrode sheet is a positive electrode sheet, and / or the electrode sheet is a negative electrode sheet.

7. The battery pole piece according to claim 6, characterized in that: The current collector of the positive electrode sheet is aluminum foil; the current collector of the negative electrode sheet is copper foil.

8. A battery, characterized in that: include: case; An electrode group, disposed in the housing, the electrode group comprising a battery electrode sheet according to any one of claims 1 to 7; The shell is filled with an electrolyte, and the electrode group is immersed in the electrolyte.

9. The battery according to claim 8, characterized in that The electrode group includes a positive electrode sheet, a negative electrode sheet, and a separator disposed between the positive electrode sheet and the negative electrode sheet. The positive electrode sheet and the negative electrode sheet are both the battery electrode sheet according to any one of claims 1 to 7.

10. A power device, characterized in that: A battery comprising the battery of claim 8 or 9.

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