Functionalized MOF confined lithium nitrate additive and application thereof in lithium metal battery electrolyte

Abstract

The invention discloses a functionalized MOF confined lithium nitrate additive and application thereof in a lithium metal battery electrolyte, and belongs to the technical field of lithium metal batteries. According to the invention, amino-functionalized MOF (UiO-66-NH2) is used as a carrier, efficient loading and activation of LiNO3 are realized through a pore channel confinement effect and hydrogen bond interaction of amino and NO3 <->, and the problem of low solubility of LiNO3 in an ester electrolyte is solved; the modified electrolyte adopting the additive can remarkably improve the rate capability, the long cycle stability and the low-temperature adaptability of the lithium metal battery, and can still stably circulate at the extremely low temperature of-30 DEG C, so that a new scheme is provided for the practicability of the high-energy-density lithium metal battery.

Description

Technical Field

[0001] This invention belongs to the field of lithium metal battery technology, specifically relating to a functionalized metal-organic framework (MOF) confined lithium nitrate additive and its application in lithium metal battery electrolytes. Background Technology

[0002] With the increasing demand for high-energy-density energy storage devices in fields such as electric vehicles, portable electronic devices, and large-scale energy storage, lithium metal batteries have become increasingly popular due to their ultra-high theoretical capacity (3860 mAh g) from lithium metal anodes. -1 The highest energy density and lowest electrochemical reduction potential (-3.04 V vs. SHE) are widely recognized as the core development direction for next-generation high-energy-density battery systems. However, the inherent problem of poor interfacial stability between the lithium metal anode and the electrolyte severely restricts the commercial application of lithium metal batteries. During charge-discharge cycles, lithium metal is prone to continuous and uncontrollable side reactions with traditional commercial ester electrolytes, leading to repeated rupture, uneven growth, and continuous reconstruction of the solid electrolyte interface (SEI) on the electrode surface. This consumes a large amount of active lithium and electrolyte, resulting in a series of problems such as rapid capacity decay and significantly shortened cycle life.

[0003] Electrolyte additives are an efficient technique for regulating the composition and structure of the electrolyte interphase (SEI) and improving the compatibility of the electrode / electrolyte interface. Lithium nitrate (LiNO3), as a classic and efficient film-forming additive, can effectively stabilize the lithium metal anode interface and improve battery cycle performance. However, LiNO3 has extremely low solubility in ester electrolytes, the root cause of which lies in the Li... + With NO3 - There are extremely strong electrostatic interactions between them, making it difficult for them to fully dissociate in ester systems. This intrinsic defect greatly limits the practical application of LiNO3 in commercial ester electrolytes, making it difficult for it to fully exert its film-forming and interface-modifying effects.

[0004] Existing technologies for improving the solubility of LiNO3 have significant limitations: 1) Simple physical loading can only achieve surface adsorption and cannot fundamentally solve the problem of the intrinsic low solubility of LiNO3 in ester electrolytes; 2) Introducing cosolvents with a high donor number (such as dimethyl sulfoxide) can improve solubility to a certain extent, but such cosolvents are highly chemically active and easily undergo violent side reactions with lithium metal anodes, which can damage interfacial stability and exacerbate battery performance degradation.

[0005] Therefore, developing an electrolyte additive that can significantly improve the solubility and utilization of LiNO3 in ester electrolytes without introducing highly active co-solvents or damaging interfacial stability has become a key technical challenge that urgently needs to be solved in the field of lithium metal batteries. Summary of the Invention

[0006] To overcome the problems existing in the prior art, this invention provides a functionalized MOF-confined lithium nitrate (LiNO3) additive and its application in lithium metal battery electrolytes. This invention confines LiNO3 within the sub-nanopores of an amino-functionalized MOF, utilizing the amino functional groups modified on the pore surface to interact with NO3. - By precisely controlling the dissociation behavior of LiNO3 through weak interactions between the electrodes, the intrinsic low solubility of LiNO3 in ester electrolytes is fundamentally solved, while avoiding the risk of interfacial side reactions caused by the introduction of highly active co-solvents. The core objective of this invention is to provide a high-performance electrolyte additive that improves the electrode-electrolyte interface stability of lithium metal batteries, thereby significantly enhancing the cycle stability and rate performance of lithium metal batteries, and strengthening their adaptability to extreme low-temperature environments.

[0007] To achieve its objectives, the present invention employs the following technical solution: This invention first provides a method for preparing functionalized MOF-confined LiNO3 additives, comprising the following steps: Step 1: Preparation of UiO-66-NH2 material Zirconium tetrachloride and 2-amino-1,4-dicarboxylic acid were added to a mixture of N,N-dimethylformamide (DMF) and acetic acid and ultrasonically dispersed until the system was homogeneous. Then, trace amounts of deionized water were added. The resulting mixture was heated at 100–150 °C for 12–48 h. After the reaction was completed, the mixture was cooled to room temperature and centrifuged to collect the reaction product. The product was washed three times with DMF and ethanol, respectively, to remove residual impurities. Then, it was dried at 50–100 °C for 6–24 h and then vacuum activated at 150–200 °C for 6–24 h to obtain the amino-functionalized MOF material UiO-66-NH2.

[0008] Step 2: Dispersion and mixing of UiO-66-NH2 and LiNO3 solution The UiO-66-NH2 obtained in step 1 was ultrasonically dispersed in an organic solvent pre-dissolved with 0.1~2.0 M lithium nitrate (LiNO3) to obtain a mixed system; the organic solvent was selected from one or more of ethylene glycol dimethyl ether (DME) and acetonitrile (MeCN), preferably a low-boiling-point solvent with good solubility for LiNO3 and easy removal, such as ethylene glycol dimethyl ether (DME).

[0009] Step 3: Pore-confined loading and solvent removal of LiNO3 The mixture obtained in step 2 is placed at 20~60℃ (room temperature or heating method can be used) and stirred continuously for 6~48 h to ensure that LiNO3 diffuses fully and enters the sub-nano pores of the UiO-66-NH2 material; after stirring, the organic solvent in the system is removed by any one of the following methods: open stirring, heating volatilization, vacuum distillation or rotary evaporation, to obtain solid powder.

[0010] Step 4: Vacuum drying and composite material preparation The solid powder obtained in step 3 was placed in a vacuum environment and dried at 80~120℃ for 6~24 h to completely remove the residual organic solvent in the solid powder, and finally obtained UiO-66-NH2-LiNO3 composite material (i.e., the functionalized MOF confined LiNO3 additive described in this invention).

[0011] Preferably, in step 1, the molar ratio of zirconium tetrachloride to 2-amino-1,4-dicarboxylic acid is 1:1.

[0012] Preferably, in step 1, the amount of each raw material is as follows: based on a molar ratio of zirconium tetrachloride to 2-amino-1,4-dicarboxylic acid of 1:1, 50-75 mL of DMF, 8.85-17.7 mL of acetic acid, and 50 μL of deionized water are added for every 1 mmol of zirconium tetrachloride.

[0013] Preferably, in step 2, the mass ratio of UiO-66-NH2 to LiNO3 is (0.25~19):1.

[0014] The functionalized MOF-confined LiNO3 additive prepared according to the above method is composed of a functionalized MOF and LiNO3 confined within its sub-nanopores. The functionalized MOF is modified with organic ligands that can react with NO3. - The functional group that generates the interaction is specifically the amino group (-NH2). Compared to nitro (-NO2), carboxyl (-COOH), and fluorine (-F), the amino group can interact with NO3 in LiNO3. - The formation of optimally adapted hydrogen bonds can effectively weaken Li + With NO3 - The strong electrostatic binding energy of LiNO3, which promotes the dissociation of LiNO3 and thus enhances its solubility in ester electrolytes, is the core solution to the problem of low solubility of LiNO3.

[0015] The present invention also provides a lithium metal battery electrolyte comprising the above-mentioned additives, the electrolyte comprising: (1) Ester solvent: selected from one or more of carbonates, carboxylic acid esters or fluorinated carboxylic acid esters; wherein the carbonate is one or more of dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC) or ethylene carbonate (EC); wherein the carboxylic acid ester is one or more of methyl propionate (MP), methyl acetate (MA) or methyl formate (MF); wherein the fluorinated carboxylic acid ester is one or more of methyl fluoropropionate (FMP) or methyl fluoroacetate (FMA).

[0016] (2) Lithium salt: selected from one or more of lithium hexafluorophosphate (LiPF6), lithium bisfluorosulfonylimide (LiFSI), lithium bistrifluoromethanesulfonylimide (LiTFSI), and lithium difluorooxalate borate (LiDFOB), with a concentration of 0.5~3.0M in the electrolyte.

[0017] (3) MOF-LiNO3 additive: that is, the UiO-66-NH2-LiNO3 composite material obtained by the above preparation method of the present invention, the amount of which is added is 0.1~20 wt% of the total mass of the electrolyte.

[0018] (4) Optional components: To further optimize the film-forming properties of the electrolyte, one or more of fluoroethylene carbonate (FEC) and vinylene carbonate (VC) can be added to the electrolyte as film-forming additives, with the amount added accounting for 5 to 50 vol of the ester solvent volume.

[0019] This invention further provides a lithium metal battery, comprising a lithium metal negative electrode, a positive electrode, and the aforementioned lithium metal battery electrolyte containing the UiO-66-NH2-LiNO3 additive. The positive electrode material is selected from lithium iron phosphate (LiFePO4, LFP) and lithium nickel cobalt manganese oxide (LiNi). x Co y Mn 1-x-y O2, including NCM622, NCM811, NCM9055, etc.), lithium cobalt oxide (LiCoO2, LCO), lithium manganese oxide (LiMn2O4, LMO), or lithium-rich manganese-based materials, or one or more of these. The lithium metal anode is selected from pure lithium foil or composite lithium anodes supported on a three-dimensional framework, wherein the three-dimensional framework includes one or more of copper mesh and carbon fiber.

[0020] Compared with the prior art, the beneficial effects of the present invention are reflected in: 1. This invention uses functionalized MOF as the main structure, leveraging the confinement effect of the sub-nanometer pores inherent in MOF materials, and simultaneously utilizing the amino functional groups modified on the pore surface to interact with NO3. -The specific hydrogen bond interactions formed between them precisely regulate the dissociation and dispersion behavior of LiNO3 at the molecular level. Fundamentally different from traditional simple physical loading strategies, this invention achieves efficient dissolution and full activation of LiNO3 in ester electrolytes without the need for a high-donor-number co-solvent. It fundamentally solves the key technical problem of the extremely low intrinsic solubility of LiNO3 in ester electrolytes, hindering its practical application. It effectively avoids the side reactions and interfacial instability caused by highly active co-solvents with the lithium metal anode, significantly improving the compatibility of traditional commercial ester electrolytes with lithium metal anodes and providing a novel approach to improving the interfacial stability of lithium metal batteries.

[0021] 2. Using the UiO-66-NH2-LiNO3 composite material provided in this invention as an electrolyte additive, a dense, stable, and mechanically strong solid electrolyte interphase (SEI) film can be constructed in situ on the surface of the lithium metal anode. This effectively inhibits the uneven growth of lithium dendrites and the continuous decomposition of the electrolyte, significantly reducing interfacial impedance. The lithium metal battery assembled with this modified electrolyte not only possesses an ultra-long cycle life and excellent rate output performance at room temperature, but also achieves stable and efficient cycling operation under extreme low-temperature conditions of -30℃. This significantly expands the operating temperature range of lithium metal batteries, achieving a synergistic improvement in comprehensive electrochemical performance under long-cycle, high-rate, wide-temperature, and high-voltage conditions. Attached Figure Description

[0022] Figure 1 The Fourier transform infrared (FTIR) spectrum of the UiO-66-NH2 material and the UiO-66-NH2-LiNO3 composite material prepared in Example 1 of this invention; Figure 2 A comparison of the ionic conductivity of the composite materials (UiO-66-NH2-LiNO3 and UiO-66-LiNO3) prepared in Example 1 of this invention with different functional group modifications and saturated LiNO3 solutions in ester solvents. Figure 3 This is a comparison chart of the rate performance of Li||NCM811 half-cells using MOF-LiNO3 modified electrolyte and basic electrolyte in Example 2 of the present invention. Figure 4 This is a comparison chart of the high-rate (4 C) long-cycle performance of Li||NCM811 half-cells using modified electrolyte and basic electrolyte in Example 2 of this invention; Figure 5 This is a comparison chart of the long-cycle performance of Li||NCM811 full cells (N / P ratio = 2.8) using modified electrolyte and basic electrolyte in Example 2 of the present invention. Figure 6This is a performance comparison chart of Li||NCM811 half-cells using modified electrolyte and basic electrolyte in Example 2 of the present invention under a low temperature condition of -30℃. Detailed Implementation

[0023] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0024] Example 1: Comparison of preparation, structural characterization, and activation effects of MOF-LiNO3 composite materials with different functional groups 1. Preparation of MOF materials with two different functional groups First, the amino-functionalized MOF material (sample 1), the core of this invention, was prepared. Then, a non-functionalized MOF material was prepared as a comparison (sample 2). The specific preparation methods are as follows: Sample 1: Accurately weigh 0.2 mmol zirconium tetrachloride and 0.2 mmol 2-amino-1,4-dicarboxylic acid, and add them together to a container containing 12 mL DMF and 1.77 mL acetic acid. Disperse the mixture by sonication until homogeneous, then add 10 μL of deionized water. Transfer the resulting mixture to a 20 mL glass vial, seal it, and heat it at 120 °C for 24 h. After the reaction, cool to room temperature, centrifuge to collect the product, wash it three times sequentially with DMF and ethanol, dry it at 80 °C for 12 h, and then activate it under vacuum at 180 °C for 12 h to obtain the UiO-66-NH2 material.

[0025] Sample 2: To compare the effect of amino functional groups, 0.2 mmol of zirconium tetrachloride and 0.2 mmol of terephthalic acid were accurately weighed and synthesized as UiO-66 material without functional group modification according to the preparation method of Sample 1 above (same solvent amount, reaction conditions, washing and activation steps) for subsequent comparative testing.

[0026] 2. Preparation of two MOF-LiNO3 composite materials Using the same process, two MOF-LiNO3 composite materials were prepared, using sample 1 and sample 2 as carriers respectively: First, a 0.5 M LiNO3 / dimethyl ethylene glycol (DME) solution was prepared. 25 mg UiO-66-NH2 (sample 1) and 25 mg UiO-66 (sample 2) were accurately weighed and added to 2 mL of the above LiNO3 / DME solution. After ultrasonic dispersion, the mixture was stirred continuously at room temperature for 24 h to allow LiNO3 to fully diffuse and enter the sub-nanopores of the two MOFs.

[0027] After stirring, the DME solvent in the system was slowly removed by open stirring to obtain two solid powders. The two solid powders were then dried in a vacuum environment at 120°C for 12 h to completely remove the residual solvent, and finally two composite materials were obtained: UiO-66-NH2-LiNO3 (the target additive of this invention) and UiO-66-LiNO3 (comparative sample).

[0028] 3. Structural characterization The structure of UiO-66-NH2 material and its composite material UiO-66-NH2-LiNO3 was characterized by Fourier transform infrared spectroscopy (FTIR). The test results are as follows: Figure 1 As shown. By Figure 1 It can be seen that the characteristic peak of the NH stretching vibration of the amino group (-NH2) can be observed in the pure UiO-66-NH2 material; compared with the pure UiO-66-NH2, the characteristic peak of the amino group NH in the UiO-66-NH2-LiNO3 composite material shows a significant red shift. This characteristic phenomenon directly proves that the amino group reacts with the NO3- in LiNO3. - Hydrogen bonds formed between them.

[0029] 4. Ionic conductivity test To compare the activation effects of the two MOFs on LiNO3, three electrolytes were prepared: equal masses of LiNO3 particles, UiO-66-LiNO3 composite material, and UiO-66-NH2-LiNO3 composite material were taken and dispersed in a methyl propionate (MP) / fluoroethylene carbonate (FEC) mixed solvent with a volume ratio of 9:1, resulting in saturated LiNO3 solution, UiO-66-LiNO3 solution, and UiO-66-NH2-LiNO3 solution.

[0030] The three electrolytes were assembled into stainless steel symmetrical cells, and their ionic conductivity was measured using electrochemical impedance spectroscopy (EIS) in the frequency range of 0.1–10 Hz. 6 The test amplitude was 5 mV and the frequency was measured at Hz. The bulk resistance of the electrolyte was calculated by fitting the data, and then the ionic conductivity was obtained. The test results are as follows: Figure 2 As shown.

[0031] Depend on Figure 2 It can be seen that the electrolyte containing the UiO-66-NH2-LiNO3 composite material has a significantly higher ionic conductivity than the electrolyte containing the UiO-66-LiNO3 composite material and the saturated LiNO3 solution. This result indicates that the introduction of amino functional groups can enhance the ionic conductivity of the electrolyte by reacting with NO3-. - Hydrogen bonding is formed, which effectively promotes the dissociation of LiNO3 and thus improves the ionic conductivity of the electrolyte.

[0032] Example 2: Preparation of electrolyte and assembly and testing of lithium metal battery 1. Preparation of electrolyte Basic electrolyte: Lithium hexafluorophosphate (LiPF6) was dissolved in a 9:1 MP / FEC mixed solvent to prepare a basic electrolyte with a concentration of 1.0 M. After stirring evenly, the electrolyte was placed in an argon glove box for later use.

[0033] Modified electrolyte: The UiO-66-NH2-LiNO3 composite material prepared in Example 1 was added to the above basic electrolyte. The amount of additive added was controlled to be 10 wt% of the total mass of the electrolyte. After stirring evenly, the modified electrolyte was obtained and placed in an argon glove box for later use.

[0034] 2. Battery assembly Half-cell: In an argon glove box (oxygen level <0.01 ppm), lithium metal foil was used as the negative electrode, NCM811 electrode as the positive electrode, and Celgard 2325 and GF / A as separators. The two electrolytes mentioned above were injected to assemble two sets of CR2032 coin-type Li||NCM811 half-cells, which were then sealed and kept for later use: the control group battery was injected with the basic electrolyte; the experimental group battery was injected with the modified electrolyte.

[0035] Full cell: at 0.2 mA cm -2 Electrochemical deposition of Li metal on Cu foil at a given current density yielded an areal capacity of 6.8 mAh cm⁻¹. -2 The negative electrode has a surface capacity of 2.4 mAh cm⁻¹. -2 The NCM811 electrode was used as the positive electrode to assemble Li||NCM811 full cells with an N / P ratio of 2.8 (one experimental group and one control group) for long-cycle performance comparison testing of full cells. The assembly process was the same as described above, and the corresponding electrolytes were injected respectively.

[0036] 3. Electrochemical performance comparison test The experimental and control group batteries were placed under the same test conditions for rate performance, high-rate long-cycle performance, full-cell long-cycle performance, and low-temperature performance tests. The test results are as follows: Figures 3-6 As shown, the specific comparison is as follows: (1) Half-cell rate performance comparison test Test conditions: temperature 28℃, voltage range 3.0~4.3 V; test rates were C / 3, C / 2, 1 C, 4 C, 6 C, 10 C, 5 cycles at each rate, and finally returned to C / 3 rate.

[0037] Comparison results: by Figure 3As can be seen, the experimental group batteries exhibited good discharge specific capacity at all rates, especially at high rates of 4 C and above, where the discharge specific capacity was significantly higher than that of the control group batteries; the control group batteries showed a sharp drop in discharge specific capacity at high rates, failing to achieve stable output. This comparative result proves that the modified electrolyte of this invention can effectively improve the rate performance of batteries, solving the defect of poor high-rate performance of basic electrolytes.

[0038] (2) Comparative test of high-rate long-cycle performance of half-cell Test conditions: temperature 28℃, voltage range 3.0~4.3 V, test rate 4 C, continuous cycle test 1000 times.

[0039] Comparison results: by Figure 4 As can be seen, after 1000 cycles, the experimental group of batteries still maintained a capacity retention rate of 77.0%, with no significant capacity decay, demonstrating excellent high-rate long-cycle stability. In contrast, after 600 cycles, the control group of batteries showed a capacity retention rate of only 71.4%, with rapid capacity decay. This indicates that the modified electrolyte of this invention can effectively stabilize the electrode-electrolyte interface, suppress side reactions such as lithium dendrite growth and electrolyte decomposition, and significantly improve the long-cycle performance of the battery.

[0040] (3) Comparative test of long-cycle performance of full battery Test conditions: temperature 28℃, voltage range 3.0~4.3 V, test rate 0.5 C, continuous cycle test 400 times.

[0041] Comparison results: by Figure 5 As can be seen, after 400 cycles, the experimental group of batteries maintained a capacity retention rate of 81.0%, demonstrating stable operation; while the control group of batteries showed significant capacity decay after 150 cycles, with a capacity retention rate of less than 70%. This indicates that the additive of this invention can be effectively adapted to the full battery system, significantly improving the long-cycle stability of the full battery and possessing good practical application value.

[0042] (4) Comparative test of low-temperature performance of half-cell Test conditions: temperature -30℃ (extreme low temperature conditions), voltage range 3.0~4.5 V (high voltage conditions), test rate 0.1 C, continuous cycle test 250 times.

[0043] Comparison results: by Figure 6 As can be seen, after 250 cycles, the experimental group of batteries still maintained a capacity retention rate of 84.3%, with no significant capacity decay, and could cycle stably in extreme low-temperature environments. In contrast, the control group of batteries could not operate stably at -30℃, and their capacity completely decayed after less than 20 cycles. This proves that the modified electrolyte of this invention can effectively improve the adaptability of lithium metal batteries in extreme low-temperature environments and significantly broaden the battery's operating temperature range.

[0044] Based on the above performance test results, it can be seen that, compared with the control group battery without the additives of this invention, the experimental group battery using the MOF-LiNO3 modified electrolyte of this invention shows significant advantages in terms of ionic conductivity, rate performance, long cycle performance, and low temperature adaptability, effectively solving many defects of existing basic electrolytes.

Claims

1. A method for preparing functionalized MOF-confined lithium nitrate additives, characterized in that, Includes the following steps: Step 1: Zirconium tetrachloride and 2-amino-1,4-dicarboxylic acid were added to a mixture of N,N-dimethylformamide and acetic acid. After ultrasonic dispersion, deionized water was added. The mixture was reacted at 100-150℃ for 12-48 h. After cooling, the product was collected by centrifugation, washed with DMF and ethanol, dried, and then activated under vacuum at 150-200℃ to obtain the amino-functionalized MOF material UiO-66-NH2. Step 2: The UiO-66-NH2 obtained in Step 1 is ultrasonically dispersed in an organic solvent containing LiNO3 to obtain a mixed system; Step 3: Stir the mixture obtained in Step 2 at 20~60℃ for 6~48 h to allow LiNO3 to enter the MOF channels; after stirring, remove the solvent to obtain solid powder. Step 4: The solid powder obtained in Step 3 is vacuum dried at 80~120℃ for 6~24 h to obtain UiO-66-NH2-LiNO3 composite material, which is the functionalized MOF-confined lithium nitrate additive.

2. The preparation method according to claim 1, characterized in that, In step 1, the molar ratio of zirconium tetrachloride to 2-amino-1,4-dicarboxylic acid is 1:

1.

3. The preparation method according to claim 2, characterized in that, The ratio of raw materials used in step 1 is as follows: based on a molar ratio of zirconium tetrachloride to 2-amino-1,4-dicarboxylic acid of 1:1, each 1 mmol of zirconium tetrachloride corresponds to the addition of 50~75 mL of N,N-dimethylformamide, 8.85~17.7 mL of acetic acid, and 50 μL of deionized water.

4. The preparation method according to claim 1, characterized in that, In step 2, the mass ratio of UiO-66-NH2 to LiNO3 is 0.25~19:

1.

5. The preparation method according to claim 1 or 4, characterized in that, In step 2, the concentration of LiNO3 in the organic solvent is 0.1~2.0 M.

6. The preparation method according to claim 1, characterized in that, In step 2, the organic solvent is selected from one or more of ethylene glycol dimethyl ether and acetonitrile.

7. A functionalized MOF-confined lithium nitrate additive, characterized in that, The additive is prepared by the preparation method described in any one of claims 1 to 6.

8. A lithium metal battery electrolyte, characterized in that, The additive includes ester solvents, lithium salts, and the functionalized MOF-confined lithium nitrate additive as described in claim 7, wherein the amount of the additive added is 0.1 to 20 wt% of the total mass of the electrolyte.

9. A lithium metal battery, characterized in that, It includes a lithium metal anode, a cathode, and the electrolyte as described in claim 8.

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