Method for preparing a rechargeable biomass battery

Abstract

This invention discloses a method for preparing a rechargeable biomass battery, comprising the following steps: preparation of a negative electrode, preparation of a positive electrode, preparation of a quasi-solid-state gel electrolyte, and battery assembly. By employing gravity and a capillary wick to form a passive self-circulating structure, and supplementing it with a PVA borate quasi-solid-state gel electrolyte, a pump-free, corrosion-free, and leak-proof integrated sealed structure is achieved, significantly simplifying the system and improving safety. Furthermore, the preparation process does not require precious metal catalysts, effectively reducing preparation costs, improving electronic economy, and avoiding mutual restriction between the reaction rates of the cathode and anode. In addition, the positive and negative electrodes of the battery are modified negative and positive electrode sheets respectively, enabling the battery to achieve alcohol production through charging reduction and acid production through discharge oxidation under neutral conditions, while simultaneously achieving efficient and reversible energy storage. The reaction rates are not mutually restrictive, and the Faraday efficiency and cycle stability are significantly improved.

Description

Technical Field

[0001] This invention relates to the field of biomass batteries, and in particular to a method for preparing a rechargeable biomass battery. Background Technology

[0002] With the rapid development of the new energy industry and electrochemical energy storage technology, the large-scale grid connection of intermittent renewable energy sources such as wind power and photovoltaics, and the widespread application of civilian energy storage, portable power supplies, and distributed energy storage devices, the market has created an urgent demand for safe, low-cost, and environmentally friendly rechargeable batteries. Currently, mainstream commercial rechargeable batteries mainly include lithium-ion batteries, lead-acid batteries, and sodium-based batteries. Among them, lithium-ion batteries have excellent overall performance, but their production is highly dependent on rare mineral resources such as lithium, cobalt, and nickel. Mining, material preparation, and waste battery recycling can easily cause ecological pollution. Furthermore, these batteries pose safety hazards such as thermal runaway and combustion / explosion. Resource reserves and safety in use have become limiting factors for their large-scale promotion. Lead-acid batteries have lower costs, but lower energy density, shorter cycle life, and lead, a heavy metal, can easily cause serious environmental pollution. Other new energy storage batteries also generally suffer from problems such as scarce raw materials, complex manufacturing processes, and high operation and maintenance costs. Bio-based power sources, due to their advantages such as renewable raw materials, green and low-pollution characteristics, and good biocompatibility, have become a research hotspot in the energy storage field in recent years.

[0003] Current rechargeable biomass batteries generally suffer from the following problems: 1. The preparation of the negative electrode requires catalysts that rely on precious metals such as rhodium and ruthenium, resulting in high costs and difficulty in large-scale production; 2. The battery must use a strongly alkaline electrolyte, causing severe equipment corrosion and increased side reactions; 3. The battery requires an external liquid pump for forced circulation, making the system complex, energy-intensive, and prone to failure, with the liquid electrolyte easily leaking and evaporating, leading to poor environmental adaptability and safety; 4. The reaction rates of the cathode and anode are mutually restrictive, resulting in low electronic economics and low chemical production efficiency; 5. The open packaging structure of the battery makes integration difficult and results in low energy density per unit volume. Therefore, it is necessary to propose a new scheme to produce a low-cost, corrosion-free, pump-free, and highly stable rechargeable biomass battery. Summary of the Invention

[0004] In view of this, the present invention addresses the deficiencies of the prior art, and its main objective is to provide a method for preparing a rechargeable biomass battery. This method can effectively solve the problems of high preparation cost, easy corrosion of equipment, numerous side reactions, need for external pumps, poor adaptability and safety, and poor battery stability of existing rechargeable biomass batteries.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A method for preparing a rechargeable biomass battery includes the following steps: (1) Preparation of the negative electrode: (1a) Pretreatment of negative electrode current collector: The negative electrode current collector is placed in hydrochloric acid solution, anhydrous ethanol and deionized water in sequence for ultrasonic cleaning for 15 min. After being dried by nitrogen, the treated negative electrode current collector is obtained. (1b) Preparation of electrodeposition solution: Take 50 mL of deionized water, add copper salt, ferrous salt, first sodium salt and second sodium salt. The concentration of copper salt is 0.03-0.07 mol / L, the concentration of ferrous salt is 0.005-0.015 mol / L, the concentration of first sodium salt is 0.07-0.13 mol / L, and the concentration of second sodium salt is 0.03-0.07 mol / L. Stir for 30 min, then add acid-base adjuster to adjust the pH of the solution to 6.5-7.0 to obtain the electrodeposition solution; (1c) Electrodeposition treatment: A three-electrode system was adopted, with the treated negative electrode current collector obtained in step (1a) as the working electrode, a platinum sheet as the counter electrode, an Ag / AgCl electrode saturated with KCl as the reference electrode, and the electrodeposition solution obtained in step (1b) as the deposition solution. Constant current deposition was carried out at room temperature with a current density of (-25)-(-15) mA / cm² and a deposition time of 200-300s. After deposition, the treated negative electrode current collector was rinsed with deionized water 3 times and dried with nitrogen to obtain a negative electrode preform. (1d) Low-temperature annealing and crystallization: The negative electrode blank obtained in step (1c) is placed in a tube furnace and nitrogen gas is introduced. The flow rate of nitrogen gas is 100 sccm. Under the protection of nitrogen gas, the temperature is raised to 350℃ at 5℃ / min, held for 1h, and then naturally cooled to room temperature to obtain the negative electrode. (2) Preparation of the positive electrode: (2a) Pretreatment of positive electrode current collector: The positive electrode current collector is placed in hydrochloric acid solution, anhydrous ethanol and deionized water in sequence for ultrasonic cleaning for 15 min. After being dried by nitrogen, the treated positive electrode current collector is obtained. (2b) Preparation of hydrothermal fluid: Take 60 mL of deionized water, add nickel salt, manganese salt and nitrogen source. The amount of nickel salt added is 1-3 mmol, the amount of manganese salt added is 0.2-0.6 mmol and the amount of nitrogen source added is 6-10 mmol. Stir for 30 min to obtain hydrothermal fluid. (2c) Hydrothermal reaction: The treated positive electrode current collector obtained in step (2a) and the hydrothermal liquid obtained in step (2b) are transferred to a hydrothermal reactor and kept at 140°C for 8 hours. After natural cooling, the reactor is taken out and rinsed with deionized water 3 times. Then, it is vacuum dried at 60°C for 12 hours to obtain the positive electrode. (3) Preparation of quasi-solid gel electrolytes: Add 1g of polyvinyl alcohol to 10mL of deionized water and stir in a water bath until completely dissolved. The water bath temperature is 90℃. Then, cool down to 40℃ and add 5mL of borate buffer solution with a borate concentration of 0.5mol / L and a pH of 7.2. Stir until homogeneous. Then, add 20μL of glutaraldehyde solution with a mass fraction of 5wt% for crosslinking. Stir for 5min. Finally, pour into a mold and let stand for 2h to obtain PVA-borate quasi-solid electrolyte. (4) Battery assembly: The negative electrode obtained in step (1) and the positive electrode obtained in step (2) are cut into negative electrode sheets and positive electrode sheets respectively. Then, the PVA-borate quasi-solid electrolyte obtained in step (3) is cut into two parts. One part of the PVA-borate quasi-solid electrolyte is immersed in furfural solution with a concentration of 0.1 mol / L for 10 min to obtain negative electrode gel. The other part of the PVA-borate quasi-solid electrolyte is not immersed and is positive electrode gel. Then, the negative electrode sheet, negative electrode gel, separator, positive electrode gel and positive electrode sheet are stacked in sequence. Then, liquid storage tanks are set at the top and bottom and connected in the middle with capillary wicks. Passive circulation is achieved by using gravity and capillary action. Finally, the outer layer is sealed by hot pressing with PET film with a hot pressing pressure of 5 MPa, a hot pressing temperature of 80℃ and a hot pressing time of 30s to obtain a rechargeable biomass battery.

[0006] As a preferred embodiment, in step (1), the negative electrode current collector is copper foam.

[0007] As a preferred embodiment, in step (1), the copper salt is copper sulfate pentahydrate, the ferrous salt is ferrous sulfate heptahydrate, the first sodium salt is sodium dihydrogen phosphate, and the second sodium salt is sodium citrate.

[0008] As a preferred embodiment, in step (1), the acid-base regulator is sulfuric acid or sodium hydroxide.

[0009] As a preferred embodiment, in step (2), the positive current collector is nickel foam.

[0010] As a preferred embodiment, in step (2), the nickel salt is nickel nitrate hexahydrate, the manganese salt is manganese nitrate tetrahydrate, and the nitrogen source is urea.

[0011] Compared with the prior art, the present invention has obvious advantages and beneficial effects. Specifically, as can be seen from the above technical solution: By employing a gravity-driven capillary wick to form a passive self-circulating structure, supplemented by a PVA borate quasi-solid-state gel electrolyte, a pump-free, corrosion-free, and leak-proof integrated sealed structure is achieved, significantly simplifying the system and improving safety. Furthermore, the preparation process does not require precious metal catalysts, effectively reducing preparation costs and improving electronic economy. It also avoids the mutual restriction of reaction rates between the cathode and anode. In addition, the positive and negative electrodes of the battery are modified negative and positive electrodes, respectively, enabling the production of alcohol by charging reduction and the production of acid by discharging oxidation under neutral conditions, while simultaneously achieving efficient and reversible energy storage. The reaction rates are not mutually restrictive, and the Faraday efficiency and cycle stability are significantly improved.

[0012] To more clearly illustrate the structural features and effects of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the charging and discharging principle of the present invention; Figure 3 This is the LSV linear scan voltammetry curve of the present invention; Figure 4 This is an IV curve diagram of Embodiment 1 of the present invention; Figure 5 These are constant current charge-discharge curves of Embodiment 1 of the present invention under different current densities; Figure 6 This is a cyclic performance test curve of Embodiment 1 of the present invention. Detailed Implementation

[0014] This invention discloses a method for preparing a rechargeable biomass battery, which includes the following steps: (1) Preparation of the negative electrode: (1a) Pretreatment of negative electrode current collector: The negative electrode current collector is placed in hydrochloric acid solution, anhydrous ethanol and deionized water in sequence for ultrasonic cleaning for 15 min. After being dried by nitrogen, the treated negative electrode current collector is obtained; the negative electrode current collector is copper foam.

[0015] (1b) Preparation of electrodeposition solution: Take 50 mL of deionized water, add copper salt, ferrous salt, first sodium salt and second sodium salt. The concentration of copper salt is 0.03-0.07 mol / L, the concentration of ferrous salt is 0.005-0.015 mol / L, the concentration of first sodium salt is 0.07-0.13 mol / L, and the concentration of second sodium salt is 0.03-0.07 mol / L. Stir for 30 min, then add acid-base adjuster to adjust the pH of the solution to 6.5-7.0 to obtain the electrodeposition solution. The copper salt is copper sulfate pentahydrate, the ferrous salt is ferrous sulfate heptahydrate, the first sodium salt is sodium dihydrogen phosphate, the second sodium salt is sodium citrate, and the acid-base adjuster is sulfuric acid or sodium hydroxide. In order to accelerate the pH adjustment rate, sulfuric acid solution or sodium hydroxide solution is generally used, and the concentration of both is 1 mol / L.

[0016] (1c) Electrodeposition treatment: A three-electrode system was adopted, with the treated negative electrode current collector obtained in step (1a) as the working electrode, a platinum sheet as the counter electrode, an Ag / AgCl electrode saturated with KCl as the reference electrode, and the electrodeposition solution obtained in step (1b) as the deposition solution. Constant current deposition was carried out at room temperature with a current density of (-25)-(-15) mA / cm² and a deposition time of 200-300s. After deposition, the treated negative electrode current collector was rinsed with deionized water three times and dried with nitrogen to obtain a negative electrode preform.

[0017] (1d) Low-temperature annealing and crystallization: The negative electrode preform obtained in step (1c) is placed in a tube furnace and nitrogen gas is introduced at a flow rate of 100 sccm. Under the protection of nitrogen gas, the temperature is raised to 350°C at 5°C / min, held for 1 hour, and then naturally cooled to room temperature to obtain the negative electrode.

[0018] (2) Preparation of the positive electrode: (2a) Pretreatment of positive electrode current collector: The positive electrode current collector is placed in hydrochloric acid solution, anhydrous ethanol and deionized water in sequence for ultrasonic cleaning for 15 min. After being dried by nitrogen, the treated positive electrode current collector is obtained; the positive electrode current collector is nickel foam.

[0019] (2b) Preparation of hydrothermal fluid: Take 60 mL of deionized water, add nickel salt, manganese salt and nitrogen source. The amount of nickel salt added is 1-3 mmol, the amount of manganese salt added is 0.2-0.6 mmol and the amount of nitrogen source added is 6-10 mmol. Stir for 30 min to obtain hydrothermal fluid.

[0020] (2c) Hydrothermal reaction: The treated positive electrode current collector obtained in step (2a) and the hydrothermal liquid obtained in step (2b) are transferred to a hydrothermal reactor and kept at 140°C for 8 hours. After natural cooling, the electrode is taken out and rinsed three times with deionized water. Then, it is vacuum dried at 60°C for 12 hours to obtain the positive electrode. The nickel salt is nickel nitrate hexahydrate, the manganese salt is manganese nitrate tetrahydrate, and the nitrogen source is urea.

[0021] (3) Preparation of quasi-solid gel electrolytes: Add 1g of polyvinyl alcohol to 10mL of deionized water and stir in a water bath at 90℃ until completely dissolved. Then, cool to 40℃ and add 5mL of borate buffer solution with a borate concentration of 0.5mol / L and a pH of 7.2. Stir until homogeneous, then add 20μL of glutaraldehyde solution with a mass fraction of 5wt% for crosslinking. Stir for 5min and finally pour into a mold and let stand for 2h to obtain PVA-borate quasi-solid electrolyte.

[0022] (4) Battery assembly: The negative electrode obtained in step (1) and the positive electrode obtained in step (2) are cut into negative electrode sheets and positive electrode sheets respectively. The size of the negative electrode sheet and the positive electrode sheet is 2.0cm×2.0cm. Then, the PVA-borate quasi-solid electrolyte obtained in step (3) is cut into two parts. One part of the PVA-borate quasi-solid electrolyte is immersed in furfural solution with a concentration of 0.1mol / L for 10min to obtain negative electrode gel. The other part of the PVA-borate quasi-solid electrolyte is not immersed and is positive electrode gel. Then, the negative electrode sheet, negative electrode gel, separator, positive electrode gel and positive electrode sheet are stacked in sequence. Then, liquid storage tanks are set at the top and bottom and connected in the middle with capillary core. Passive circulation is achieved by using gravity and capillary action. Finally, the outer layer is sealed by hot pressing with PET film with a hot pressing pressure of 5 MPa, a hot pressing temperature of 80℃ and a hot pressing time of 30s to obtain a rechargeable biomass battery.

[0023] The following detailed description is based on specific embodiments.

[0024] Example 1 (1) Preparation of the negative electrode: (1a) Pretreatment of negative electrode current collector: The negative electrode current collector is placed in hydrochloric acid solution, anhydrous ethanol and deionized water in sequence for ultrasonic cleaning for 15 min. After being dried by nitrogen, the treated negative electrode current collector is obtained; the negative electrode current collector is copper foam.

[0025] (1b) Preparation of electrodeposition solution: Take 50 mL of deionized water, add copper salt, ferrous salt, first sodium salt and second sodium salt. The concentration of copper salt is 0.05 mol / L, the concentration of ferrous salt is 0.01 mol / L, the concentration of first sodium salt is 0.1 mol / L and the concentration of second sodium salt is 0.05 mol / L. Stir for 30 min, then add acid-base adjuster to adjust the pH of the solution to 7.0 to obtain electrodeposition solution. The copper salt is copper sulfate pentahydrate, the ferrous salt is ferrous sulfate heptahydrate, the first sodium salt is sodium dihydrogen phosphate, the second sodium salt is sodium citrate, and the acid-base adjuster is sulfuric acid or sodium hydroxide.

[0026] (1c) Electrodeposition treatment: A three-electrode system was adopted, with the treated negative electrode current collector obtained in step (1a) as the working electrode, a platinum sheet as the counter electrode, an Ag / AgCl electrode saturated with KCl as the reference electrode, and the electrodeposition solution obtained in step (1b) as the deposition solution. Constant current deposition was carried out at room temperature with a current density of -20mA / cm² and a deposition time of 300s. After deposition, the treated negative electrode current collector was rinsed with deionized water three times and dried with nitrogen to obtain a negative electrode preform.

[0027] (1d) Low-temperature annealing and crystallization: The negative electrode preform obtained in step (1c) is placed in a tube furnace and nitrogen gas is introduced at a flow rate of 100 sccm. Under the protection of nitrogen gas, the temperature is raised to 350°C at 5°C / min, held for 1 hour, and then naturally cooled to room temperature to obtain the negative electrode.

[0028] (2) Preparation of the positive electrode: (2a) Pretreatment of positive electrode current collector: The positive electrode current collector is placed in hydrochloric acid solution, anhydrous ethanol and deionized water in sequence for ultrasonic cleaning for 15 min. After being dried by nitrogen, the treated positive electrode current collector is obtained; the positive electrode current collector is nickel foam.

[0029] (2b) Preparation of hydrothermal fluid: Take 60 mL of deionized water, add nickel salt, manganese salt and nitrogen source. The amount of nickel salt added is 2 mmol, the amount of manganese salt added is 0.4 mmol and the amount of nitrogen source added is 8 mmol. Stir for 30 min to obtain hydrothermal fluid.

[0030] (2c) Hydrothermal reaction: The treated positive electrode current collector obtained in step (2a) and the hydrothermal liquid obtained in step (2b) are transferred to a hydrothermal reactor and kept at 140°C for 8 hours. After natural cooling, the electrode is taken out and rinsed three times with deionized water. Then, it is vacuum dried at 60°C for 12 hours to obtain the positive electrode. The nickel salt is nickel nitrate hexahydrate, the manganese salt is manganese nitrate tetrahydrate, and the nitrogen source is urea.

[0031] (3) Preparation of quasi-solid gel electrolytes: Add 1g of polyvinyl alcohol to 10mL of deionized water and stir in a water bath at 90℃ until completely dissolved. Then, cool to 40℃ and add 5mL of borate buffer solution with a borate concentration of 0.5mol / L and a pH of 7.2. Stir until homogeneous, then add 20μL of glutaraldehyde solution with a mass fraction of 5wt% for crosslinking. Stir for 5min and finally pour into a mold and let stand for 2h to obtain PVA-borate quasi-solid electrolyte.

[0032] (4) Battery assembly: The negative electrode obtained in step (1) and the positive electrode obtained in step (2) are cut into negative electrode sheets and positive electrode sheets respectively. The size of the negative electrode sheet and the positive electrode sheet is 2.0cm×2.0cm. Then, the PVA-borate quasi-solid electrolyte obtained in step (3) is cut into two parts. One part of the PVA-borate quasi-solid electrolyte is immersed in furfural solution with a concentration of 0.1mol / L for 10min to obtain negative electrode gel. The other part of the PVA-borate quasi-solid electrolyte is not immersed and is positive electrode gel. Then, the negative electrode sheet, negative electrode gel, separator, positive electrode gel and positive electrode sheet are stacked in sequence. Then, liquid storage tanks are set at the top and bottom and connected in the middle with capillary core. Passive circulation is achieved by using gravity and capillary action. Finally, the outer layer is sealed by hot pressing with PET film with a hot pressing pressure of 5 MPa, a hot pressing temperature of 80℃ and a hot pressing time of 30s to obtain a rechargeable biomass battery.

[0033] Example 2 (1) Preparation of the negative electrode: (1a) Pretreatment of negative electrode current collector: The negative electrode current collector is placed in hydrochloric acid solution, anhydrous ethanol and deionized water in sequence for ultrasonic cleaning for 15 min. After being dried by nitrogen, the treated negative electrode current collector is obtained; the negative electrode current collector is copper foam.

[0034] (1b) Preparation of electrodeposition solution: Take 50 mL of deionized water, add copper salt, ferrous salt, first sodium salt and second sodium salt. The concentration of copper salt is 0.03 mol / L, the concentration of ferrous salt is 0.015 mol / L, the concentration of first sodium salt is 0.07 mol / L and the concentration of second sodium salt is 0.07 mol / L. Stir for 30 min, then add acid-base adjuster to adjust the pH of the solution to 6.5 to obtain electrodeposition solution. The copper salt is copper sulfate pentahydrate, the ferrous salt is ferrous sulfate heptahydrate, the first sodium salt is sodium dihydrogen phosphate, the second sodium salt is sodium citrate, and the acid-base adjuster is sulfuric acid or sodium hydroxide.

[0035] (1c) Electrodeposition treatment: A three-electrode system was adopted, with the treated negative electrode current collector obtained in step (1a) as the working electrode, a platinum sheet as the counter electrode, an Ag / AgCl electrode saturated with KCl as the reference electrode, and the electrodeposition solution obtained in step (1b) as the deposition solution. Constant current deposition was carried out at room temperature with a current density of -15mA / cm² and a deposition time of 200s. After deposition, the treated negative electrode current collector was rinsed with deionized water three times and dried with nitrogen to obtain a negative electrode preform.

[0036] (1d) Low-temperature annealing and crystallization: The negative electrode preform obtained in step (1c) is placed in a tube furnace and nitrogen gas is introduced at a flow rate of 100 sccm. Under the protection of nitrogen gas, the temperature is raised to 350°C at 5°C / min, held for 1 hour, and then naturally cooled to room temperature to obtain the negative electrode.

[0037] (2) Preparation of the positive electrode: (2a) Pretreatment of positive electrode current collector: The positive electrode current collector is placed in hydrochloric acid solution, anhydrous ethanol and deionized water in sequence for ultrasonic cleaning for 15 min. After being dried by nitrogen, the treated positive electrode current collector is obtained; the positive electrode current collector is nickel foam.

[0038] (2b) Preparation of hydrothermal fluid: Take 60 mL of deionized water, add nickel salt, manganese salt and nitrogen source. The amount of nickel salt added is 2 mmol, the amount of manganese salt added is 0.5 mmol and the amount of nitrogen source added is 7 mmol. Stir for 30 min to obtain hydrothermal fluid.

[0039] (2c) Hydrothermal reaction: The treated positive electrode current collector obtained in step (2a) and the hydrothermal liquid obtained in step (2b) are transferred to a hydrothermal reactor and kept at 140°C for 8 hours. After natural cooling, the electrode is taken out and rinsed three times with deionized water. Then, it is vacuum dried at 60°C for 12 hours to obtain the positive electrode. The nickel salt is nickel nitrate hexahydrate, the manganese salt is manganese nitrate tetrahydrate, and the nitrogen source is urea.

[0040] (3) Preparation of quasi-solid gel electrolytes: Add 1g of polyvinyl alcohol to 10mL of deionized water and stir in a water bath at 90℃ until completely dissolved. Then, cool to 40℃ and add 5mL of borate buffer solution with a borate concentration of 0.5mol / L and a pH of 7.2. Stir until homogeneous, then add 20μL of glutaraldehyde solution with a mass fraction of 5wt% for crosslinking. Stir for 5min and finally pour into a mold and let stand for 2h to obtain PVA-borate quasi-solid electrolyte.

[0041] (4) Battery assembly: The negative electrode obtained in step (1) and the positive electrode obtained in step (2) are cut into negative electrode sheets and positive electrode sheets respectively. The size of the negative electrode sheet and the positive electrode sheet is 2.0cm×2.0cm. Then, the PVA-borate quasi-solid electrolyte obtained in step (3) is cut into two parts. One part of the PVA-borate quasi-solid electrolyte is immersed in furfural solution with a concentration of 0.1mol / L for 10min to obtain negative electrode gel. The other part of the PVA-borate quasi-solid electrolyte is not immersed and is positive electrode gel. Then, the negative electrode sheet, negative electrode gel, separator, positive electrode gel and positive electrode sheet are stacked in sequence. Then, liquid storage tanks are set at the top and bottom and connected in the middle with capillary core. Passive circulation is achieved by using gravity and capillary action. Finally, the outer layer is sealed by hot pressing with PET film with a hot pressing pressure of 5 MPa, a hot pressing temperature of 80℃ and a hot pressing time of 30s to obtain a rechargeable biomass battery.

[0042] Example 3 (1) Preparation of the negative electrode: (1a) Pretreatment of negative electrode current collector: The negative electrode current collector is placed in hydrochloric acid solution, anhydrous ethanol and deionized water in sequence for ultrasonic cleaning for 15 min. After being dried by nitrogen, the treated negative electrode current collector is obtained; the negative electrode current collector is copper foam.

[0043] (1b) Preparation of electrodeposition solution: Take 50 mL of deionized water, add copper salt, ferrous salt, first sodium salt and second sodium salt. The concentration of copper salt is 0.07 mol / L, the concentration of ferrous salt is 0.005 mol / L, the concentration of first sodium salt is 0.13 mol / L and the concentration of second sodium salt is 0.03 mol / L. Stir for 30 min, then add acid-base adjuster to adjust the pH of the solution to 7.0 to obtain electrodeposition solution. The copper salt is copper sulfate pentahydrate, the ferrous salt is ferrous sulfate heptahydrate, the first sodium salt is sodium dihydrogen phosphate, the second sodium salt is sodium citrate, and the acid-base adjuster is sulfuric acid or sodium hydroxide.

[0044] (1c) Electrodeposition treatment: A three-electrode system was adopted, with the treated negative electrode current collector obtained in step (1a) as the working electrode, a platinum sheet as the counter electrode, an Ag / AgCl electrode saturated with KCl as the reference electrode, and the electrodeposition solution obtained in step (1b) as the deposition solution. Constant current deposition was carried out at room temperature with a current density of -25mA / cm² and a deposition time of 200s. After deposition, the treated negative electrode current collector was rinsed with deionized water three times and dried with nitrogen to obtain a negative electrode preform.

[0045] (1d) Low-temperature annealing and crystallization: The negative electrode preform obtained in step (1c) is placed in a tube furnace and nitrogen gas is introduced at a flow rate of 100 sccm. Under the protection of nitrogen gas, the temperature is raised to 350°C at 5°C / min, held for 1 hour, and then naturally cooled to room temperature to obtain the negative electrode.

[0046] (2) Preparation of the positive electrode: (2a) Pretreatment of positive electrode current collector: The positive electrode current collector is placed in hydrochloric acid solution, anhydrous ethanol and deionized water in sequence for ultrasonic cleaning for 15 min. After being dried by nitrogen, the treated positive electrode current collector is obtained; the positive electrode current collector is nickel foam.

[0047] (2b) Preparation of hydrothermal fluid: Take 60 mL of deionized water, add nickel salt, manganese salt and nitrogen source. The amount of nickel salt added is 1.5 mmol, the amount of manganese salt added is 0.3 mmol and the amount of nitrogen source added is 8 mmol. Stir for 30 min to obtain hydrothermal fluid.

[0048] (2c) Hydrothermal reaction: The treated positive electrode current collector obtained in step (2a) and the hydrothermal liquid obtained in step (2b) are transferred to a hydrothermal reactor and kept at 140°C for 8 hours. After natural cooling, the electrode is taken out and rinsed three times with deionized water. Then, it is vacuum dried at 60°C for 12 hours to obtain the positive electrode. The nickel salt is nickel nitrate hexahydrate, the manganese salt is manganese nitrate tetrahydrate, and the nitrogen source is urea.

[0049] (3) Preparation of quasi-solid gel electrolytes: Add 1g of polyvinyl alcohol to 10mL of deionized water and stir in a water bath at 90℃ until completely dissolved. Then, cool to 40℃ and add 5mL of borate buffer solution with a borate concentration of 0.5mol / L and a pH of 7.2. Stir until homogeneous, then add 20μL of glutaraldehyde solution with a mass fraction of 5wt% for crosslinking. Stir for 5min and finally pour into a mold and let stand for 2h to obtain PVA-borate quasi-solid electrolyte.

[0050] (4) Battery assembly: The negative electrode obtained in step (1) and the positive electrode obtained in step (2) are cut into negative electrode sheets and positive electrode sheets respectively. The size of the negative electrode sheet and the positive electrode sheet is 2.0cm×2.0cm. Then, the PVA-borate quasi-solid electrolyte obtained in step (3) is cut into two parts. One part of the PVA-borate quasi-solid electrolyte is immersed in furfural solution with a concentration of 0.1mol / L for 10min to obtain negative electrode gel. The other part of the PVA-borate quasi-solid electrolyte is not immersed and is positive electrode gel. Then, the negative electrode sheet, negative electrode gel, separator, positive electrode gel and positive electrode sheet are stacked in sequence. Then, liquid storage tanks are set at the top and bottom and connected in the middle with capillary core. Passive circulation is achieved by using gravity and capillary action. Finally, the outer layer is sealed by hot pressing with PET film with a hot pressing pressure of 5 MPa, a hot pressing temperature of 80℃ and a hot pressing time of 30s to obtain a rechargeable biomass battery.

[0051] Example 4 (1) Preparation of the negative electrode: (1a) Pretreatment of negative electrode current collector: The negative electrode current collector is placed in hydrochloric acid solution, anhydrous ethanol and deionized water in sequence for ultrasonic cleaning for 15 min. After being dried by nitrogen, the treated negative electrode current collector is obtained; the negative electrode current collector is copper foam.

[0052] (1b) Preparation of electrodeposition solution: Take 50 mL of deionized water, add copper salt, ferrous salt, first sodium salt and second sodium salt. The concentration of copper salt is 0.05 mol / L, the concentration of ferrous salt is 0.012 mol / L, the concentration of first sodium salt is 0.12 mol / L and the concentration of second sodium salt is 0.05 mol / L. Stir for 30 min, then add acid-base adjuster to adjust the pH of the solution to 6.8 to obtain electrodeposition solution. The copper salt is copper sulfate pentahydrate, the ferrous salt is ferrous sulfate heptahydrate, the first sodium salt is sodium dihydrogen phosphate, the second sodium salt is sodium citrate, and the acid-base adjuster is sulfuric acid or sodium hydroxide.

[0053] (1c) Electrodeposition treatment: A three-electrode system was adopted, with the treated negative electrode current collector obtained in step (1a) as the working electrode, a platinum sheet as the counter electrode, an Ag / AgCl electrode saturated with KCl as the reference electrode, and the electrodeposition solution obtained in step (1b) as the deposition solution. Constant current deposition was carried out at room temperature with a current density of -18 mA / cm² and a deposition time of 250 s. After deposition, the treated negative electrode current collector was rinsed three times with deionized water and dried with nitrogen to obtain a negative electrode preform.

[0054] (1d) Low-temperature annealing and crystallization: The negative electrode preform obtained in step (1c) is placed in a tube furnace and nitrogen gas is introduced at a flow rate of 100 sccm. Under the protection of nitrogen gas, the temperature is raised to 350°C at 5°C / min, held for 1 hour, and then naturally cooled to room temperature to obtain the negative electrode.

[0055] (2) Preparation of the positive electrode: (2a) Pretreatment of positive electrode current collector: The positive electrode current collector is placed in hydrochloric acid solution, anhydrous ethanol and deionized water in sequence for ultrasonic cleaning for 15 min. After being dried by nitrogen, the treated positive electrode current collector is obtained; the positive electrode current collector is nickel foam.

[0056] (2b) Preparation of hydrothermal fluid: Take 60 mL of deionized water, add nickel salt, manganese salt and nitrogen source. The amount of nickel salt added is 1 mmol, the amount of manganese salt added is 0.6 mmol and the amount of nitrogen source added is 6 mmol. Stir for 30 min to obtain hydrothermal fluid.

[0057] (2c) Hydrothermal reaction: The treated positive electrode current collector obtained in step (2a) and the hydrothermal liquid obtained in step (2b) are transferred to a hydrothermal reactor and kept at 140°C for 8 hours. After natural cooling, the electrode is taken out and rinsed three times with deionized water. Then, it is vacuum dried at 60°C for 12 hours to obtain the positive electrode. The nickel salt is nickel nitrate hexahydrate, the manganese salt is manganese nitrate tetrahydrate, and the nitrogen source is urea.

[0058] (3) Preparation of quasi-solid gel electrolytes: Add 1g of polyvinyl alcohol to 10mL of deionized water and stir in a water bath at 90℃ until completely dissolved. Then, cool to 40℃ and add 5mL of borate buffer solution with a borate concentration of 0.5mol / L and a pH of 7.2. Stir until homogeneous, then add 20μL of glutaraldehyde solution with a mass fraction of 5wt% for crosslinking. Stir for 5min and finally pour into a mold and let stand for 2h to obtain PVA-borate quasi-solid electrolyte.

[0059] (4) Battery assembly: The negative electrode obtained in step (1) and the positive electrode obtained in step (2) are cut into negative electrode sheets and positive electrode sheets respectively. The size of the negative electrode sheet and the positive electrode sheet is 2.0cm×2.0cm. Then, the PVA-borate quasi-solid electrolyte obtained in step (3) is cut into two parts. One part of the PVA-borate quasi-solid electrolyte is immersed in furfural solution with a concentration of 0.1mol / L for 10min to obtain negative electrode gel. The other part of the PVA-borate quasi-solid electrolyte is not immersed and is positive electrode gel. Then, the negative electrode sheet, negative electrode gel, separator, positive electrode gel and positive electrode sheet are stacked in sequence. Then, liquid storage tanks are set at the top and bottom and connected in the middle with capillary core. Passive circulation is achieved by using gravity and capillary action. Finally, the outer layer is sealed by hot pressing with PET film with a hot pressing pressure of 5 MPa, a hot pressing temperature of 80℃ and a hot pressing time of 30s to obtain a rechargeable biomass battery.

[0060] Example 5 (1) Preparation of the negative electrode: (1a) Pretreatment of negative electrode current collector: The negative electrode current collector is placed in hydrochloric acid solution, anhydrous ethanol and deionized water in sequence for ultrasonic cleaning for 15 min. After being dried by nitrogen, the treated negative electrode current collector is obtained; the negative electrode current collector is copper foam.

[0061] (1b) Preparation of electrodeposition solution: Take 50 mL of deionized water, add copper salt, ferrous salt, first sodium salt and second sodium salt. The concentration of copper salt is 0.05 mol / L, the concentration of ferrous salt is 0.01 mol / L, the concentration of first sodium salt is 0.09 mol / L and the concentration of second sodium salt is 0.06 mol / L. Stir for 30 min, then add acid-base adjuster to adjust the pH of the solution to 6.7 to obtain electrodeposition solution. The copper salt is copper sulfate pentahydrate, the ferrous salt is ferrous sulfate heptahydrate, the first sodium salt is sodium dihydrogen phosphate, the second sodium salt is sodium citrate, and the acid-base adjuster is sulfuric acid or sodium hydroxide.

[0062] (1c) Electrodeposition treatment: A three-electrode system was adopted, with the treated negative electrode current collector obtained in step (1a) as the working electrode, a platinum sheet as the counter electrode, an Ag / AgCl electrode saturated with KCl as the reference electrode, and the electrodeposition solution obtained in step (1b) as the deposition solution. Constant current deposition was carried out at room temperature with a current density of -20mA / cm² and a deposition time of 220s. After deposition, the treated negative electrode current collector was rinsed with deionized water three times and dried with nitrogen to obtain a negative electrode preform.

[0063] (1d) Low-temperature annealing and crystallization: The negative electrode preform obtained in step (1c) is placed in a tube furnace and nitrogen gas is introduced at a flow rate of 100 sccm. Under the protection of nitrogen gas, the temperature is raised to 350°C at 5°C / min, held for 1 hour, and then naturally cooled to room temperature to obtain the negative electrode.

[0064] (2) Preparation of the positive electrode: (2a) Pretreatment of positive electrode current collector: The positive electrode current collector is placed in hydrochloric acid solution, anhydrous ethanol and deionized water in sequence for ultrasonic cleaning for 15 min. After being dried by nitrogen, the treated positive electrode current collector is obtained; the positive electrode current collector is nickel foam.

[0065] (2b) Preparation of hydrothermal fluid: Take 60 mL of deionized water, add nickel salt, manganese salt and nitrogen source. The amount of nickel salt added is 3 mmol, the amount of manganese salt added is 0.2 mmol and the amount of nitrogen source added is 6 mmol. Stir for 30 min to obtain hydrothermal fluid.

[0066] (2c) Hydrothermal reaction: The treated positive electrode current collector obtained in step (2a) and the hydrothermal liquid obtained in step (2b) are transferred to a hydrothermal reactor and kept at 140°C for 8 hours. After natural cooling, the electrode is taken out and rinsed three times with deionized water. Then, it is vacuum dried at 60°C for 12 hours to obtain the positive electrode. The nickel salt is nickel nitrate hexahydrate, the manganese salt is manganese nitrate tetrahydrate, and the nitrogen source is urea.

[0067] (3) Preparation of quasi-solid gel electrolytes: Add 1g of polyvinyl alcohol to 10mL of deionized water and stir in a water bath at 90℃ until completely dissolved. Then, cool to 40℃ and add 5mL of borate buffer solution with a borate concentration of 0.5mol / L and a pH of 7.2. Stir until homogeneous, then add 20μL of glutaraldehyde solution with a mass fraction of 5wt% for crosslinking. Stir for 5min and finally pour into a mold and let stand for 2h to obtain PVA-borate quasi-solid electrolyte.

[0068] (4) Battery assembly: The negative electrode obtained in step (1) and the positive electrode obtained in step (2) are cut into negative electrode sheets and positive electrode sheets respectively. The size of the negative electrode sheet and the positive electrode sheet is 2.0cm×2.0cm. Then, the PVA-borate quasi-solid electrolyte obtained in step (3) is cut into two parts. One part of the PVA-borate quasi-solid electrolyte is immersed in furfural solution with a concentration of 0.1mol / L for 10min to obtain negative electrode gel. The other part of the PVA-borate quasi-solid electrolyte is not immersed and is positive electrode gel. Then, the negative electrode sheet, negative electrode gel, separator, positive electrode gel and positive electrode sheet are stacked in sequence. Then, liquid storage tanks are set at the top and bottom and connected in the middle with capillary core. Passive circulation is achieved by using gravity and capillary action. Finally, the outer layer is sealed by hot pressing with PET film with a hot pressing pressure of 5 MPa, a hot pressing temperature of 80℃ and a hot pressing time of 30s to obtain a rechargeable biomass battery.

[0069] Example 6 (1) Preparation of the negative electrode: (1a) Pretreatment of negative electrode current collector: The negative electrode current collector is placed in hydrochloric acid solution, anhydrous ethanol and deionized water in sequence for ultrasonic cleaning for 15 min. After being dried by nitrogen, the treated negative electrode current collector is obtained; the negative electrode current collector is copper foam.

[0070] (1b) Preparation of electrodeposition solution: Take 50 mL of deionized water, add copper salt, ferrous salt, first sodium salt and second sodium salt. The concentration of copper salt is 0.04 mol / L, the concentration of ferrous salt is 0.009 mol / L, the concentration of first sodium salt is 0.09 mol / L and the concentration of second sodium salt is 0.06 mol / L. Stir for 30 min, then add acid-base adjuster to adjust the pH of the solution to 6.5 to obtain electrodeposition solution. The copper salt is copper sulfate pentahydrate, the ferrous salt is ferrous sulfate heptahydrate, the first sodium salt is sodium dihydrogen phosphate, the second sodium salt is sodium citrate, and the acid-base adjuster is sulfuric acid or sodium hydroxide.

[0071] (1c) Electrodeposition treatment: A three-electrode system was adopted, with the treated negative electrode current collector obtained in step (1a) as the working electrode, a platinum sheet as the counter electrode, an Ag / AgCl electrode saturated with KCl as the reference electrode, and the electrodeposition solution obtained in step (1b) as the deposition solution. Constant current deposition was carried out at room temperature with a current density of -20mA / cm² and a deposition time of 280s. After deposition, the treated negative electrode current collector was rinsed with deionized water three times and dried with nitrogen to obtain a negative electrode preform.

[0072] (1d) Low-temperature annealing and crystallization: The negative electrode preform obtained in step (1c) is placed in a tube furnace and nitrogen gas is introduced at a flow rate of 100 sccm. Under the protection of nitrogen gas, the temperature is raised to 350°C at 5°C / min, held for 1 hour, and then naturally cooled to room temperature to obtain the negative electrode.

[0073] (2) Preparation of the positive electrode: (2a) Pretreatment of positive electrode current collector: The positive electrode current collector is placed in hydrochloric acid solution, anhydrous ethanol and deionized water in sequence for ultrasonic cleaning for 15 min. After being dried by nitrogen, the treated positive electrode current collector is obtained; the positive electrode current collector is nickel foam.

[0074] (2b) Preparation of hydrothermal fluid: Take 60 mL of deionized water, add nickel salt, manganese salt and nitrogen source. The amount of nickel salt added is 2.5 mmol, the amount of manganese salt added is 0.5 mmol and the amount of nitrogen source added is 7 mmol. Stir for 30 min to obtain hydrothermal fluid.

[0075] (2c) Hydrothermal reaction: The treated positive electrode current collector obtained in step (2a) and the hydrothermal liquid obtained in step (2b) are transferred to a hydrothermal reactor and kept at 140°C for 8 hours. After natural cooling, the electrode is taken out and rinsed three times with deionized water. Then, it is vacuum dried at 60°C for 12 hours to obtain the positive electrode. The nickel salt is nickel nitrate hexahydrate, the manganese salt is manganese nitrate tetrahydrate, and the nitrogen source is urea.

[0076] (3) Preparation of quasi-solid gel electrolytes: Add 1g of polyvinyl alcohol to 10mL of deionized water and stir in a water bath at 90℃ until completely dissolved. Then, cool to 40℃ and add 5mL of borate buffer solution with a borate concentration of 0.5mol / L and a pH of 7.2. Stir until homogeneous, then add 20μL of glutaraldehyde solution with a mass fraction of 5wt% for crosslinking. Stir for 5min and finally pour into a mold and let stand for 2h to obtain PVA-borate quasi-solid electrolyte.

[0077] (4) Battery assembly: The negative electrode obtained in step (1) and the positive electrode obtained in step (2) are cut into negative electrode sheets and positive electrode sheets respectively. The size of the negative electrode sheet and the positive electrode sheet is 2.0cm×2.0cm. Then, the PVA-borate quasi-solid electrolyte obtained in step (3) is cut into two parts. One part of the PVA-borate quasi-solid electrolyte is immersed in furfural solution with a concentration of 0.1mol / L for 10min to obtain negative electrode gel. The other part of the PVA-borate quasi-solid electrolyte is not immersed and is positive electrode gel. Then, the negative electrode sheet, negative electrode gel, separator, positive electrode gel and positive electrode sheet are stacked in sequence. Then, liquid storage tanks are set at the top and bottom and connected in the middle with capillary core. Passive circulation is achieved by using gravity and capillary action. Finally, the outer layer is sealed by hot pressing with PET film with a hot pressing pressure of 5 MPa, a hot pressing temperature of 80℃ and a hot pressing time of 30s to obtain a rechargeable biomass battery.

[0078] Performance tests were conducted on the above-mentioned multiple embodiments, and the test results are shown in Table 1.

[0079]

[0080] Table 1 Analysis of the above data shows that the batteries in each embodiment exhibit a slow decay and stabilization trend during cycling: after 300 cycles, the capacity retention rate is above 95%; after 500 cycles, the capacity retention rate remains around 93%; after 800 cycles, the capacity decay rate slows down significantly, resulting in a capacity retention rate above 90.82% after 1000 charge-discharge cycles. Furthermore, the capacity retention rate of the corresponding embodiment after 1000 cycles is very close to its capacity retention rate after 800 cycles. Figure 6 It can be clearly concluded that during the early charge-discharge cycle, the capacity retention rate showed a slow downward trend, decreasing from 100% to approximately 92%. However, in the later stages, the capacity retention rate curve became significantly flatter, maintaining the capacity retention rate at 91%-92%. The performance degradation rate decreased significantly, indicating that the system had entered a stable cycle phase.

[0081] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the technical scope of the present invention. Therefore, any minor modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A method for preparing a rechargeable biomass battery, characterized in that: It includes the following steps: (1) Preparation of the negative electrode: (1a) Pretreatment of negative electrode current collector: The negative electrode current collector is placed in hydrochloric acid solution, anhydrous ethanol and deionized water in sequence for ultrasonic cleaning for 15 min. After being dried by nitrogen, the treated negative electrode current collector is obtained. (1b) Preparation of electrodeposition solution: Take 50 mL of deionized water, add copper salt, ferrous salt, first sodium salt and second sodium salt. The concentration of copper salt is 0.03-0.07 mol / L, the concentration of ferrous salt is 0.005-0.015 mol / L, the concentration of first sodium salt is 0.07-0.13 mol / L, and the concentration of second sodium salt is 0.03-0.07 mol / L. Stir for 30 min, then add acid-base adjuster to adjust the pH of the solution to 6.5-7.0 to obtain the electrodeposition solution; (1c) Electrodeposition treatment: A three-electrode system was adopted, with the treated negative electrode current collector obtained in step (1a) as the working electrode, a platinum sheet as the counter electrode, an Ag / AgCl electrode saturated with KCl as the reference electrode, and the electrodeposition solution obtained in step (1b) as the deposition solution. Constant current deposition was carried out at room temperature with a current density of (-25)-(-15) mA / cm² and a deposition time of 200-300s. After deposition, the treated negative electrode current collector was rinsed with deionized water 3 times and dried with nitrogen to obtain a negative electrode preform. (1d) Low-temperature annealing and crystallization: The negative electrode blank obtained in step (1c) is placed in a tube furnace and nitrogen gas is introduced. The flow rate of nitrogen gas is 100 sccm. Under the protection of nitrogen gas, the temperature is raised to 350℃ at 5℃ / min, held for 1h, and then naturally cooled to room temperature to obtain the negative electrode. (2) Preparation of the positive electrode: (2a) Pretreatment of positive electrode current collector: The positive electrode current collector is placed in hydrochloric acid solution, anhydrous ethanol and deionized water in sequence for ultrasonic cleaning for 15 min. After being dried by nitrogen, the treated positive electrode current collector is obtained. (2b) Preparation of hydrothermal fluid: Take 60 mL of deionized water, add nickel salt, manganese salt and nitrogen source. The amount of nickel salt added is 1-3 mmol, the amount of manganese salt added is 0.2-0.6 mmol and the amount of nitrogen source added is 6-10 mmol. Stir for 30 min to obtain hydrothermal fluid. (2c) Hydrothermal reaction: The treated positive current collector obtained in step (2a) and the hydrothermal liquid obtained in step (2b) are transferred to a hydrothermal reactor and kept at 140°C for 8 hours. After natural cooling, the electrode was removed and rinsed three times with deionized water. Then, it was vacuum dried at 60°C for 12 hours to obtain the positive electrode. (3) Preparation of quasi-solid gel electrolytes: Add 1g of polyvinyl alcohol to 10mL of deionized water and stir in a water bath until completely dissolved. The water bath temperature is 90℃. Then, cool down to 40℃ and add 5mL of borate buffer solution with a borate concentration of 0.5mol / L and a pH of 7.

2. Stir until homogeneous. Then, add 20μL of glutaraldehyde solution with a mass fraction of 5wt% for crosslinking. Stir for 5min. Finally, pour into a mold and let stand for 2h to obtain PVA-borate quasi-solid electrolyte. (4) Battery assembly: The negative electrode obtained in step (1) and the positive electrode obtained in step (2) are cut into negative electrode sheets and positive electrode sheets respectively. Then, the PVA-borate quasi-solid electrolyte obtained in step (3) is cut into two parts. One part of the PVA-borate quasi-solid electrolyte is immersed in furfural solution with a concentration of 0.1 mol / L for 10 min to obtain negative electrode gel. The other part of the PVA-borate quasi-solid electrolyte is not immersed and is positive electrode gel. Then, the negative electrode sheet, negative electrode gel, separator, positive electrode gel and positive electrode sheet are stacked in sequence. Then, liquid storage tanks are set at the top and bottom and connected in the middle with capillary wicks. Passive circulation is achieved by using gravity and capillary action. Finally, the outer layer is sealed by hot pressing with PET film with a hot pressing pressure of 5 MPa, a hot pressing temperature of 80℃ and a hot pressing time of 30s to obtain a rechargeable biomass battery.

2. The method for preparing a rechargeable biomass battery according to claim 1, characterized in that: In step (1), the negative current collector is copper foam.

3. The method for preparing a rechargeable biomass battery according to claim 1, characterized in that: In step (1), the copper salt is copper sulfate pentahydrate, the ferrous salt is ferrous sulfate heptahydrate, the first sodium salt is sodium dihydrogen phosphate, and the second sodium salt is sodium citrate.

4. The method for preparing a rechargeable biomass battery according to claim 1, characterized in that: In step (1), the acid-base regulator is sulfuric acid or sodium hydroxide.

5. The method for preparing a rechargeable biomass battery according to claim 1, characterized in that: In step (2), the positive current collector is nickel foam.

6. The method for preparing a rechargeable biomass battery according to claim 1, characterized in that: In step (2), the nickel salt is nickel nitrate hexahydrate, the manganese salt is manganese nitrate tetrahydrate, and the nitrogen source is urea.

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