Method for producing bismuth trifluoride anode material of Li secondary battery

Abstract

The invention discloses a method for manufacturing a fluoride bismuth anode material in a lithium ion secondary battery, which comprises the following steps: 1) the bismuth salt is stirred for 1-10 hours until the bismuth salt is dissolved in the acetum solution of 5-45 per cent under the temperature of 0-50 DEG C, and then the solution of bismuth salt and the acetum is obtained; 2) surface active agent is added into the solution of bismuth salt and the acetum, and then the mixing solution of bismuth salt is obtained; 3) the soluble fluoride salt or the HF is dissolved in the 1-30 per cent ethanol water, and then the mixing solution of ethanol and fluoride is obtained; 4) the mixing solution of ethanol and fluoride obtained is dropped into the solution of bismuth salt and the acetum under a temperature of 0-45 DEG C, and a deposition of BiF3 is obtained; 5) the deposition of the BiF3 is filtered, washed and dried in the vacuum for 8-48 hours under the temperature of 45-100 DEG C to obtain the product of BiF3. The invention has the following beneficial effects: firstly, the acetic acid is used as solvent of Bi<3+> and the F<-> is directly added into the solvent. The BiF3 is prepared using the method of liquid phase deposition together. The obtained product has a high purity. The grain diameter can be controlled through adding surface active agent and controlling the time and the temperature of the deposition reaction. The solvent can be used repeatedly. Secondly, the product manufactured according to the method has the advantages of high purity, orderly grain crystal, good dispersivilty and good performance of discharging, and therefore the method is a novel, simple and high field manufacturing method for BiF3.

Description

technical field [0001] The invention relates to a preparation method of bismuth fluoride. Background technique [0002] The energy problem is a common problem faced by mankind in the 21st century. Electric energy is the most convenient form of energy. In order to store electric energy and meet the needs of the rapid development of the electronics industry and the development of electric vehicles, various types of batteries have emerged as the times require. Lithium secondary batteries are favored by the world for their high reversible capacity, high voltage, high cycle performance and high energy density. They are known as the leading power source in the 21st century, and their application fields continue to expand. However, the competition in the lithium secondary battery industry is very fierce. Finding new electrode materials with high performance and low cost is a powerful means to further reduce battery costs and enhance competitiveness. Therefore, research on new posi...

AI Technical Summary

Problems solved by technology

At present, the preparation of BiF in the world 3 The method is to react the oxide / sulfide / hydroxide of bismuth (III) in the gas-solid phase under the atmosphere of HF; 2 Reaction at a certain temperature, fluorine gas passes through bismuth (III) powder, and a gas-solid phase reaction occurs. This type of reaction consumes time and energy, and consumes high materials, so the resulting product is expensive.

Furthermore, BiF was synthesized by the classical solid-liquid reaction of bismuth hydroxide and hydrofluoric acid 3 It is theoretically feasible, but the actual yield is very low, there are many impurities, time-consuming and energy-consuming, and the impurity removal process is complicated, so the price of the product is also very expensive, and the reaction process cannot be controlled, the particle size of the product cannot be controlled, and the production conditions are difficult to control. The quality of the product is unstable, therefore, seeking a simple preparation method is BiF 3 As the key to the application of lithium secondary battery cathode materials

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