CN-117585655-B - Regeneration method of lithium iron phosphate positive electrode material waste and lithium ion battery

Abstract

The invention relates to a regeneration method of lithium iron phosphate positive electrode material waste and a lithium ion battery, and relates to the technical field of electronic waste recycling treatment, wherein the regeneration method of the lithium iron phosphate positive electrode material waste comprises the following steps of adding the lithium iron phosphate positive electrode material waste into a medium strong acid solution for acid leaching and dissolution, and filtering to obtain a transparent solution; the transparent solution is heated in a reflux way, filtered to obtain an iron-phosphorus product and a lithium-containing solution, the lithium-containing solution is treated to obtain a lithium salt product, the iron-phosphorus product, the lithium salt product and a carbon source are mixed, and then the mixture is baked in an inert atmosphere to obtain the LiFePO 4 /C composite material. The invention solves the problems of complex treatment process, high energy consumption, serious secondary pollution, more product impurities and low quality of regenerated products in the existing waste lithium iron phosphate battery treatment technology. Meanwhile, the regenerated positive electrode material finally obtained by the method can reach the battery level standard again.

Inventors

• LAI YIMING
• YANG YUNJIE
• WANG YONG
• GUO HONGXIANG
• ZHANG WENQI
• CHEN XIN
• HAN ZHENGXU

Assignees

• 华鼎国联四川动力电池有限公司

Dates

Publication Date

20260505

Application Date

20231120

Claims (3)

1. 1. The method for regenerating the lithium iron phosphate cathode material waste is characterized by comprising the following steps of: Adding lithium iron phosphate anode material waste into phosphoric acid solution for acid leaching and dissolving, and filtering to obtain transparent solution, wherein the concentration of phosphoric acid is 0.3-1.1 mol/L; the transparent solution is subjected to reflux heating and then filtered to obtain an iron-phosphorus product and a lithium-containing solution, wherein the operating parameters of the reflux heating comprise the temperature of 60-90 ℃ and the duration of 6-12 hours; Adding alkali into the lithium-containing solution to adjust the pH to 12-14, then introducing CO 2 gas or adding carbonate compound, filtering and drying to obtain a lithium salt product; Or, carrying out vacuum drying on the lithium-containing solution to obtain an oily viscous substance, mixing and dissolving the oily viscous substance and ethanol, and then filtering, washing and drying to obtain a lithium salt product; Mixing the iron and phosphorus products, the lithium salt products and a carbon source, and roasting in an inert atmosphere to obtain a LiFePO 4 /C composite material; the molar ratio of the iron-phosphorus product to the lithium salt product to the carbon source is 2 (1.05-1.15) and 0.3-0.5.
2. 2. The method of regenerating lithium iron phosphate positive electrode material waste according to claim 1, wherein the carbon source comprises at least one of glucose, sucrose, phenolic resin and carbon black.
3. 3. The method for regenerating lithium iron phosphate positive electrode material waste according to claim 1, wherein the roasting working parameters comprise 650-900 ℃ and 8-12 hours.

Description

Regeneration method of lithium iron phosphate positive electrode material waste and lithium ion battery Technical Field The invention relates to the technical field of electronic waste recycling treatment, in particular to a method for regenerating lithium iron phosphate positive electrode material waste and a lithium ion battery. Background With the wide popularization of new energy automobiles and the strong support of national policies, the new energy automobile market is greatly broken through. As an important power source of the new energy automobile, namely a lithium ion battery, the output of the lithium ion battery also gets a rapid leap. The lithium iron phosphate battery accounts for more than 60%, and the lithium iron phosphate battery keeps rapidly growing with the development of new energy automobiles and energy storage fields. However, since the cycle life of lithium ion batteries varies from 5 to 8 years, early-produced lithium iron phosphate batteries have been put into a scrapped period with the development of recent 10 years, and the scrapped yield thereof has increased with the expansion of the market scale. The lithium iron phosphate battery is rich in a large amount of metals such as Li, fe and the like, the dependence of the market on scarce resources such as Li and the like can be reduced through an effective recovery way, the recovered metal resources have considerable economical efficiency, in addition, a large amount of carbon dioxide generated in the battery production process is mainly distributed in a material manufacturing link, the carbon emission can be effectively reduced through recovering battery waste, and meanwhile, the waste lithium ion battery also contains a certain amount of organic binder, electrolyte and harmful lithium salt. Therefore, the waste lithium ion battery can effectively relieve the problems of metal resource shortage and environment, and has certain economic benefit. For recycling and regenerating lithium iron phosphate anode material waste, traditional pyrogenic and wet recycling processes both adopt a crashing recycling mode, after the battery is thoroughly crushed, a series of treatment modes such as smelting (the general temperature is more than or equal to 900 ℃) or strong acid are adopted to respectively obtain a molten alloy and a metal mixed solution, then a series of complex processes are adopted to carry out echelon separation to obtain raw materials of lithium and iron, mainly lithium salt and ferric salt, and finally, a new battery is prepared by starting at the beginning of the process, and the recycling way is adopted to easily cause waste of energy and resources. In addition, some processes currently propose adding lithium sources (Li 2CO3 and LiOH) to lithium iron phosphate waste materials to directly regenerate the lithium iron phosphate waste materials at high temperature, however, the regenerated materials obtained by the method have impurities and certain lattice defects, and are difficult to directly use as positive electrode materials. Therefore, it is necessary to develop a novel recovery way for treating lithium iron phosphate waste under relatively mild conditions, and the obtained recovery product has good quality and is directly used as a precursor for preparing lithium iron phosphate, so that the recycling of the lithium iron phosphate anode material is realized. Disclosure of Invention In order to solve the problems, the invention provides a method for regenerating lithium iron phosphate positive electrode material waste and a lithium ion battery. The invention aims to solve the problems of complex treatment process, high energy consumption, serious secondary pollution, more product impurities and low quality of regenerated products in the existing waste lithium iron phosphate battery treatment technology. Meanwhile, the method can effectively realize the conversion and recovery of the waste lithium iron phosphate battery anode material, and the finally obtained regenerated anode electrode material can reach the battery level standard again. In a first aspect, the present invention provides a method for regenerating lithium iron phosphate positive electrode material waste, the method comprising the steps of: Adding lithium iron phosphate anode material waste into a medium strong acid solution for acid leaching and dissolving, and filtering to obtain a transparent solution; reflux heating the transparent solution, and filtering to obtain an iron-phosphorus product and a lithium-containing solution; Treating the lithium-containing solution to obtain a lithium salt product; And mixing the iron and phosphorus products, the lithium salt products and the carbon source, and roasting in an inert atmosphere to obtain the LiFePO 4/C composite material. Further, the medium strong acid comprises phosphoric acid, and the concentration of the phosphoric acid is 0.3-1.1 mol/L. Further, the working parameters of the reflow heating comprise