Manganese-doped regeneration lithium iron phosphate positive electrode material and method for preparing same

Abstract

The invention relates to a method for preparing a manganese-doped regeneration lithium iron phosphate positive electrode material. The method includes steps of 1), calcining waste lithium iron phosphate battery positive electrode materials, then stripping the lithium iron phosphate battery positive electrode materials from positive electrode current collectors, and sieving the lithium iron phosphate battery positive electrode materials to obtain waste positive electrode materials; 2), supplementarily adding lithium sources, iron sources, manganese sources and phosphorus sources into the wastepositive electrode materials according to the contents of elements in the waste positive electrode materials to allow a final molar ratio of the lithium sources to the iron sources to the manganese sources to the phosphorus sources to be 1.05:(0.9-0.99):(0.01-0.1):1, adding carbon sources into the waste positive electrode materials according to 1-25% of theoretical lithium iron phosphate output mass, carrying out wet ball-milling to obtain uniform mixtures; 3), calcining the uniform mixtures under the protection of inert atmosphere at the temperatures of 600-750 DEG C for 2-10 hours to obtainthe manganese-doped regeneration lithium iron phosphate positive electrode material. The method has the advantages that the method is simple in process and easy to scale up, the manganese-doped regeneration lithium iron phosphate positive electrode material prepared by the method is narrow in particle size distribution, good in electric conductivity, high in specific capacity, stable in cycle andexcellent in rate capability, and the method is suitable for industrially recycling waste lithium iron phosphate battery positive electrode materials on a large scale.

Description

technical field [0001] The invention belongs to the technical field of recovery and regeneration of waste lithium ion battery cathode materials, and in particular relates to a simple high-performance manganese-doped regenerated lithium iron phosphate cathode material and a preparation method thereof. Background technique [0002] The dramatic increase in the production of electric vehicle power batteries will cause some problems. First of all, it is the supply of lithium resources. Due to the uneven distribution of lithium ore around the world, my country's lithium ore reserves are relatively small and need to be imported from South American countries; once the upstream resources are cut off, it will lead to shocks in my country's power battery market. Secondly, electric vehicle power batteries contain a large amount of valuable metals and organic electrolytes. Once waste batteries cannot be effectively recycled, they will inevitably cause serious pollution to the environmen...

AI Technical Summary

Problems solved by technology

Although regenerated LiFePO can be obtained by different methods 4 positive electrode, but the performance of the product is still not ideal enough to reach commercial LiFePO 4 Positive technical indicators

Although currently for LiFePO 4 There have been a lot of work reports on the modification of cathode materials, but these modification technologies rely on the direct synthesis of LiFePO from raw materials. 4 , and whether they can also be used for waste LiFePO 4 The regeneration process of battery cathode materials is still unknown

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