A kind of recycling method of lithium iron phosphate power battery

Abstract

The invention provides a method for recycling a lithium iron phosphate power battery. The method comprises the steps that discharging and disassembling of the lithium iron phosphate power battery are performed for separating out positive and negative electrode plates, a membrane and a shell, and the membrane and the shell are directly recycled; the negative electrode plate is smashed for ultrasonic and stirring treatment, filtering is performed and a copper sheet is recycled; after the positive electrode piece is smashed and screened, organic acid is used for performing a leaching reaction, filtering is performed to separate a solution containing lithium and aluminum from filter residues including organic acid ferric salt, carbon black, binding agents and the like; alkali liquor is added into the filtrate to obtain Al(OH)3 sediments which are separated from the solution containing lithium; the solution containing lithium is treated and then lithium can be recycled; after the lithium is recycled from the solution, the crystallization step is performed to obtain an organic acid sodium salt product. According to the method, the organic acid liquor is used for directly leaching iron and the like in the lithium iron phosphate positive electrode piece, the recycling technology is simplified, conventional equipment and raw materials are adopted, lithium, aluminum and copper of the lithium iron phosphate battery positive electrode material are economically, easily and conveniently recycled, and the organic acid sodium salt product with the high added value is obtained.

Description

technical field [0001] The invention belongs to the technical field of lithium ion battery recycling, and more specifically relates to a method for recycling lithium iron phosphate power batteries. Background technique [0002] Lithium iron phosphate battery has the advantages of stable structure, safe performance, high specific capacity, rich source of raw materials, and low price. It has been widely used in power batteries for electric vehicles, electric tools, etc., and has broad development prospects. Especially in the field of electric vehicles, in 2012, new energy vehicles were listed as one of the national strategic "seven emerging industries", and lithium iron phosphate materials were included in the national new material "twelfth five-year" development plan. Energy Saving and New Energy Automobile Industry Development Plan (2012-2020), it can be predicted that the production and sales of lithium-ion batteries using lithium iron phosphate as the cathode material will...

AI Technical Summary

Problems solved by technology

[0006] 1. When separating the aluminum foil in the positive plate, organic solvents are used to dissolve the binder, resulting in high cost and environmental pollution, and there is a hidden danger of harm to the human body

Or use a large amount of lye to completely dissolve the aluminum foil to separate it from the lithium iron phosphate material, and then use an acid solution to adjust the pH to recover the aluminum, resulting in a large amount of acid and lye used, high cost and cumbersome process (CN 103280610 A, etc.) ;

[0007] 2. Lithium iron phosphate materials are leached with conventional inorganic acids such as sulfuric acid, and then use lye to adjust the pH of the solution to precipitate and separate iron and lithium, but the entrainment loss of lithium is easily caused during precipitation and iron removal (CN 103280610 A, CN 102285673 A, CN103474719 A, etc. );

[0008] 3. Combine the positive electrode sheet and negative electrode material obtained by direct screening and cleaning into a new battery, but the waste positive electrode material is generally damaged and difficult to recycle through simple physical cleaning, making the recycled battery performance poor (CN102017276 B, etc.);

[0009] 4. Use high-temperature calcination to remove the positive electrode binder, carbon black or negative electrode graphite, which requires high energy consumption (CN101359756 B, CN 102017276 B, etc.)

Images