A kind of regenerated positive electrode material and preparation method thereof and lithium ion battery comprising the regenerated positive electrode material

Abstract

The invention discloses a regenerated positive electrode material, a preparation method thereof and a lithium ion battery containing the regenerated positive electrode material. The method comprises the following steps: 1) taking out the positive electrode sheet after fully discharging the waste lithium ion battery; 2) placing the positive electrode sheet in a separation liquid to obtain a positive electrode active material; 3) placing the positive electrode active material in an alkaline solution to obtain Slurry; 4) After adding boric acid and additives to the slurry, add lithium sources and / or transition metals that need to be supplemented, dry and calcinate to obtain a regenerated positive electrode material. The method can achieve the purpose of uniform lithium supplementation, and at the same time, the regenerated positive electrode material prepared by the method has the same electrochemical performance as the newly prepared positive electrode material. Secondly, the preparation method of the present invention has simple process, low energy consumption, and does not harm the environment. It causes secondary pollution, is green and environmentally friendly, is conducive to large-scale promotion, and also provides a new idea for the recycling and reuse of waste batteries.

Description

technical field [0001] The invention relates to the technical field of waste battery recycling, in particular to a regenerated positive electrode material, a preparation method thereof and a lithium ion battery containing the regenerated positive electrode material. Background technique [0002] As an energy carrier, rechargeable lithium-ion batteries have been widely used in 3C, power supply and large power equipment and other fields. The optimization of the material preparation process, the strict control of the production process, and the improvement of the quality of employees have greatly improved the service life of lithium-ion batteries. However, the intricate physical and chemical reactions and complex environments that occur during the working process of lithium-ion batteries all pose a more severe test on their service life. [0003] As we all know, lithium-ion batteries are composed of positive electrode materials, separators, electrolytes, negative electrode mat...

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Problems solved by technology

CN102651490A discloses a method for regenerating positive electrode active materials of waste batteries. The positive electrode material stripped from the old positive electrode material pole sheet is regenerated through processes such as replenishing lithium source, sintering, pulverizing, and washing with water. However, it is used for soaking The separation solution of the positive electrode material is a flammable organic solvent such as N-methylpyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethyl sulfoxide, tetrahydrofuran, acetone, etc., and has a certain Toxicity; CN104466293A discloses a regeneration method of lithium cobalt oxide waste material of lithium ion battery positive electrode material, first dismantling waste lithium ion battery to obtain waste positive electrode sheet after fully discharging; waste positive electrode sheet is roasted, dissolved in water, and the waste cobalt obtained by filtering Lithium acid powder and potassium pyrosulfate are mixed in a certain proportion and then roasted; subsequently, the roasted product is leached with water, and filtered by adding potassium carbonate solution, and the resulting filter residue is supplemented with a certain amount of lithium carbonate, ball milled, compacted, and roasted in a resistance furnace. Regaining a lithium cobalt oxide positive electrode material with good electrochemical performance requires multiple roasting, and the process flow is complicated; CN104953200A discloses a lithium iron phosphate battery recovered from a lithium iron phosphate battery and the preparation of a battery-grade lithium iron phosphate by using waste lithium iron phosphate battery Lithium iron phosphate positive electrode material method, but the process needs to use a large amount of acid solution to fully dissolve the positive electrode material stripped from the current collector, and then precipitate it with an alkaline solution to obtain battery-grade iron phosphate, and further add a reducing agent, supplement After lithium is calcined at high temperature in an inert atmosphere, lithium iron phosphate is obtained, the process is more complicated and time-consuming

As we all know, lithium-ion battery cathode materials are obtained by high-temperature calcination, and the resulting products are crystalline phases with extremely high crystallinity. Hundreds or even thousands of charge-discharge cycles will cause local point defects and dislocations in the cathode materials. and other structural changes, but the positions of most atoms in the lattice remain unchanged, which makes it difficult for conventional lithium supplementation methods to achieve the desired effect. Even high-temperature calcination cannot ensure that the supplementary lithium diffuses to the expected position, resulting in Partial segregation, and the existing regenerated positive electrode materials prepared from waste batteries actually still have the above-mentioned problems

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