Direct recovery of LiCoO2 from the recycled lithium-ion batteries via structure restoration

The efficient reutilization of electrode materials in waste lithium-ion batteries (LIBs) is an urgent and tough problem that grows along with the rapid increase in the use of LIBs in various areas, including portable electronic products, electric vehicles and backup power supplies. Herein, we propose a promising way to recover the LiCoO2 positive electrode material from the recycled LIBs via structure restoration. The collected spent LiCoO2 powder is mixed with lithium salts and sintered to form a sophisticated layered structure. When Li2CO3 is added as the lithium source and the mole ratio of lithium to cobalt is controlled at 1.00 in the mixture, a layered structure of regenerated LiCoO2 could be preferably obtained at a calcination temperature of 800 degrees C. To improve the electrochemical performance of the regenerated LiCoO2, nanosized Al2O3 particles are coated on the surface of the regenerated LiCoO2. The Al2O3-coated and regenerated LiCoO2 demonstrates comparable properties to those of commercial LiCoO2 materials. The regeneration of spent LiCoO2 via structure restoration, which is demonstrated in the present study, provides an effective way to reuse cobalt metal directly without traditional leaching and re-synthesis procedures, which reduces energy consumption and contributes to the environmental protection. (C) 2020 Elsevier B.V. All rights reserved.