Green Recycling And Regeneration Of Lini0.5co0.2mn0.3o2 From Spent Lithium-Ion Batteries Assisted by Sodium Sulfate Electrolysis

Considering the necessity of green and sustainable recycling of spent lithium-ion batteries (LIBs). Herein, a green closed-loop leaching process based on electrolysis of sodium sulfate solution for recycling spent LIBs is demonstrated. The sulfuric acid and sodium hydroxide obtained by electrolyzing sodium sulfate solution are used as leaching agent. Under the optimal condition of that 2 vol% H2O2, 300 rpm stirring speed, 20 g L-1 pulp density and leaching temperature is 60 ℃, the leaching efficiencies for Ni, Co, Mn, and Li all reached more than 99 %. Spherical LiNi0.5Co0.2Mn0.3O2 particles are synthesized from the recycled Ni, Co, Mn, and Li by the carbonate co-precipitation method. The regenerated LiNi0.5Co0.2Mn0.3O2 has excellent electrochemical performance with the highest discharge specific capacity of 167.041 mAh g-1 in the first cycle, and stable rate performance and cycle performance (it retains 87% initial capacity after 100 cycles). The remained acid-based solution in the recycling process can be neutralized to form sodium sulfate and reused for electrolysis, the high-purity oxygen and hydrogen produced during the electrolysis have high added value. Finally, it is calculated that an economic outcome of $6992 is obtained by recycling one ton spent lithium-ion batteries