Recycling And Utilization Of Li,Ni And Co From Spent Lithium-ion Batteries By Wet Precess

Spent lithium-ion batteries?LIBs?have received widespread attention for its environmental hazards and resources.This paper proposes a wet process to recycle spent LIBs that using the ternary ammonia leaching system contains NH₃·H₂O,?NH₄?₂SO₃ and NH₄HCO₃ to selectively leach the target metal?Li,Ni,Co?from the cathode material of spent LIBs.Then,Cu as impurity can be specifically extracted by LIX984.Finally,the Li,Ni,and Co in the raffinate were co-precipitated to obtain the precursors Ni_0.5Co_0.5?OH?₂ and Li₂CO₃.The cathode material LiNi_0.5Co_0.5O₂ was synthesized by a two-stage heating method after precursor was mixed with lithium,which realizes the reuse of valuable metals in spent LIBs.The results show that under the condition of the composition of the leaching agent is 1.5mol·L^-1 ammonia,1 mol·L^-1 ammonium sulfite and 1 mol·L^-1 ammonium bicarbonate,the solid to liquid ratio is 20 g·L^-1,Ni and Cu could be almost fully leached out,while the leaching efficiency of Li and Co is 60.53%,80.99%,respectively.However,no matter how the leaching conditions are changed,Al is hardly leached.Its concentration in the leaching solution can be ignored due to its lower content in the cathode powder.The kinetic fit indicated that the leaching behavior of Co,Ni and Li seemed to be in good agreement with the reaction-controlled shrinking nucleus model,with activation energies of 59.99,53.53,and49.94 kJ·mol^-1,respectively.Cu can be specially separated by LIX984 from the highly alkaline ammonia solution in which multiple elements?Li,Co,Cu,Ni?coexist.Up to 97.85%of Cu and 2.89%of Ni are extracted by LIX984,while almost all the Li and Co remained in the liquid phase under the following optimum conditions:organic/aqueous phase ratio of 1,15%LIX984,and 25oC reaction for 10 min.The McCabe-Thiele fit indicated that two stages are required to completely extract Cu from the ammonia solution using 15%LIX984.The synthesized cathode material LiNi_0.5Co_0.5O₂ has high purity and good crystal.It displayed the initial charge and discharge capacities of 174.9 and 162.8 mAh·g^-1,respectively,together with excellent cycle performance.The specific discharge capacity remained at 145.8mAh·g^-1 and the discharge efficiency was 89.56%after 100 cycles.In summary,this process can effectively recover valuable metals of LIB,meanwhile,simplify the subsequent separation and purification process,which is a novel technology for the recycling of spent LIB and providing theoretical and technical support for the disposal and recycling of related electronic products,protecting the environment and bringing economic benefits.