Abstract: The short-process recycling of valuable metals in waste lithium-ion batteries is a key challenge for ensuring the supply of raw materials for the new energy industry. With the development of the new energy industry, achieving the short-process recycling of valuable metals in waste lithium-ion batteries is an important link in the new energy industry chain. Based on the basic principle of the sulfurization method, the thermodynamic analysis of the sulfurization of LiCoO2 positive electrode materials with three typical sulfurizing agents [S8, SO2, sulfide minerals (FeS, CuFeS2, ZnS)] was carried out using Factsage 7.3 thermodynamic software. The effects of sulfurization temperature and sulfurizing agent dosage on the sulfurization products were studied. Through software simulation calculations, it was proved that all sulfurizing agents can thermodynamically sulfurize LiCoO2. Li in LiCoO2 was sulfurized into water-soluble Li2S or Li2SO4, while Co generates sulfides or oxides that were insoluble in water. Through leaching separation experiments, efficient separation of Li and Co was achieved. The results of the sulfurization recovery experiment showed that the three types of sulfurizing agents can achieve different degrees of sulfurization on LiCoO2. Among them, S8 was affected by reaction kinetics and had the worst sulfurization effect, with a sulfurization rate of only 2.51%; SO2 had a poor sulfurization effect when used as a sulfurizing agent, with a sulfurization rate of 34.07%, while when SO2 and the reducing agent C synergistically sulfurize, the sulfurization rate increased significantly to 72.03%. When sulfide minerals were used as sulfurizing agents, ZnS showed the best sulfurization effect, with a sulfurization rate of 96.14%, while the sulfurization effects of both CuFeS2 and FeS were quite poor. This study can provide new ideas for the short-process recovery of valuable metals in waste Li-ion batteries.

Key words: lithium-ion battery, thermodynamics, selectivity, sulfidation recovery, Factsage

摘要： 短流程回收废旧锂离子电池中的有价金属是保障新能源产业原料供给的重点挑战方向。本工作基于硫化法基本原理，采用Factsage 7.3热力学软件，对三类典型硫化剂[S8、SO2、硫化矿(FeS, CuFeS2, ZnS)]硫化正极材料LiCoO2的过程开展热力学分析，系统研究了硫化温度、硫化剂用量对硫化产物的影响。结果表明，上述硫化剂在热力学上均可实现对LiCoO2的硫化，Li被硫化成水溶性的Li2S或Li2SO4，Co则生成难溶于水的硫化物或氧化物，结合浸出分离实验可实现Li与Co的高效分离。硫化回收实验研究表明，三类硫化剂对LiCoO2均可实现不同程度的硫化，其中S8受反应动力学影响，硫化效果最差，硫化率仅为2.51%；SO2单独作为硫化剂时硫化效果较差，硫化率为34.07%，而与还原剂C协同作用时，硫化率显著提升至72.03%；硫化矿中，ZnS的硫化效果最优，硫化率达96.14%，CuFeS2和FeS的硫化效果则相对较差。本研究可为短流程回收废旧锂离子电池中的有价金属提供新思路。

关键词: 锂离子电池, 热力学, 选择性, 硫化回收, Factsage