Due to its dual attributes of environment and resources, the development of green and low-carbon and the recycling of valuable metals have become a research hotspot in the field of spent lithium-ion batteries recycling. For the black mass, the reductant of Na2SO4 was selected to achieve efficient and preferential extraction of lithium by regulating the formation of the reduction products, investigating the mechanism of the synergy between in-situ carbothermal reduction and Na2SO4 roasting. The results demonstrated that the leaching efficiency of lithium from Black Mass was 80.93% under the optimal conditions of 20 g Na2SO4 dosage, roasting temperature of 700 ℃, and roasting time of 150 min. Comprehensive characterization revealed that the addition of Na2SO4 facilitated the transformation of Li from Li2CO3 to LiNaSO4, which has high solubility, and preventing the excessive reduction of Ni/Co oxides to the metallic states. The efficient separation and enrichment of lithium from spent LIBs was achieved by the accurate targeted transformation of the NCM during the synergistic roasting process, promising applications in the spent lithium-ion battery recycling industry.

中文翻译：

---

通过与 Na2SO4 协同焙烧优先从废旧锂离子电池中回收锂：精确调节


由于其环境和资源的双重属性，绿色低碳的发展和有价金属的回收已成为废旧锂离子电池回收领域的研究热点。对于黑色物质，选择 Na2SO4 的还原剂，通过调节还原产物的形成实现高效优先提取锂，研究原位碳热还原与 Na2SO4 焙烧之间的协同机制。结果表明，在Na2SO4添加量为20 g Na2SO4、焙烧温度为700 °C、焙烧时间为150 min的最佳条件下，Black Mass锂的浸出效率为80.93%。综合表征表明，Na2SO4 的添加促进了 Li 从 Li2CO3 转变为具有高溶解度的 LiNaSO4，并防止了 Ni/Co 氧化物过度还原为金属态。通过在协同焙烧过程中对 NCM 进行精确靶向转化，实现了废锂离子电池中锂的高效分离和富集，在废锂离子电池回收行业中具有广阔的应用前景。