Additive-Regulated Strategy for Significant Enhancement in Lithium Recovery from Solid Electrolytes of All-Solid-State Lithium-Ion Batteries Using Green Low-Melting Mixture Solvents (LoMMSs)

High metal leaching efficiency from solid electrolytes is pivotal in determining the industrial application of recycling spent all-solid-state lithium-ion batteries (ASSLIBs). However, conventional methods to regulate leaching efficiency through controlling temperature and time can cause equipment corrosion and high energy consumption. Therefore, it is essential to develop a new strategy for tuning metal leaching efficiency. Here, we develop an additive-regulated strategy to tune the Li leaching efficiency from solid electrolytes Li6.5La3Zr1.5Ta0.5O12 of ASSLIBs by green low-melting mixture solvents. Results show that the additive-regulated strategy significantly enhances Li leaching efficiency from 33.5% to 87.0%, which corresponds to a 2.6-fold increase. In comparison, the improvement in Li leaching efficiency achieved through the regulation of the mole ratio, temperature, and time is less significant. Besides, metals in the leachate could be precipitated using antisolvents with a maximum precipitation efficiency of 97.6%. This work establishes an effective additive-regulated strategy for the efficient, mild, and sustainable recovery of solid electrolytes from ASSLIBs.