A novel process for multi-stage continuous selective leaching of lithium from industrial-grade complicated lithium-ion battery waste

Abstract

Lithium-ion batteries are widely used in fields such as electric vehicles, portable electronic devices, energy storage systems, and medical equipment, and their indispensable and irreplaceable characteristics are highly regarded. However, extensive disposal of lithium-ion batteries occurs due to severe electrochemical property degradation. These waste batteries, as high-grade secondary resources, have become exceedingly valuable, especially given their lithium content far exceeding the mineable grade from conventional mining processes. Recovering this lithium not only contributes to the circular utilization of resources but also yields substantial economic benefits. This paper presents an innovative method that directly and selectively leaches lithium from industrial-grade composite lithium-ion battery waste. Unlike conventional methods, which require the separation of cathode active materials from other components, this method directly acts on complicated mixed powders, achieving a high leaching rate of lithium and exceptional leaching selectivity (Li extraction rate is higher than 96 %, while the extractions of iron, copper, aluminum, nickel, cobalt, and manganese are all lower than 1 %). Furthermore, a multi-stage continuous leaching process has been developed, enabling efficient selective leaching and enrichment of lithium from industrial-grade mixed waste materials. This method is suitable for various compositions of industrial lithium-ion battery waste and has demonstrated excellent industrial prospects in mini-pilot industrial experiments. Additionally, the paper investigates the washing, purification, and precipitation processes, resulting in a high-concentration and high-purity lithium-rich solution after four-stage washing and two-stage purification. And battery-grade lithium carbonate can be obtained after precipitation. Moreover, the economic evaluation calculations confirm that this method is profitable and feasible. This new method offers advantages such as high leaching rates, excellent selectivity, a streamlined process, low costs, wide applicability, environmental friendliness, and feasibility for industrialization. It represents efficient and sustainable technology with promising applications.