Green recycling process for spent lithium-ion batteries with extremely low chemical consumption

Lithium-ion batteries (LIBs), known for their superior electrochemical performance, are critical components in new energy vehicles and energy storage systems. With the development of the global new energy industry, LIBs, which have a service life of approximately 5 to 8 years, are entering their end-of-life phase. This is expected to generate a large number of spent batteries.

A typical LIB consists mainly of cathodes, anodes, separators, current collectors, and electrolyte. Commercial LIBs primarily use cathode materials like LiCoO₂, NCM and LiFePO₄, which contain valuable metals such as lithium, nickel, cobalt, and manganese. The electrolyte is usually composed of carbonate solvents and LiPF₆. Therefore, achieving efficient and low-consumption recycling of this urban mine is important for ensuring resource supply, reducing environmental pollution, and mitigating safety risks.

Recycling spent LIBs, however, is a complex engineering process involving multiple steps, such as pre-treatment, metallurgical extraction, separation, purification, and material regeneration. Although metallurgical routes have matured into established technological pathways and achieve large-scale production, they continue to face challenges posed by the rapidly updating battery materials, increasingly complex compositions, and continuously rising industry standards.

In a recent study led by Prof Zhi Sun from Institute of Process Engineering, Chinese Academy of Sciences, a novel mechanical activation assisted strategy, which can achieve the selective extraction of Li⁺ from spent cathode materials with highly utilization efficiency of H⁺ (>97%), was developed obviating the need for auxiliary reagents, and substantially reduces secondary pollutant generation.

The main findings, published in Fundamental Research, outlined:

1. Two leaching stages and one intermediate: The low reaction activity of the intermediate product from the initial leaching stage hinders the further leaching of Li⁺. The introduction of mechanical force has proven effective in significantly change these intermediates through activating spent cathode materials, thereby increasing the presence of defects and H⁺, which subsequently reduces the energy barrier for the second stage.

2. A novel mechanical activation assisted selective recycling technology was developed, which achieves a Li⁺ leaching efficiency exceeding 90% with high H⁺ utilization efficiency at 160 ºC. This technology is applicable not only to LiCoO₂ but also to various NCM cathodes and LiMn₂O₄. Demonstrating broad cathode material compatibility.

3. As cathode materials continue to develop, recycling technologies must accommodate a growing diversity of cathode types. Therefore, recycling technologies should possess broad applicability. While hydrothermal methods have already reached scalable production, mechanical ball milling still faces challenges in large-scale implementation.

Contact author:

Zhi Sun Institute of Process Engineering, Chinese Academy of Sciences, China, (sunzhi@ipe.ac.cn)

Funder:

This study acknowledge the support by the National Natural Science Foundation of China under Grant Nos. 51934006; 14th Five-year Information Plan of Chinese Academy of Sciences, Construction of Scientific Data Center System, Grant No.:WX145XQ07-12; Self-deployed Projects of Ganjiang Innovation Academy, Chinese Academy of Sciences (E055A002).

Conflict of interest: 

The authors declare that they have no conflicts of interest in this work.

See the article:

Lv, W.; Zheng, X.; Cao, H.; Wang, Y.; Ning, P.; Zhang, Y.; Sun, Z. A green recycling process for spent lithium-ion batteries with extremely low chemical consumption. Fundamental Research 2025, 5 (6), 2815-2823. DOI: 10.1016/j.fmre.2024.03.016