This study is led by Prof. Hui-Ming Cheng, Prof. Guangmin Zhou (Shenzhen Geim Graphene Center, Tsinghua-Berkeley Shenzhen Institute & Tsinghua Shenzhen International Graduate School, Tsinghua University) and Prof. Zheng Liang (Frontiers Science Center for Transformative Molecules, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University).
Li-ion battery is becoming the dominating power source in numerous applications and advanced recycling strategy is highly demanded in face of the rapidly-increasing numbers of retired batteries produced. Traditional recycling strategies are based on the structural destruction of the battery materials, starting from spent batteries and ending up with extracted metallic components with the aid of high temperature and/or highly corrosive agents. This process is lengthy, costly, and causes environmental problems. This issue intensifies recently with increasing number of spent batteries being generated each year as the electric vehicle industry continues booming.
To address it, a group led by Prof. Hui-Ming Cheng has proposed a novel direct-repairing method using a sustainable lithium-containing deep eutectic solvent (DES), which converts degraded LiCoO2 materials into regenerated LiCoO2 with excellent battery performance. Guided by theoretical simulations and analysis, a novel LiCl-CH4N2O DES was developed to compensate for the loss of Co and Li in degraded LiCoO2 under ambient pressure. The composition and structure of degraded LiCoO2 can be efficiently repaired by DES treatment and short annealing, and its electrochemical performance could be restored to its original state. The proposed method directly repairs the degraded LiCoO2 on the molecular scale, which significantly shortens the recycling process, reduces the pollution and lowers the cost.
The repaired LiCoO2 has an electrochemical performance comparable to that of pristine LiCoO2. The energy consumption, emission, cost and potential profit using this method are carefully calculated, and the results show that energy consumption is reduced by 37.1% and greenhouse gas emissions by 34.8% compared with the production of LiCoO2 from commercial precursors, and a higher benefit of up to 1.7 $/kg cell can be obtained, indicating high environmental and economic viability.
Researchers believe that the new direct recycling method has a great application prospect. Combined with the intelligent sorting and dismantling technology of spent LIBs, a directly recycling system for cathode materials might be built in the near future, and the production efficiency will be much higher than that of the existing recycling method. Higher economic benefit could also be achieved, and a sustainable chemistry in battery production could thus be realized.
See the article:
Direct and green repairing of degraded LiCoO2 for reuse in lithium-ion batteries
National Science Review