| Autor: |
Liu K; Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong 999077, China., Xu Z; Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong 999077, China., Wang M; Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong 999077, China., Alessi DS; Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta T6G 2R3, Canada., Tang Y; School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, United States., Tsang DCW; Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong 999077, China. |
| Abstrakt: |
Resource recovery from retired electric vehicle lithium-ion batteries (LIBs) is a key to sustainable supply of technology-critical metals. However, the mainstream pyrometallurgical recycling approach requires high temperature and high energy consumption. Our study proposes a novel mechanochemical processing combined with hydrogen (H 2 ) reduction strategy to accelerate the breakdown of ternary nickel cobalt manganese oxide (NCM) cathode materials at a significantly lower temperature (450 °C). Particle refinement, material amorphization, and internal energy storage are considered critical success factors for the accelerated decomposition of NCM cathode materials. In our proposed approach, NCM cathode materials can develop active sites with carbon defects (C v ) and oxygen vacancies (O v ), which improve the reduction and breakdown of H 2 . The adsorbed H 2 on the surface of NCM decomposes into H* and combines with oxygen to form OH species, which can be facilitated by O v via the enhanced charge transfer. The introduced C v can enhance H 2 cracking and generate *C-H species to promote the thermal decomposition of NCM. The presence of defects proves to foster the preferential reduction of Mn(IV) by H 2 , leading to a lower activation energy for the NCM decomposition (from 139 to 110 kJ/mol) with less H 2 consumption. Life cycle assessment suggests a reduction of 4.42 kg CO 2 eq for the recycling of every 1.0 kg of retired batteries. This study can promote material circularity and minimize the environmental burden of mining technology-critical metals for a low-carbon transition. |
