Redox-Mediated Recycling of Spent Lithium-Ion Batteries Coupled with Low-Energy Consumption Hydrogen Production
Pengfei Zhu, Jiugang Hu, Jiugang Hu, Jie Hu, Jie Hu, Yi Yang, Wei Sun, Yue Yang, Guoqiang Zou, Hongshuai Hou, Xiaobo Ji
Abstract
Electrochemical recycling of spent lithium-ion batteries (sLIBs) is potentially cost-effective and consumes fewer chemicals than traditional metallurgical processes. However, severe side reactions and low system durability limit its practical applications. Herein, a redox-mediated electrochemical recycling strategy was developed for continuous Li extraction from spent LiFePO 4 (sLFP), coupled with low-energy-consumption hydrogen production. Phosphomolybdic acid (PMA) was employed as a green redox mediator to achieve fast and selective Li extraction from sLFP, and the reduced PMA was instantaneously electro-regenerated for subsequent extractions. In the assembled electrochemical flow cell, the Li recovery efficiency reached 97.8%, and the Faradaic efficiency of the hydrogen evolution reaction was approximately 100%. Furthermore, the redox-mediated sLFP-hydrogen coupling system required only 0.5 V of cell voltage to produce hydrogen, significantly lower than that of ∼1.65 V in the traditional water splitting process. This work presents a promising and sustainable route for the simultaneous recycling of sLIB and production of clean hydrogen fuels.