In-situ capacity regeneration of degraded lithium-ion batteries using remanufacturing remediator

Abstract

With the increasing application and production of lithium-ion batteries, the environmentally friendly and low-cost recycling of degraded lithium-ion batteries has become an urgent issue. Based on the battery degradation theory of active lithium loss, this work proposes a strategy for in-situ remanufacturing of degraded batteries through the injection of the 2,2,6,6-tetramethylpiperidine N-oxide (TEMPO) remediator to replenish the active lithium loss. The mechanism of TEMPO remediator initiated in-situ remanufacturing (TRIISR) strategy is sustainable activation of the inactive Li⁰ (lithium dendrites and dead lithium) to recover the degraded capacity. Moreover, TEMPO induces the LiF-rich solid electrolyte interphase (SEI) formation, further enhancing the dynamics and cycling stability of remanufactured batteries. Multiple characterizations and electrochemical tests corroborate the underlying mechanism of TRIISR according to the corresponding evolutions of structure and electrochemical performances of button cells. Based on this TRIISR strategy, the in-situ remanufactured commercial pouch cell exhibits a satisfactory capacity recovery of 5.89 % and a lifespan extension by 70 %. This work presents the simplicity TRIISR strategy with pro-environment, low-capacity loss rate, great techno-economic benefits due to the internal Li replenishment without damaging the cells. The insightful TRIISR strategy facilitates the secondary utilization of degraded batteries.