Tailoring carbon chains for repairing graphite from spent lithium-ion battery toward closed-circuit recycling

Graphite, as a strategic mineral resource, the recycling from spent lithium-ion batteries (LIBs) has attracted considerable attention for meeting considerable economic value. However, closed-circuit recycling still suffers from the lack of effective repair methods. Considering the existing defects, a series of C-chain length carbons have been successfully introduced to repair spent graphite. Obviously, with the evolution of carbon resources, the thickness and pores of the coating layer were tailored with the functional groups. Benefitting from the increased active sites and created fold structure, their coulombic efficiency is obviously restored from 14% to 86.89%, while the stable capacity is kept at approximately 384.9 mAh g−1 after 100 cycles. Moreover, their excellent rate properties are kept about approximately 200 mAh g−1 at 2 C, meeting the standard of commercial materials. Supported by the detailed kinetic behaviors, the enhanced rate is mainly dominated by pseudocapacitive behaviors, accompanied by deepening redox reactions. Meanwhile, the cost of the proposed approach for recycling spent graphite is 894.87 $ t−1, and the recycling profit for regenerating graphite is approximately 7000 $ t−1. Given this, this work is anticipated to shed light on the closed-circuit recycling of spent graphite and offer significant strategies to repair graphite.