摘要: The impurities and structural cracks within spent graphite (SG) in lithium-ion battery anodes hamper lithium-ion intercalation and extraction after successive charge-discharge operations, thereby yielding poor lithium storage behavior. Herein, low-viscosity natural DES (NDES) composed of citric acid (CA) and betaine hydrochloride (BeCl) was employed to remove the organic impurities in SG via a one-step benign process involving hydrogen bonds and electrostatic interactions at mild conditions of 80 ℃ for only 30 min. After NDES leaching under optimal conditions (molar ratio of citric acid to betaine hydrochloride = 3:1, 80 ℃, 30 min), the as-obtained sample (denoted as BG-3) exhibited an extremely clean surface, moderately enlarged interlayer distance, and more structural defects at the edge of graphite lamellae. These features facilitated lithium-ion intercalation and withdrawal, bestowing BG-3 with remarkable activity in LIB recycling. For instance, BG-3 delivered a capacity of 438.6 mAh g^-1 at a current density of 0.1 A g^-1. Its capacity retention reached 97.9%, accompanied by a Coulombic efficiency of 99.1%, upon completing 100 cycles. Molecular dynamics (MD) simulation was employed to illuminate the regeneration mechanism for anode graphite from theoretical perspective. It revealed that NDES exhibits lower binding energy with all contaminants compared to graphite, which is favorable for NDES to eliminate impurities from graphite surfaces. This study unveils a method of recycling SG from retired LIBs by a short eco-friendly process, providing a competitive blueprint to address the shortage of battery-grade anode graphite and achieve carbon neutrality.