Kilogram-Scale Production of Ultrafast-Charging Micro-Expanded Graphite Anode toward High-Power and Long-Life Ah-Level Pouch Batteries.

Abstract

The exponential growth of electric vehicle industry necessitates to rapidly develop fast-charging technology for lithium-ion batteries. However, the mainstream graphite anode encounters significant challenges in fast-charging scenarios, including capacity decay and shortened lifespan caused by the sluggish lithiation kinetics and unstable solid electrolyte interphase. Herein, the kilogram-level scalable production of ultrafast-charging anode (C@MEG) consisting of micro-expanded graphite coated by an ultrathin disordered carbon layer (5 nm) is reported, which simultaneously compensates for the conventional limitation of internal lithium diffusion kinetics and reconfigures the external electrode-electrolyte interface. This uniqueness endows rapid surface-to-bulk lithium transport, with minimized electrode polarization, enhanced pseudocapacitive behavior, and reduced interface impedance. At an ultrafast-charging rate of 10 C, this Li||C@MEG cell exhibits an ultrahigh capacity of 157 mAh g-1, superior to pristine graphite (71 mAh g-1) and previously reported graphite anodes. Moreover, this assembled 1 Ah-level C@MEG||LiCoO2 pouch battery delivers remarkable fast-charging cyclability, showcasing 92% capacity retention after 1000 cycles under 3 A, together with high power density around 1500 W kg-1 under 10 A, corresponding to a short charging time of only 4.2 min, demonstrative of applicability. This work presents a practical scalable fast-charging anode toward high-energy, high-power and long-life batteries.