Soft carbon filled in expanded graphite layer pores for superior fast-charging lithium-ion batteries

Abstract

The slow kinetics and lithium deposition of graphite anode are considered the key limitations of fast-charging lithium-ion batteries. Expanded graphite has shown tremendous potential for the improvement of rate performance due to its massive active sites released and lifted lithium storage platform. However, the risk of structural collapse caused by fast charging will reduce the cycling life of the expanded graphite anode. Herein, this study designed a stable structure of expanded graphite by filling its layer pores with pitch-derived soft carbon (EGC). The honeycomb-like EGC is a great fast-charging candidate material with rich active sites, enlarged ion transport channels, and efficient ion transport interfaces. As the experimental and simulation results, the EGC electrode demonstrated significantly fast lithium-ions storage kinetics and durable long cycle life, compared to commercial fast-charging graphite anode. Notably, the EGC//LiNi0.8Co0.1Mn0.1O2 full cell delivered a superior fast-charging and stability performance (near 20 min charging for 80 % State of Charge). The simple multifunctional modification strategy for graphite anode in this work provides a new approach for superior fast-charging lithium-ion batteries.