ABSTRACT

Rechargeable lithium-ion batteries (LIBs) have been extensively used in consumer electronics, power supply of electric vehicles, and the application to grid energy storage. 1 In commercial LIB systems, bulk graphite is the most commonly used anode material with its theoretical specific capacity of 372 mA h g−1. However, with the escalating demand for energy, searching new anode materials with higher capacity has become a critical issue nowadays. Among various carbonaceous materials, graphene-based materials have been viewed as a prospective alternative of anode material mainly due to their high reversible capacity (~1000 mA h g−1). 2–8 However, previous studies have shown that pristine monolayer graphene exhibits inferior Li capacity relative to bulk graphite. 9 , 10 Pan et al. 2 have investigated Li storage properties of disordered graphene nanosheets prepared via different reduction methods, reporting exceptionally high reversible capacities (794–1054 mA h g−1). They attributed the enhanced Li capacity to additional reversible storage sites such as edges and other defects due to the higher I D/I G ratio measured by Raman spectroscopy. 66Therefore, the existence of defects in graphene might be one of the main factors to enhance Li storage capacity.