Microwave-Irradiation-Assisted Combustion toward Modified Graphite as Lithium Ion Battery Anode.

A rapid method to high-yield synthesis of modified graphite by microwave irradiation of partially oxidized graphite (oxidized by HSO and KMnO) is reported. During the microwave irradiation, electrical arc induced flame combustion of MnO and vaporization and decomposition of HSO to form O and SO, which helped to decompose graphite within 30 s. The modified graphite boosts its ability to support the intercalation and diffusion of Li ions. As an anode material for lithium ion batteries, the modified graphite displays high reversible capacity of 373 mA·h/g, approaching the theoretical value of 372 mA·h/g. Long cycling performance of 410 charge-discharge cycles shows the capacity is retained at 370 mA·h/g, demonstrating superior stability. The improved cycling stability is attributed to the formation of a stable solid electrolyte interface film with the help of in situ formed S-based compounds on a graphite sheet. This work demonstrated a simple and effective method to alter carbon structures for improving energy storage ability.