Composite of nonexpansion reduced graphite oxide and carbon derived from pitch as anodes of Na-ion batteries with high coulombic efficiency

Graphite modified carbon materials have become one of the most promising candidate for sodium-ion battery anode materials. However, the low initial coulombic efficiency limits their further commercialization. In this work, composite of nonexpansion reduced graphite oxide and carbon derived from pitch (RGO/C800) has been prepared and characterized. The results show that there is no expansion of graphite oxide (GO) during the preparation, and it has not only a larger layer spacing, but also smaller specific surface area. Electrochemical tests show that RGO/C800 has a high initial discharge capacity of 268.4 mAh g−1, and a high initial coulombic efficiency of 79.2%.