Scalable synthesis and electrochemical performance of mesoporous graphene from calcium carbonate by magnesiothermic reaction

Abstract

A novel scalable synthetic method of mesoporous graphene has been developed using the compressed mixture of Mg and excess CaCO3 in a closed container. The generated solid oxide and unreacted CaCO3 could act as mesopore-forming agents, and the closed container could prevent the carbon dioxide from CaCO3 flow away. As a result, the graphenes with a large number of 2–30 ​nm mesopores and high utilization ratio of Mg achieved. The graphenes had high specific surface area and excellent electrochemical performance. In particular, the Mg utilization ratio was up to 53.3% in the preparation of graphene using 2:1 CaCO3/Mg at 700 ​°C, which is superior to previous researches. The obtained mesoporous graphene exhibited high specific surface area of 743.7 ​m2 ​g-1, large specific capacitance of 140 ​F ​g-1, and high capacitance retention rate of 64.3%.