This book focuses on the development of high-performance carbon electrodes for sodium ion batteries (SIBs). By proposing folded-graphene as the high-density cathode with excellent rate capability, it provides insight into the interplay between oxygen functional groups and folded texture. It also highlights the superiority of ether electrolytes matching with carbon anodes, which are shown to deliver largely improved electrochemical performance. The achievements presented offer a valuable contribution to the carbon-based electrodes in SIBs.