Heteroatom doping-induced formation of closed pores for high-performance sodium storage hard carbon anodes

Abstract

A resin-based hard carbon with rich closed pores is prepared by the in situ reconstruction of cavities formed after heteroatoms evaporated during a high-temperature carbonization process. Various characterization results confirm that rich defect sites and micropores and enlarged layer spacing in hard carbon promote Na⁺ transport and facilitate high-performance Na⁺ storage.