Effects of Different Atmosphere on Electrochemical Performance of Hard Carbon Electrode in Sodium Ion Battery

Hard carbon is deemed to be a most promising anode materials for sodiumion batteries (SIBs), while, the issues of low capacity and low initial coulombic efficiency still exist limiting the development of SIBs. Although high temperature carbonization of biomass materials under nitrogen or argon atmosphere is a common method for preparation of hard carbon, there are few reports about the effects of different protective atmospheres on propriety of hard carbon. In this article, hornet's nest (HN) is used to prepare hard carbon under nitrogen and argon. At a suitable carbonization temperature (1200 degrees C and 1400 degrees C), the hard carbon under argon possesses lower specific surface area (25-50cm(-3)g(-1)), but higher initial coulomb efficiency (4-6%) and higher capacity retention (3-6%). Thus, it is inferred that highperformance hard carbon can be obtained under argon atmosphere. Our research about the effect of sintering atmosphere on material properties is expected to provide a reference for the synthetization of hard carbon by high temperature carbonization. [GRAPHICS] .