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论文类型：期刊论文

发表时间：2018-09-01

发表刊物：FUEL PROCESSING TECHNOLOGY

收录刊物：SCIE

卷号：178

页面范围：35-40

ISSN号：0378-3820

关键字：Coal liquefaction residue; Hard carbon; Graphene; Sodium ion battery

摘要：A graphene coated coal liquefaction residue (CLR) derived hard carbon (HC@G) composite anode for sodium ion batteries was prepared by thermal annealing the mixture of the chemically modified hard carbon with graphene oxide. The irregular shaped hard carbon particles were coated uniformly by wrinkled graphene sheets. Both HC and HC@G possess large inter-layer spacing and poor porosity, but a richer pore structure that facilitating ion transport was generated after graphene coating. Because poor conductive hard carbon particles are bridged by graphene sheets, a better conductivity of HC@G is detected by voltammetry test and the EIS analysis. Graphene coating contributes little to the sodium storage capacity. However, HC@G exhibits a much better rate performance and a dramatic improvement of cycling capability with the capacity retention 83% after 2000 cycles at a high current density of 2 A.g(-1). The impressing rate and cycle performances of HC@G anode are attributed to the hierarchical structure with rich ion diffusion channels and extensive electronic conduction path.