1. State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan 430081, China
2. Key Laboratory of Hubei Province for Coal Conversion and New Carbon Materials, Wuhan University of Science and Technology, Wuhan 430081, China
Carbon materials are unique due to their wide variety and special structure, possessing good electrical and thermal conductivity, chemical stability and excellent mechanical properties, and can be used as conductive agents, heat exchangers, reinforcing materials, etc., thereby playing a pivotal and irreplaceable role in the traditional materials, functional materials, high and new technology, new energy and ecological environment and other fields. However, carbon materials usually exist a certain number of pores, cracks and structural defects, which directly affect their physical properties and practical applications. Densification is a commonly used means to improve the performance of carbon materials by effectively reducing the internal pores and cracks, increasing the bulk density and compact degree, and improving the microcrystalline structure and orientation, so as to result in a substantial improvement in their mechanical properties, thermal conductivity and electrical properties. The classification, properties and applications of carbon materials are firstly introduced in this paper, then the crystal structure, theoretical density and internal pores formation and category of carbon materials are reviewed, and the purpose and principle of carbon material densification are emphasized. Different methods and techniques of carbon material densification are summarized systematically, including hot-mold sintering densification,thermal shrinkage densification, liquid impregnation densification and gas-phase infiltration/deposition densification. Meanwhile, the emerging applications of densified carbon materials are updated, including highperformance carbon fibers and their composites, as well as carbon-based energy storage. Finally, the development trend and application prospect of carbon material densification are forecasted.