Construction of three-dimensional carbon framework-loaded silicon nanoparticles anchored by carbon film for high-performance lithium-ion battery anode materials

Si materials are widely considered to be the next-generation anode to replace the current commercial graphite-based anode due to its high energy density. However, the large volume variation of silicon during (de)lithiation process leads to rapid capacity decay, hindering its commercial application. Although the various hollow structure designs of Si nanomaterials have improved their cycling stability in the laboratory, the high-pressure calendering process in the current industrial electrode preparation process might collapse the hollow structure and weaken the structural advantages of hollow silicon anode materials. In this work, a silicon carbon composite material (Si@3DC) in which Si nanoparticles were anchored on a three-dimensional carbon framework through carbon films was prepared by a simple proton exchange method. The three-dimensional carbon framework with multiple hierarchical pores of Si@3DC was compatible with the high-pressure calendering process, but also could provide expansion space for Si nanoparticles during the lithiation process, and ensure good electronic and ionic conductivity. The carbon film on the surface of Si nanoparticles promoted the formation of stable solid electrolyte interphase (SEI) films, ensuring the good cycle stability of Si@3DC.