Self-assembled homogeneous SiOC@C/graphene with three-dimensional lamellar structure enabling improved capacity and rate performances for lithium ion storage.

SiOC as an alternative silicon-based material possesses great potential in lithium ion batteries due to its high reversible capacity, tunable chemical component and various synthetic route. However, large-scale production of SiOC powders grinded from SiOC bulks is restricted in commercial application because of the poor electrical conductivity. Herein, three dimensional (3D) lamellar SiOC@C/rGO composite is fabricated through hydrothermal reaction and electrostatic self-assembly process, in which SiOC powders encapsulated by amorphous carbon layers are homogeneously dispersed in graphene sheets. C free nanoclusters in SiOC, carbon layers on SiOC surface and graphene supporters in the composite establish the multidimensional interconnected conductive architecture and possess favorable interfacial adhesion. Therefore, SiOC@C/rGO exhibits high specific capacity (676 mAh g−1 at 200 mA g−1) and remarkable rate capability (306.4 mAh g−1 at 4000 mA g−1). The full cell assembled with this anode and LiFePO 4 cathode also demonstrates stable voltage platform and good performance for 200 cycles. The excellent performance of SiOC@C/rGO profits from the synergistic effect of robust construction, multidimensional conductive architecture and chemical. The proposed strategy can also be developed to prepare other materials with graphene layer to enhance their electrical conductivity for commercial application. [Display omitted] • SiOC@C/rGO was fabricated through electrostatic self-assembly process. • Electrostatic repulsion between SiOC@C and GO was eliminated using a surfactant. • 3D conductive architecture was constructed by C free in SiOC, C layer and graphene. • Evenly dispersed SiOC and increased oxygen-rich SiOC units improved the capacity. • SiOC@C/rGO exhibits good electrochemical performance in both half and full-cell. [ABSTRACT FROM AUTHOR]