Complexing agent engineered strategy for anchoring SnO2 nanoparticles on sulfur/nitrogen co-doped graphene for superior lithium and sodium ion storage

An effective strategy is proposed and developed to prepare sulfur/nitrogen co-doped graphene/SnO2 composite (denoted SNGS). The key point of this strategy is the choice of heteroatom-containing organic compounds, 5, 10, 15, 20-tetra-(4-sulfonato phenyl) porphyrin (TSPP), which can act as both the multi-heteroatom codoped source and the complexing agent. After the calcination, the doped sulfur/nitrogen atoms could effectively pin SnO2 nanocrystals on graphene sheets due to the existence of the binding effect. As a result, the unique feature as well as the synergetic effect between sulfur/nitrogen co-doped graphene and SnO2 nanocrystals endows the composite materials with good electrochemical performances as anode materials for lithium ion batteries (LIBs) and sodium ion batteries (SIBs), including high initial discharge capacity (1089 mAh g(-1) at 50 mA g(-1) for LIBs and 673.8 mAh g(-1) at 25 mA g(-1) for SIBs) and reversible capacity (924.4 mAh g(-1) after 150 cycles for LIBs and 264.9 mAh g(-1) after 100 cycles for SIBs). The strategy derived from heteroatom-containing organic compounds might open new avenues for the design of high-performance doped graphene/metal oxide anode materials.