Graphene-Based Nanomaterials for Sodium-Ion Batteries

Sodium-ion batteries (SIBs) are considered as promising candidates for large-scale energy storage systems due to the wide availability and low cost of raw sodium resources. However, the heavier mass and larger radius of Na+ inevitably result in lower electrochemical kinetics and larger volume expansion of active materials than that of lighter and smaller Li+. To solve these problems, rational electrode design by integrating nanomaterials with graphene is an effective approach. In this review, the authors mainly focus on recent progress of graphene-based nanomaterials for SIBs, including their design principle, preparation, characterization, and electrochemical performance. The important roles of graphene in graphene-based inorganic and organic electrode materials are discussed in depth. In such composites, graphene can effectively enhance the electrical conductivity and mitigate volume change due to the robust and highly conductive networks formed by graphene. Moreover, the nanosized materials can enhance the reaction kinetics. Future research should focus on revealing the interaction mechanism between graphene and active materials, and improving the whole energy/power density, cycling stability, and the initial Coulombic efficiency of graphene-based nanomaterials via elaborate design.