fig1

Figure 1. (A) Schematic diagram of the operational principle of SIBs; (B) Number of publications on SIB anodes in the past decade; (C) Different types of SIB anode materials. Quoted with permission from Huang et al.^[6]; (D) Reaction mechanism schematics of intercalation. Quoted with permission from Qiao et al.^[7]; (E) The mechanism of Na storage in HC. Quoted with permission from Chen et al.^[19]; (F and G) Reaction mechanism schematics of conversion and alloying. Quoted with permission from Qiao et al.^[7]. SIBs: Sodium-ion batteries; HC: hard carbon.