fig2

Figure 2. (A) Schematic illustration of the heteroatom configuration screening strategy for the synthesis of PO-SC-S as an anode material of SIBs and its corresponding (B) Rate performance of full cells coupled with an O3- or P2/O3-type cathode with C-rates from 0.1 to 20 C. Quoted with permission from Xie et al.^[43]; (C) Synthesis scheme of NPUCS and NUCS and their corresponding (D) Rate capability. Quoted with permission from Wu et al.^[44]; (E) Schematic illustration of the synthesis process of UPCs; (F) Rate capability of UPC-6. Quoted with permission from Yan et al.^[47]. PO-SC-S: The pristine SC was co-doped with P/O and subsequently carbonized on two occasions at 800 °C; SIBs: sodium-ion batteries; NPUCS: N and P co-doped ultramicropores HC spheres; NUCS: N-doped ultra-micropores carbon spheres; UPCs: UPC-6: phosphorus-doped carbon with molar ratios n (PCl₃) : n (C₆H₁₂) = 6:1; SC: soft carbon.