fig4

Figure 4. (A) Schematic diagram of the PN-CHoNS synthesis; (B and C) the SEM images of PN-CHoNS HSCs; (D) The charge-discharge profiles of ZHSC; (E) In-situ Raman spectra of PN-CHoNS cathode during charging/discharging process. Reproduced with permission from Ref.^[77]. Copyright 2024, Elsevier. HSCs: Hybrid supercapacitors; PN-CHoNS: P/N dual-doped hollow carbon spheres; SEM: scanning electron microscopy; ZHSC: Zinc-ion hybrid supercapacitors.