fig4

Figure 4. XPS spectra of (A) Mg 2s, (B) Cl 2p, and (C) EDS spectra for expanded VS₂ electrodes. Reproduced with permission^[78]. Copyright 2019, Wiley-VCH GmbH. (D) Charge-discharge curves (A = Li, Na, K) and (E) cycling performance of A-V₃O₈ (A = Li, Na, K) at 100 mA g^-1, and (F) spacing change of NaV₃O₈ at different charge-discharge stages. Reproduced with permission^[84]. Copyright 2019, Elsevier. (G) Formation of CaV₆O₁₆·2.8H₂O and (H) Ca-storage in CaV₆O₁₆·2.8H₂O. Reproduced with permission^[178]. Copyright 2022, Wiley-VCH GmbH. (I) Cycling performance of Zr-NH₄V₄O₁₀ at 0.2 A g^-1. Reproduced with permission^[92]. Copyright 2022, Elsevier.