Construction of oxygen defects in V2O5 for improved performance in Zn-ion battery and sea water desalination

Abstract

Zn-ion battery has received researcher's interests for nonflammable and clean aqueous electrolyte, cheap and harmless Zn anode. Cathode material plays a vital role in Zn-ion battery, which can influence its performance directly. Because of suitable layer spacing, V2O5 has been considered as a potential cathode material for Zn-ion battery. But its prospect in Zn-ion battery is hindered by low conductivity. To resolve this problem, oxygen defect rich V2O5 (Od-V2O5) is synthesized. It possesses perfect stability when served as cathode material in Zn-ion battery. The specific capacity achieves 425 mAh·g−1 at 0.1 ​A ​g−1. Oxygen defect also prompts the separation of electron-hole pairs and makes more electrons participate in photothermal conversion, which boosts photo energy transforms to thermal energy. For Od-V2O5, it shows high photothermal effect efficiency. With Od-V2O5, photothermal membrane is fabricated with electrospinning technique and applied for solar steam generation sea water desalination. Evaporation rate of the membrane reaches 1.29 ​kg ​m−2 ​h−1 with energy conversion efficiency 88.1% under 1 sun irradiation. The energy efficiency keeps stable after continuous evaporation. In evaporated water, the concentration of Na+, K+ Ca2+ and Mg2+ can satisfy the standard of human drinking water. We expect Od-V2O5 has a bright prospect in Zn-ion battery and sea water desalination.