Electrochemical Activation in Vanadium Oxide with Rich Oxygen Vacancies for High-Performance Aqueous Zinc-Ion Batteries

• Published in: ACS sustainable chemistry & engineering Vol. 12; no. 13; pp. 5117 - 5128
• Main Authors: Liang, Fangan, Chen, Min, Zhang, Shuchao, Zou, Zhengguang, Ge, Chuanqi, Jia, Shengkun, Le, Shangwang, Yu, Fagang, Nong, Jinxia
• Format: Journal Article
• Language: English
• Published: American Chemical Society 01.04.2024
• Subjects: activation; mechanism; aqueous zinc-ion batteries; V2O5; oxygen vacancies
• ISSN: 2168-0485; 2168-0485
• DOI: 10.1021/acssuschemeng.3c07655

Environmental concerns promote the development of sustainable energy storage devices. Resource-rich vanadium oxides with easily adjustable valence still exhibit unsatisfactory electrochemical performance stemming from poor electrical conductivity and friable structure as aqueous zinc-ion battery (AZIB) cathodes. Herein, vanadium oxide (VO-300) enriched with oxygen vacancies is acquired via a convenient solvothermal method in combination with subsequent heat treatment, which exhibits a remarkable rate performance of 411.98 mAh·g–1, and an excellent cycling life for 1500 cycles with 92.8% retention at 10 A·g–1. The enhanced electrochemical performances of VO-300 can be attributed to more oxygen vacancies, which provide more active sites for zinc-ion storage, expand layer spacing, and increase the conductivity of V2O5. More pivotal, the activation phenomenon is analyzed, and a two-carrier conversion insertion mechanism of H+ domination to Zn2+ domination is proposed. Based on this mechanism, the V2O5 is transformed into Zn x V2O5·nH2O as an active material for subsequent zinc-ion storage, leading to faster electrochemical kinetics. This work not only demonstrates the potential application of V2O5 as a zinc-ion cathode but also provides new insights into the zinc-ion storage mechanism.