Why does the capacity of vanadium selenide based aqueous zinc ion batteries continue to increase during long cycles?

Shinan Cai; Yuanke Wu; Hao Chen; Yandong Ma; TongXin Fan; Maowen Xu; Shu-Juan Bao

doi:10.1016/j.jcis.2022.01.160

Why does the capacity of vanadium selenide based aqueous zinc ion batteries continue to increase during long cycles?

J Colloid Interface Sci. 2022 Jun:615:30-37. doi: 10.1016/j.jcis.2022.01.160. Epub 2022 Jan 29.

Authors

Shinan Cai¹, Yuanke Wu¹, Hao Chen¹, Yandong Ma¹, TongXin Fan¹, Maowen Xu², Shu-Juan Bao³

Affiliations

¹ Key Laboratory of Luminescence Analysis and Molecular Sensing, Ministry of Education, School of Materials and Energy, Southwest University, Chongqing 400715, PR China.
² Key Laboratory of Luminescence Analysis and Molecular Sensing, Ministry of Education, School of Materials and Energy, Southwest University, Chongqing 400715, PR China. Electronic address: xumaowen@swu.edu.cn.
³ Key Laboratory of Luminescence Analysis and Molecular Sensing, Ministry of Education, School of Materials and Energy, Southwest University, Chongqing 400715, PR China. Electronic address: baoshj@swu.edu.cn.

PMID: 35124504
DOI: 10.1016/j.jcis.2022.01.160

Abstract

At present, rechargeable aqueous zinc ion batteries (RZIBs) have become a rising star and highly sought after in the field of new energy. While vanadium-based RZIBs often exhibit an anomaly of increased long-cycle capacity, which has not been explored in depth. Nevertheless, it is critical to understand this phenomenon to develop high-performance RZIBs. Therefore, this study investigated the growth mechanism of VSe₂-based RZIBs using VSe₂/MXene as the cathode material via in-situ and ex-situ characterization techniques and electrochemical measurements. Experimental results indicated that with the interaction/extraction of Zn²⁺/H⁺ in the host material during cycling, an obvious oxidation reaction occurs at high voltage, and the formed vanadium oxide further reacts with Zn²⁺ from the electrolyte. As a result, Zn_0.25V₂O₅·H₂O is continuously produced and accumulated, contributing to the increasing capacity of the prepared RZIBs.

Keywords: Aqueous zinc-ion batteries; Energy storage mechanism; Increased long-cycle capacity; VSe(2)/MXene; Zn(0.25)V(2)O(5)·H(2)O.