A High‐Energy Tellurium Redox‐Amphoteric Conversion Cathode Chemistry for Aqueous Zinc Batteries
Jingwei Du, Yirong Zhao, Xingyuan Chu, Gang Wang, Christof Neumann, Hao Xu, Xiaodong Li, Markus Löffler, Qiongqiong Lu, Jiaxu Zhang, Dongqi Li, Jianxin Zou, Daria Mikhailova, Andrey Turchanin, Xinliang Feng, Minghao Yu
Abstract
Abstract Rechargeable aqueous zinc batteries are potential candidates for sustainable energy storage systems at a grid scale, owing to their high safety and low cost. However, the existing cathode chemistries exhibit restricted energy density, which hinders their extensive applications. Here, a tellurium redox‐amphoteric conversion cathode chemistry is presented for aqueous zinc batteries, which delivers a specific capacity of 1223.9 mAh g Te −1 and a high energy density of 1028.0 Wh kg Te −1 . A highly concentrated electrolyte (30 mol kg −1 ZnCl 2 ) is revealed crucial for initiating the Te redox‐amphoteric conversion as it suppresses the H 2 O reactivity and inhibits undesirable hydrolysis of the Te 4+ product. By carrying out multiple operando/ex situ characterizations, the reversible six‐electron Te 2− /Te 0 /Te 4+ conversion with TeCl 4 is identified as the fully charged product and ZnTe as the fully discharged product. This finding not only enriches the conversion‐type battery chemistries but also establishes a critical step in exploring redox‐amphoteric materials for aqueous zinc batteries and beyond.