Zinc‐Ion Anchor Induced Highly Reversible Zn Anodes for High Performance Zn‐Ion Batteries
Shuang Zhou, Xinyu Meng, Yining Chen, Jianwen Li, Shangyong Lin, Chao Han, Xiaobo Ji, Zhi Chang, Anqiang Pan
Abstract
Abstract Unstable Zn interface with serious detrimental parasitic side‐reactions and uncontrollable Zn dendrites severely plagues the practical application of aqueous zinc‐ion batteries. The interface stability was closely related to the electrolyte configuration and Zn 2+ depositional behavior. In this work, a unique Zn‐ion anchoring strategy is originally proposed to manipulate the coordination structure of solvated Zn‐ions and guide the Zn‐ion depositional behavior. Specifically, the amphoteric charged ion additives (denoted as DM), which act as zinc‐ion anchors, can tightly absorb on the Zn surface to guide the uniform zinc‐ion distribution by using its positively charged −NR 4 + groups. While the negatively charged −SO 3 − groups of DM on the other hand, reduces the active water molecules within solvation sheaths of Zn‐ions. Benefiting from the special synergistic effect, Zn metal exhibits highly ordered and compact (002) Zn deposition and negligible side‐reactions. As a result, the advanced Zn||Zn symmetric cell delivers extraordinarily 7000 hours long lifespan (0.25 mA cm −2 , 0.25 mAh cm −2 ). Additionally, based on this strategy, the NH 4 V 4 O 10 ||Zn pouch‐cell with low negative/positive capacity ratio (N/P ratio=2.98) maintains 80.4 % capacity retention for 180 cycles. A more practical 4 cm*4 cm sized pouch‐cell could be steadily cycled in a high output capacity of 37.0 mAh over 50 cycles.