Regulating the Thermodynamic Uniformity and Kinetic Diffusion of Zinc Anodes for Deep Cycling of Ah-Level Aqueous Zinc-Metal Batteries
Dongdong Wang, Rui Li, Xinyu Chen, Xiaohan Zhao, Hongxia Liu, Jie Zhang, Chuangwei Liu, Dan Luo, Jian Yang, Zhongwei Chen
Abstract
Zn metal anodes in mildly acidic electrolytes usually suffer from a series of problems, including parasitic dendrite growth and severe side reactions, significantly limiting the Zn utilization efficiency and cycling life. A deep understanding of the Zn stripping/plating process is essential to obtain high-efficiency and long-life Zn metal anodes. Here, the factors affecting the Zn stripping/plating process are revealed, suggesting that thermodynamic uniformity in bulk structures promotes an orderly Zn stripping process, and a fast kinetic diffusion rate on the Zn surface facilitates uniform Zn deposition. Then, a bulk and surface co-optimized strategy for stabilizing Zn metal anodes is proposed, which is confirmed to effectively suppress the Zn dendrite growth and side reactions. Thus, the modified Zn anodes display record-breaking cycling lives of 1200 and 200 h under ultrahigh Zn utilization efficiencies of 80 and 93.5%, respectively. More importantly, using this modified Zn metal anode enables us to realize Ah-level pouch cells for continuous cycles under harsh conditions.