image: Bare Zn suffers from both dendrite growth and corrosion in a; Zinc anode with zincophilic layer suppresses dendrite growth but still suffers from corrosion in b; Zinc anode with artificial SEI layer suppresses corrosion but still suffers from dendrite growth in c. Zinc anode with buried interface suppresses both dendrite growth and corrosion in d.
Credit: ©Science China Press
The issues of dendrite growth and corrosion have hindered the widespread application of aqueous zinc-ion batteries. Dendrites are finger-like structures that can form on the anode during charging, leading to short circuits and battery failure. Corrosion weakens the anode material over time, reducing battery life.
To tackle these problems, the research team from the School of Metallurgy and Environment at Central South University, together with their collaborators, has proposed a buried interface engineering strategy. This involves embedding a zincophilic Sn layer within a corrosion-resistant ZnS layer. The Sn layer, with its strong adsorption energy for Zn atoms, accelerates the nucleation of Zn atoms and promotes smooth deposition. Meanwhile, the outer ZnS layer acts as a protective barrier, shielding the newly deposited zinc from corrosion by the electrolyte.
The research demonstrates the effectiveness of the SZS coating through rigorous testing. In the symmetric cell test, the SZS@Zn anode showed stable cycling for over 280 hours at a high current of 10 mA cm-2 and a high areal capacity of 10 mAh cm-2, compared to bare zinc, which lasted only 41 hours. Furthermore, SZS@Zn//MnO2 full cells achieved enhanced long-term cycling stability of 63.6% for 1000 cycles at a high rate of 10C, significantly outperforming bare zinc, which maintained only 47.2% stability.
"By observing and analyzing the morphology and composition of the anode before and after cycling, as well as the deposition process, we found that the SZS-coated zinc anode showed uniform deposition and less corrosion," said Wen Qing, a doctoral student and co-first author of the study.
The results of this study are of great significance to the field of energy storage technology. The buried interface engineering approach provides new insights into the rational design of stable interfaces for metal anodes and offers a promising solution to the challenges faced by aqueous zinc-ion batteries. With further research and development, this strategy could create more efficient, reliable, and durable batteries for a wide range of applications.
This work was supported by funding agencies, including the National Natural Science Foundation of China, the Innovation Program of Hunan Province, and the Science and Technology Program of Changsha City.