Gold‐Nanolayer‐Derived Zincophilicity Suppressing Metallic Zinc Dendrites and Its Efficacy in Improving Electrochemical Stability of Aqueous Zinc‐Ion Batteries

• Published in: Advanced materials (Weinheim) Vol. 36; no. 1; pp. e2308592 - n/a
• Main Authors: Kim, Hee Jae, Kim, Sun, Kim, Suhwan, Kim, Sungkyu, Heo, Kwang, Lim, Jae‐Hong, Yashiro, Hitoshi, Shin, Hyeon‐Ji, Jung, Hun‐Gi, Lee, Yong Min, Myung, Seung‐Taek
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.01.2024
• Subjects: dendrite suppression; Electric fields; Electrochemical analysis; Electrode materials; Electrodeposition; Electrodes; Gold; Gold coatings; gold nanolayer coating; Synchrotrons; Zinc; zincophilic surface; zinc‐gold alloy; zinc‐ion battery; zinc-gold alloy; zinc-ion battery; dendrite suppression; gold nanolayer coating; zincophilic surface
• DOI: 10.1002/adma.202308592
• ISSN: 0935-9648

Herein, an Au‐coating layer adjusted on the surface of a Zn metal electrode that effectively suppresses the dendrite growth as well as the mechanisms underlying the dendrite suppression as a result of the zincophilic character of Au is introduced. For the Au‐coated Zn metal symmetric cell, uniform deposition of Zn‐derived compounds was revealed by operando synchrotron tomography. Microscopic studies demonstrate that the Au‐coating layer is induced to form a new Zn–Au alloy during the initial Zn deposition, resulting in stabilized long‐term stripping/plating of Zn via the ‘embracing effect’ that intimately accommodates Zn deposition for further cycles. This property supports the successful operation of symmetrical cells up to 50 mA cm−2. According to Zn electrodeposition simulation, it is verified that the suppression of dendrite growth is responsible for the electro‐conducting Au nanolayer that uniformly distributes the electric field and protects the Zn electrode from corrosion, ultimately promoting uniform Zn growth. The compatibility of the Au‐coating layer for full cell configuration is verified using NaV3O8 as a cathode material over 1 000 cycles. This finding provides a new pathway for the enhancement of the electrochemical performance of ZIBs by suppressing the dendritic growth of Zn by means of a zincophilic Au nanolayer. From the initial Zn deposition, a Zn‐Au alloy grows from the Au‐coating layer. This further results in smooth Zn deposition, which stabilizes long‐term Zn stripping/plating without Zn dendrite via the ‘embracing effect’.