Affiliation: | 1. Institute of Science and Technology for New Energy, Xi'an Technological University, Xi'an, 710021 P. R. China;2. Department of Materials Science and Engineering, National University of Singapore, Singapore, 117573 Singapore Institute of High Performance Computing (IHPC), Agency for Science, Technology and Research (A*STAR), 1 Fusionopolis Way, #16-16 Connexis, Singapore, 138632 Republic of Singapore AVIC Xi'an Flight Automatic Control Research Institute, Shaanxi, 710065 China;3. State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an, 710072 China;4. Department of Materials Science and Engineering, National University of Singapore, Singapore, 117573 Singapore;5. Department of Materials Science and Engineering, National University of Singapore, Singapore, 117573 Singapore Institute of High Performance Computing (IHPC), Agency for Science, Technology and Research (A*STAR), 1 Fusionopolis Way, #16-16 Connexis, Singapore, 138632 Republic of Singapore |
Abstract: | Aqueous zinc ion batteries (ZIBs) exhibit great potential for next-generation energy storage devices. However, significant challenges exist, including the uncontrollable formation of Zn dendrite and side reactions during zinc stripping and plating. The mechanism of Zn dendrite nucleation has yet to be fully understood. In this work, the first principles simulations are used to investigate the Zn dendrite formation process. The unintentionally adsorbed O2− and OH− ions are the inducing factors for Zn dendrite nucleation and growth on the Zn (0001) plane due to significantly increased Zn diffusion barriers. A top-down method is demonstrated to suppress the dendrite using delaminated V2CTx to capture O2− and OH− ions thanks to reduced Zn diffusion barriers. The experimental results revealed significantly suppressed Zn dendrite nucleation and growth, resulting in a layer-by-layer deposit/stripping of Zn. Based on the electrochemical evaluations, the V2CTx-coated Zn composite delivers a high coulombic efficiency of 99.3% at 1.0 mAh cm−2. Furthermore, the full cell achieves excellent cyclic performance of 93.6% capacity retention after 2000 cycles at 1 A g−1. This strategy has broad scalability and can be widely applied in designing metallic anodes for rechargeable batteries. |