Zhang Xiaotan, Li Jiangxu, Liu Yanfen, Lu Bingan, Liang Shuquan, Zhou Jiang
School of Materials Science and Engineering, Central South University, Changsha, 410083, Hunan, PR China.
Department of Applied Chemistry, University of Science and Technology of China, Hefei, 230026, Anhui, PR China.
Nat Commun. 2024 Mar 28;15(1):2735. doi: 10.1038/s41467-024-47101-1.
The optimization of crystalline orientation of a Zn metal substrate to expose more Zn(0002) planes has been recognized as an effective strategy in pursuit of highly reversible Zn metal anodes. However, the lattice mismatch between substrate and overgrowth crystals has hampered the epitaxial sustainability of Zn metal. Herein, we discover that the presence of crystal grains deviating from [0001] orientation within a Zn(0002) metal anode leads to the failure of epitaxial mechanism. The electrodeposited [0001]-uniaxial oriented Zn metal anodes with a single (0002) texture fundamentally eliminate the lattice mismatch and achieve ultra-sustainable homoepitaxial growth. Using high-angle angular dark-filed scanning transmission electron microscopy, we elucidate the homoepitaxial growth of the deposited Zn following the "ABABAB" arrangement on the Zn(0002) metal from an atomic-level perspective. Such consistently epitaxial behavior of Zn metal retards dendrite formation and enables improved cycling, even in Zn||NHVO pouch cells, with a high capacity of 220 mAh g for over 450 cycles. The insights gained from this work on the [0001]-oriented Zn metal anode and its persistently homoepitaxial mechanism pave the way for other metal electrodes with high reversibility.
优化锌金属基底的晶体取向以暴露出更多的Zn(0002)平面，已被认为是追求高可逆性锌金属负极的有效策略。然而，基底与外延生长晶体之间的晶格失配阻碍了锌金属的外延可持续性。在此，我们发现，在Zn(0002)金属负极中存在偏离[0001]取向的晶粒会导致外延机制失效。具有单一(0002)织构的电沉积[0001]单轴取向锌金属负极从根本上消除了晶格失配，并实现了超可持续的同质外延生长。利用高角度环形暗场扫描透射电子显微镜，我们从原子层面阐明了沉积的锌在Zn(0002)金属上按照“ABABAB”排列进行同质外延生长的过程。锌金属这种持续的外延行为抑制了枝晶形成，并实现了更好的循环性能，即使在Zn||NHVO软包电池中，在超过450次循环中也能保持220 mAh g的高容量。这项工作中关于[0001]取向锌金属负极及其持续同质外延机制的见解为其他具有高可逆性的金属电极铺平了道路。
