Zong Quan, Du Wei, Liu Chaofeng, Yang Hui, Zhang Qilong, Zhou Zheng, Atif Muhammad, Alsalhi Mohamad, Cao Guozhong
Department of Materials Science and Engineering, University of Washington, Seattle, WA, 98195, USA.
School of Materials Science and Engineering, State Key Lab Silicon Mat, Zhejiang University, Hangzhou, 310027, People's Republic of China.
Nanomicro Lett. 2021 Apr 30;13(1):116. doi: 10.1007/s40820-021-00641-3.
Ammonium vanadate with bronze structure (NHVO) is a promising cathode material for zinc-ion batteries due to its high specific capacity and low cost. However, the extraction of [Formula: see text] at a high voltage during charge/discharge processes leads to irreversible reaction and structure degradation. In this work, partial [Formula: see text] ions were pre-removed from NHVO through heat treatment; NHVO nanosheets were directly grown on carbon cloth through hydrothermal method. Deficient NHVO (denoted as NVO), with enlarged interlayer spacing, facilitated fast zinc ions transport and high storage capacity and ensured the highly reversible electrochemical reaction and the good stability of layered structure. The NVO nanosheets delivered a high specific capacity of 457 mAh g at a current density of 100 mA g and a capacity retention of 81% over 1000 cycles at 2 A g. The initial Coulombic efficiency of NVO could reach up to 97% compared to 85% of NHVO and maintain almost 100% during cycling, indicating the high reaction reversibility in NVO electrode.
具有青铜结构的钒酸铵（NHVO）因其高比容量和低成本，是一种很有前景的锌离子电池阴极材料。然而，在充放电过程中，在高电压下提取[化学式：见原文]会导致不可逆反应和结构退化。在这项工作中，通过热处理从NHVO中预先去除部分[化学式：见原文]离子；通过水热法将NHVO纳米片直接生长在碳布上。层间距增大的缺陷型NHVO（记为NVO）促进了锌离子的快速传输和高存储容量，并确保了高度可逆的电化学反应和层状结构的良好稳定性。在100 mA g的电流密度下，NVO纳米片的比容量高达457 mAh g，在2 A g下1000次循环后的容量保持率为81%。与NHVO的85%相比，NVO的初始库仑效率可达97%，并且在循环过程中几乎保持100%，这表明NVO电极具有高反应可逆性。
