Wang Mingshan, Zhang Jun, Zhang Linzi, Li Jiaqi, Wang Wenjie, Yang Zhenliang, Zhang Lei, Wang Yixian, Chen Junchen, Huang Yun, Mitlin David, Li Xing
School of New Energy and Materials, Southwest Petroleum University, Chengdu, Sichuan 610500, P. R. China.
Institute of Materials, China Academy of Engineering Physics, Mianyang, Sichuan 621907, P. R. China.
ACS Appl Mater Interfaces. 2020 Jul 15;12(28):31564-31574. doi: 10.1021/acsami.0c10183. Epub 2020 Jul 1.
A new approach is employed to boost the electrochemical kinetics and stability of vanadium oxygen hydrate (VOH, VO·HO) employed for aqueous zinc-ion battery (ZIB) cathodes. The methodology is based on electrically conductive polyaniline (PANI) intercalated-exfoliated VOH, achieved by preintercalation of an aniline monomer and its polymerization within the oxide interlayers. The resulting graphene-like PANI-VOH nanosheets possess a greatly boosted reaction-controlled contribution to the total charge storage capacity, resulting in more material undergoing the reversible V to V redox reaction. The PANI-VOH electrode obtains an impressive capacity of 323 mAh g at 1 A g, and state-of-the-art cycling stability at 80% capacity retention after 800 cycles. Because of the facile redox kinetics, the PANI-VOH ZIB obtains uniquely promising specific energy-specific power combinations: an energy of 216 Wh kg is achieved at 252 W kg, while 150 Wh kg is achieved at 3900 W kg. Electrochemical impedance spectroscopy (EIS) and galvanostatic intermittent titration technique (GITT) analyses indicate that with PANI-VOH nanosheets, there is a simultaneous decrease in the charge transfer resistance and a boost in the diffusion coefficient of Zn (by a factor of 10-100) the VOH baseline. The strategy of employing PANI for combined intercalation-exfoliation may provide a broadly applicable approach for improving the performance in a range of oxide-based energy storage materials.
一种新方法被用于提升用于水系锌离子电池（ZIB）阴极的钒氧水合物（VOH，VO·H₂O）的电化学动力学和稳定性。该方法基于导电聚苯胺（PANI）插层-剥离的VOH，通过苯胺单体的预插层及其在氧化物层间的聚合来实现。所得的类石墨烯PANI-VOH纳米片对总电荷存储容量具有极大增强的反应控制贡献，导致更多材料经历可逆的V⁴⁺到V⁵⁺氧化还原反应。PANI-VOH电极在1 A g时获得了令人印象深刻的323 mAh g的容量，并在800次循环后具有80%容量保持率的先进循环稳定性。由于氧化还原动力学的简便性，PANI-VOH ZIB获得了独特的、有前景的比能量-比功率组合：在252 W kg时实现了216 Wh kg的能量，而在3900 W kg时实现了150 Wh kg的能量。电化学阻抗谱（EIS）和恒电流间歇滴定技术（GITT）分析表明，对于PANI-VOH纳米片，电荷转移电阻同时降低，并且Zn²⁺的扩散系数相对于VOH基线提高了10 - 100倍。采用PANI进行联合插层-剥离的策略可能为提高一系列氧化物基储能材料的性能提供一种广泛适用的方法。
