Zhang Yan, Deng Shengjue, Luo Mi, Pan Guoxiang, Zeng Yinxiang, Lu Xihong, Ai Changzhi, Liu Qi, Xiong Qinqin, Wang Xiuli, Xia Xinhui, Tu Jiangping
State Key Laboratory of Silicon Materials, Key Laboratory of Advanced Materials and Applications for Batteries of Zhejiang Province, and Department of Materials Science and Engineering, Zhejiang University, Hangzhou, 310027, P. R. China.
Department of Materials Chemistry, Huzhou University, Huzhou, 313000, China.
Small. 2019 Nov;15(47):e1905452. doi: 10.1002/smll.201905452. Epub 2019 Oct 14.
Defect engineering (doping and vacancy) has emerged as a positive strategy to boost the intrinsic electrochemical reactivity and structural stability of MnO -based cathodes of rechargeable aqueous zinc ion batteries (RAZIBs). Currently, there is no report on the nonmetal element doped MnO cathode with concomitant oxygen vacancies, because of its low thermal stability with easy phase transformation from MnO to Mn O (≥300 °C). Herein, for the first time, novel N-doped MnO (N-MnO ) branch arrays with abundant oxygen vacancies fabricated by a facile low-temperature (200 °C) NH treatment technology are reported. Meanwhile, to further enhance the high-rate capability, highly conductive TiC/C nanorods are used as the core support for a N-MnO branch, forming high-quality N-MnO @TiC/C core/branch arrays. The introduced N dopants and oxygen vacancies in MnO are demonstrated by synchrotron radiation technology. By virtue of an integrated conductive framework, enhanced electron density, and increased surface capacitive contribution, the designed N-MnO @TiC/C arrays are endowed with faster reaction kinetics, higher capacity (285 mAh g at 0.2 A g ) and better long-term cycles (85.7% retention after 1000 cycles at 1 A g ) than other MnO -based counterparts (55.6%). The low-temperature defect engineering sheds light on construction of advanced cathodes for aqueous RAZIBs.
缺陷工程（掺杂和空位）已成为一种积极的策略，用于提高可充电水系锌离子电池（RAZIBs）MnO基正极的本征电化学反应活性和结构稳定性。目前，尚无关于伴随氧空位的非金属元素掺杂MnO正极的报道，因为其热稳定性低，在≥300°C时容易从MnO相转变为MnO 。在此，首次报道了通过简便的低温（200°C）NH处理技术制备的具有丰富氧空位的新型N掺杂MnO （N-MnO ）分支阵列。同时，为了进一步提高高倍率性能，将高导电性的TiC/C纳米棒用作N-MnO 分支的核心支撑，形成高质量的N-MnO @TiC/C核/分支阵列。通过同步辐射技术证明了MnO中引入的N掺杂剂和氧空位。借助集成的导电框架、增强的电子密度和增加的表面电容贡献，所设计的N-MnO @TiC/C阵列具有比其他MnO基对应物更快的反应动力学、更高的容量（在0.2 A g 时为285 mAh g ）和更好的长期循环性能（在1 A g 下1000次循环后保持率为85.7%，而其他MnO基对应物为55.6%）。低温缺陷工程为水系RAZIBs先进正极的构建提供了思路。
