Wei Pengcheng, Zhu Jinliang, Qiu Yuyan, Wang Guifang, Xu Xingtao, Ma Shaojian, Shen Pei Kang, Wu Xing-Long, Yamauchi Yusuke
Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials, School of Resources, Environment and Materials, Collaborative Innovation Center of Sustainable Energy Materials, Guangxi University Nanning 530004 P. R. China
International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science 1-1 Namiki Tsukuba Ibaraki 305-0044 Japan
Chem Sci. 2021 Oct 27;12(45):15054-15060. doi: 10.1039/d1sc04163k. eCollection 2021 Nov 24.
Herein, a chemical-vapor deposition-like strategy was developed for the synthesis of versatile core-shell transition metal sulfide (TMS)@carbon nanowires with chemically-bonded heterostructures and significantly improved electrochemical performance. The morphological evolution observations revealed the simultaneous growth of TMS nanowires and their bonding with an ultrathin carbon layer. The resulting core-shell heterostructured nanowires possessed notable advantages, including fast ion/electron diffusion rates, improved conductivity, and chemical/mechanical stability, thereby leading to remarkable reversible capacity, rate capability, and cycling stability for Na-ion storage applications. The transmission electron microscopy and X-ray diffraction studies for FeS@C demonstrated the crystalline phase evolution between hexagonal and tetragonal FeS species during the electrochemical charging/discharging process, clearly indicating the excellent Na-ion storage performance of FeS@C nanowires. This work provides a new methodology for achieving 1D core-shell nanoarchitectures, while elucidating the electrochemical reaction mechanism underlying Na-ion storage in TMS materials.
在此，开发了一种类似化学气相沉积的策略，用于合成具有化学键合异质结构且电化学性能显著提高的多功能核壳过渡金属硫化物（TMS）@碳纳米线。形态演变观察揭示了TMS纳米线的同时生长及其与超薄碳层的结合。所得的核壳异质结构纳米线具有显著优势，包括快速的离子/电子扩散速率、提高的导电性以及化学/机械稳定性，从而在钠离子存储应用中实现了显著的可逆容量、倍率性能和循环稳定性。对FeS@C进行的透射电子显微镜和X射线衍射研究表明，在电化学充放电过程中，六方和四方FeS物种之间发生了晶相演变，清楚地表明了FeS@C纳米线优异的钠离子存储性能。这项工作为实现一维核壳纳米结构提供了一种新方法，同时阐明了TMS材料中钠离子存储的电化学反应机制。
