Guo Changyuan, Liu Ziang, Han Kang, Zhang Liuyang, Ding Xiaoling, Wang Xuanpeng, Mai Liqiang
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, School of Materials Science and Engineering, Wuhan University of Technology, Wuhan, 430070, P. R. China.
Department of Physical Science & Technology, School of Science, Wuhan University of Technology, Wuhan, 430070, P. R. China.
Small. 2022 Mar;18(12):e2107365. doi: 10.1002/smll.202107365. Epub 2022 Feb 1.
The further demand for electric vehicles and smart grids prompts that the comprehensive function of lithium-ion batteries (LIBs) has been improved greatly. However, due to sluggish Li diffusion rate, thermal runway and volume expansion, the commercial graphite as an important part of LIBs is not suitable for fast-charging. Herein, nano-sized Nb W O blocks are effectively synthesized as a fast-charge anode material. The nano-sized structure provides shorter Li diffusion pathway in the solid phase than micro-sized materials by several orders of magnitude, corresponding to accelerating the Li diffusion rate, which is beneficial for fast-charge characteristics. Consequently, Nb W O displays excellent long-term cycling life (135 mAh g over 1000 cycles at 10 C) and rate capability at ultra-high current density (≈103.9 mAh g , 100 C) in half-cells. In situ X-ray diffraction and Raman combined with scanning electron microscopy clearly confirms the stability of crystal and microstructure. Furthermore, the fabricated Nb W O ||LiFePO full cells exhibit a remarkable power density and demonstrate a reversible specific capacity. The pouch cell delivers long cycling life (the capacity retention is as high as 96.6% at 10 C after 5000 cycles) and high-safety performance. Therefore, nano-sized Nb W O could be recognized as a promising fast-charge anode toward next-generation practical LIBs.
对电动汽车和智能电网的进一步需求促使锂离子电池（LIBs）的综合性能有了很大提升。然而，由于锂扩散速率缓慢、热失控和体积膨胀，作为LIBs重要组成部分的商用石墨并不适合快速充电。在此，有效地合成了纳米尺寸的铌钨氧化物块体作为快速充电阳极材料。与微米尺寸的材料相比，纳米尺寸结构在固相中提供了短几个数量级的锂扩散路径，相应地加快了锂扩散速率，这有利于快速充电特性。因此，铌钨氧化物在半电池中表现出优异的长期循环寿命（在10C下1000次循环中为135 mAh g）和超高电流密度（≈103.9 mAh g，100C）下的倍率性能。原位X射线衍射和拉曼光谱结合扫描电子显微镜清楚地证实了晶体和微观结构的稳定性。此外，制备的铌钨氧化物||磷酸铁锂全电池表现出显著的功率密度，并展示出可逆的比容量。软包电池具有长循环寿命（在10C下5000次循环后容量保持率高达96.6%）和高安全性能。因此，纳米尺寸的铌钨氧化物可被认为是下一代实用LIBs中一种有前景的快速充电阳极材料。
