Liu Huan, Wu Tianhao, Zhang Liqiang, Wang Xin, Li Haifeng, Liu Shiqi, Zhang Qi, Zhang Xu, Yu Haijun
Institute of Advanced Battery Materials and Devices, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing, 100124, People's Republic of China.
Key Laboratory of Advanced Functional Materials, Ministry of Education, Beijing University of Technology, Beijing, 100124, People's Republic of China.
ACS Nano. 2022 Sep 27;16(9):14402-14411. doi: 10.1021/acsnano.2c04748. Epub 2022 Sep 2.
Germanium (Ge)-based materials can serve as promising anode candidates for high-energy lithium-ion batteries (LIBs). However, the rapid capacity decay caused by huge volume expansion severely retards their application. Herein, we report a facile and controllable synthesis of Ge nanowire anode materials through molten-salt electrolysis. The optimal Ge nanowires can deliver a capacity of 1058.9 mAh g at 300 mA g and a capacity above 602.5 mAh g at 3000 mA g for 900 cycles. By transmission electron microscopy and X-ray diffraction, the multiple-step phase transformation and good structural reversibility of the Ge nanowires during charge/discharge are elucidated. When coupled with a lithium-rich LiMnNiCoO cathode in a full battery, the Ge nanowire anode leads to a relatively stable capacity with a retention of 84.5% over 100 cycles. This research highlights the significance of molten-salt electrolysis for the synthesis of alloy-type anode materials toward high-energy LIBs.
锗（Ge）基材料有望成为高能锂离子电池（LIBs）的阳极候选材料。然而，巨大的体积膨胀导致的快速容量衰减严重阻碍了它们的应用。在此，我们报告了一种通过熔盐电解简便可控地合成锗纳米线阳极材料的方法。优化后的锗纳米线在300 mA g电流下可提供1058.9 mAh g的容量，在3000 mA g电流下900次循环后容量高于602.5 mAh g。通过透射电子显微镜和X射线衍射，阐明了锗纳米线在充放电过程中的多步相变和良好的结构可逆性。当在全电池中与富锂LiMnNiCoO阴极耦合时，锗纳米线阳极导致相对稳定的容量，在100次循环后保持率为84.5%。这项研究突出了熔盐电解对于合成用于高能锂离子电池的合金型阳极材料的重要性。
