Kim Woo Seob, Vo Thuan Ngoc, Kim Il Tae
Department of Chemical and Biological Engineering, Gachon University, Seongnam-si, Gyeonggi-do 13120, Korea.
Materials (Basel). 2020 Sep 23;13(19):4222. doi: 10.3390/ma13194222.
Germanium boasts a high charge capacity, but it has detrimental effects on battery cycling life, owing to the significant volume expansion that it incurs after repeated recharging. Therefore, the fabrication of Ge composites including other elements is essential to overcome this hurdle. Herein, highly conductive Te is employed to prepare an alloy of germanium telluride (GeTe) with the addition of a highly conductive matrix comprising titanium carbide (TiC) and carbon (C) via high-energy ball milling (HEBM). The final alloy composite, GeTe-TiC-C, is used as a potential anode for lithium-ion cells. The GeTe-TiC-C composites having different combinations of TiC are characterized by electron microscopies and X-ray powder diffraction for structural and morphological analyses, which indicate that GeTe and TiC are evenly spread out in the carbon matrix. The GeTe electrode exhibits an unstable cycling life; however, the addition of higher amounts of TiC in GeTe offers much better electrochemical performance. Specifically, the GeTe-TiC (20%)-C and GeTe-TiC (30%)-C electrodes exhibited excellent reversible cyclability equivalent to 847 and 614 mAh g after 400 cycles, respectively. Moreover, at 10 A g, stable capacity retentions of 78% for GeTe-TiC (20%)-C and 82% for GeTe-TiC (30%)-C were demonstrated. This proves that the developed GeTe-TiC-C anodes are promising for potential applications as anode candidates for high-performance lithium-ion batteries.
锗具有高电荷容量,但由于其在反复充电后会产生显著的体积膨胀,对电池的循环寿命有不利影响。因此,制备包含其他元素的锗复合材料对于克服这一障碍至关重要。在此,通过高能球磨(HEBM),采用高导电性的碲来制备碲化锗(GeTe)合金,并添加由碳化钛(TiC)和碳(C)组成的高导电性基体。最终的合金复合材料GeTe-TiC-C被用作锂离子电池的潜在负极。通过电子显微镜和X射线粉末衍射对具有不同TiC组合的GeTe-TiC-C复合材料进行结构和形态分析,结果表明GeTe和TiC均匀分布在碳基体中。GeTe电极的循环寿命不稳定;然而,在GeTe中添加更多量的TiC可提供更好的电化学性能。具体而言,GeTe-TiC(20%)-C和GeTe-TiC(30%)-C电极在400次循环后分别表现出相当于847和614 mAh g的优异可逆循环性。此外,在10 A g的电流下,GeTe-TiC(20%)-C的稳定容量保持率为78%,GeTe-TiC(30%)-C的稳定容量保持率为82%。这证明所开发的GeTe-TiC-C负极作为高性能锂离子电池负极候选材料具有潜在应用前景。