Representative Ge-rich binary Co–Ge compounds (CoGe, Co₅Ge₇, and CoGe₂) are synthesized by facile solid-state reactions and apply as Li-ion battery (LIB) anode materials. Among the binary Co–Ge compounds studied, CoGe₂ shows the highest Li reversibility. Thus, a CoGe₂-decorated carbon composite (CoGe₂@C) is prepared to improve the electrochemical performance of CoGe₂. Ex situ analysis results of X-ray diffraction and extended X-ray absorption fine structure demonstrate that the CoGe₂@C has an interesting mechanism of conversion/recombination during Li insertion/extraction. Owing to this continual conversion/recombination mechanism during cycling, the CoGe₂@C shows superior electrochemical performance. Specifically, CoGe₂@C shows high reversible capacity (1,106 and 973 mAh/cm³ at current density of 50 and 100 mA/g, respectively), stable cycling behavior (93.3% and 98.8% capacity retention at a cycling rate of 50 mA/g and 100 mA/g, respectively, after 100 cycling), and fast rate capability with stable cycling behavior (~700 mAh/cm³ at 1C rate over 200 cycles). Therefore, CoGe₂@C can be used as a high-performance LIB anode material.

具有代表性的富含Ge的二元Co-Ge化合物（CoGe，Co ₅ Ge ₇和CoGe ₂）是通过容易的固态反应合成的，并用作锂离子电池（LIB）阳极材料。在研究的二元Co-Ge化合物中，CoGe ₂显示出最高的Li可逆性。因此，制备了装饰CoGe _2的碳复合材料（CoGe ₂ @C）以改善CoGe ₂的电化学性能。易地X射线衍射和扩展X射线吸收精细结构的分析结果表明，该CoGe ₂@C具有在Li插入/提取过程中转换/重组的有趣机制。由于在循环过程中这种连续的转化/重组机制，CoGe ₂ @C表现出优异的电化学性能。具体而言，CoGe ₂ @C表现出高可逆容量（ 在电流密度分别为50和100 mA / g时分别为1,106和973 mAh / cm ³），稳定的循环行为（在50 mA的循环速率下容量保持率为93.3％和98.8％） / g和100 mA / g（分别在100次循环后）和快速速率能力以及稳定的循环行为（ 在200次循环中以1C速率约700 mAh / cm ³）。因此，CoGe ₂ @C可用作高性能的LIB阳极材料。