The germanium high theoretical capacity renders it as a promising anode material with 1384 mAh/g for Li (Li₁₅Ge₄) and 369 mAh/g for Na (NaGe) and K (KGe). Nevertheless, Ge suffers from volume variations due to alkali insertion, to mitigate this issue several strategies have been proposed. Among them the use of layered Ge‐based phases, obtained from the CaGe₂ Zintl phase by topotactic deintercalation of Ca²⁺ to form the germanane (GeH)_n. This last one has a particular morphology of Ge₆ rings interconnected to form planes that buffers the volume changes and shortens the diffusion pathways. Here, we have studied the germanane alkali storage properties and 2150, 495 and 205 mAh/g of reversible capacity were obtained for Li, Na and K, respectively. These results indicate that germanane can store more alkali ions than the predicted phases, perform well at high rates and maintain a good capacity retention.

中文翻译：

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面向锗分层材料，作为锂离子，钠离子和钾离子电池的高级负极

锗的高理论容量使其成为有前途的负极材料，其中Li（Li ₁₅ Ge ₄）为1384 mAh / g，Na（NaGe）和K（KGe）为369 mAh / g。然而，Ge由于碱的插入而遭受体积变化的困扰，为了减轻这个问题，已经提出了几种策略。其中使用分层的基于Ge的相，该相通过从CaGe ₂ Zintl相通过Ca ²⁺的全位脱嵌形成锗烷（GeH）_n获得。最后一个具有特定形态的Ge ₆环相互连接形成平面，从而缓冲了体积变化并缩短了扩散路径。在这里，我们研究了锗烷的碱存储性能，并分别获得了Li，Na和K的2150、495和205 mAh / g的可逆容量。这些结果表明，锗烷比预期的相可以存储更多的碱离子，在高速率下表现良好，并保持良好的容量保持率。