Chen Xu, Zhou Jian, Li Jiarui, Luo Haiyan, Mei Lin, Wang Tao, Zhu Jian, Zhang Yong
State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry Institution, Hunan University Changsha 410082 China
Fujian Provincial Key Laboratory of Functional Materials and Applications, Xiamen University of Technology Xiamen 361024 China.
RSC Adv. 2019 Oct 30;9(60):35045-35049. doi: 10.1039/c9ra06023e. eCollection 2019 Oct 28.
High-performance lithium ion batteries are ideal energy storage devices for both grid-scale and large-scale applications. Germanium, possessing a high theoretical capacity, is a promising anode material for lithium ion batteries, but still faces poor cyclability due to huge volume changes during the lithium alloying/dealloying process. Herein, we synthesized an amorphous germanium and zinc chalcogenide (GZC) with a hierarchically porous structure a solvothermal reaction. As an anode material in a lithium ion battery, the GZC electrode exhibits a high reversible capacity of 747 mA h g after 350 cycles at a current density of 100 mA g and a stable capacity of 370 mA h g after 500 cycles at a current density of 1000 mA g along with 92% capacity retention. All of these outstanding electrochemical properties are attributed to the hierarchically porous structure of the electrode that has a large surface area, fast ion conductivity and superior structural stability, which buffers the volumetric variation during charge/discharge processes and also makes it easier for the electrolyte to soak in, affording more electrochemically active sites.
高性能锂离子电池是适用于电网规模和大规模应用的理想储能装置。锗具有较高的理论容量，是一种很有前景的锂离子电池负极材料，但由于在锂合金化/脱合金化过程中体积变化巨大，其循环性能仍然较差。在此，我们通过溶剂热反应合成了一种具有分级多孔结构的非晶态锗硫属化物（GZC）。作为锂离子电池的负极材料，GZC电极在100 mA g的电流密度下循环350次后表现出747 mA h g的高可逆容量，在1000 mA g的电流密度下循环500次后表现出370 mA h g的稳定容量以及92%的容量保持率。所有这些优异的电化学性能都归因于电极的分级多孔结构，该结构具有大表面积、快速离子传导率和优异的结构稳定性，可缓冲充放电过程中的体积变化，还使电解质更容易浸入，提供更多的电化学活性位点。
