Continuous Hydrothermal Synthesis of Metal Germanates ( M 2 GeO 4 ; M = Co, Mn, Zn) for High-Capacity Negative Electrodes in Li-Ion Batteries
Continuous Hydrothermal Synthesis of Metal Germanates ( M 2 GeO 4 ; M = Co, Mn, Zn) for High-Capacity Negative Electrodes in Li-Ion Batteries
复制标题
连续水热合成金属锗酸盐（M 2 GeO 4 ；M = Co、Mn、Zn）用于锂离子电池高容量负极
DOI：
10.1002/ente.201900692
复制
发表时间：
2019
影响因子：
3.8
通讯作者：
Bauer D
中科院分区：
文献类型：
--
作者：
Bauer D
首次采用连续水热法合成了纳米金属锗酸盐（M2 GeO 4;M= Co，Mn，Zn）。探索了所有样品作为锂离子半电池负极活性材料的电化学性能。在相对于Li/Li+的3.00-0.05 V电位范围内进行恒电流和动电位测试。结果表明，与Ge相关的合金化和转化反应都有助于存储电荷容量;由于Ge和Zn的合金化和转化反应，Zn 2GeO 4显示出600 mAh g−1的高比容量（在0.1 A g−1下十次循环）。首次研究了Mn 2GeO 4作为锂离子半电池中潜在的负极材料;获得了510 mAh g−1（10次循环/0.1 A g−1）的优异比电荷容量，对脱锂时Mn向MnO的转化反应产生的电荷有显著贡献。相比之下，Co2 GeO 4在相同电流速率下循环10次后仅显示出240 mAh g−1的比容量，这表明钴对增强锗酸盐中的存储电荷几乎没有益处。
Nanosized metal germanates (M2GeO4;M= Co, Mn, Zn) are synthesized using a continuous hydrothermal flow synthesis process for the first time. The electrochemical properties of all samples as active materials for negative electrodes in Li‐ion half cells are explored. The galvanostatic and potentiodynamic testing is conducted in the potential range of 3.00–0.05 V versus Li/Li+. The results suggest that both alloying and conversion reactions associated with Ge contribute to the stored charge capacity; Zn2GeO4shows a high specific capacity of 600 mAh g−1(ten cycles at 0.1 A g−1) due to alloying and conversion reactions for both Ge and Zn. Mn2GeO4is studied for the first time as a potential negative electrode material in a Li‐ion half cell; an excellent specific charge capacity of 510 mAh g−1(10 cycles per 0.1 A g−1) is obtained with a significant contribution to charge arising from the conversion reaction of Mn to MnO upon delithiation. In contrast, Co2GeO4only shows a specific capacity of 240 mAh g−1, after ten cycles at the same current rate, which suggests that cobalt has little or no benefit for enhancing stored charge in germanate.