He Jun, Wei Yaqing, Hu Lintong, Li Huiqiao, Zhai Tianyou
State Key Laboratory of Material Processing and Die and Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, China.
Shenzhen Research Institute of Huazhong University of Science and Technology, Shenzhen, China.
Front Chem. 2018 Feb 12;6:21. doi: 10.3389/fchem.2018.00021. eCollection 2018.
GeP is a recently reported new anode material for lithium ion batteries (LIBs), it holds a large theoretical capacity about 2300 mAh g, and a high rate capability due to its bi-active components and superior conductivity. However, it undergoes a large volume change during its electrochemical alloying and de-alloying with Li, a suitable binder is necessary to stable the electrode integrity for improving cycle performance. In this work, we tried to apply aqueous binders LiPAA and NaCMC to GeP anode, and compared the difference in electrochemical performance between them and traditional binder PVDF. As can be seen from the test result, GeP can keep stable in both common organic solvents and proton solvents such as water and alcohol solvents, it meets the application requirements of aqueous binders. The electrochemistry results show that the use of LiPAA binder can significantly improve the initial Coulombic efficiency, reversible capacity, and cyclability of GeP anode as compared to the electrodes based on NaCMC and PVDF binders. The enhanced electrochemical performance of GeP electrode with LiPAA binder can be ascribed to the unique high strength long chain polymer structure of LiPAA, which also provide numerous uniform distributed carboxyl groups to form strong ester groups with active materials and copper current collector. Benefit from that, the GeP electrode with LiPAA can also exhibit excellent rate capability, and even at low temperature, it still shows attractive electrochemical performance.
锗磷（GeP）是最近报道的一种用于锂离子电池（LIBs）的新型负极材料，它具有约2300 mAh g的大理论容量，并且由于其双活性成分和优异的导电性而具有高倍率性能。然而，它在与锂进行电化学合金化和脱合金化过程中会发生较大的体积变化，因此需要一种合适的粘结剂来稳定电极完整性以提高循环性能。在这项工作中，我们尝试将水性粘结剂锂聚丙烯酸（LiPAA）和羧甲基纤维素钠（NaCMC）应用于GeP负极，并比较它们与传统粘结剂聚偏氟乙烯（PVDF）在电化学性能上的差异。从测试结果可以看出，GeP在常见的有机溶剂以及质子溶剂（如水和醇类溶剂）中都能保持稳定，满足水性粘结剂的应用要求。电化学结果表明，与基于NaCMC和PVDF粘结剂的电极相比，使用LiPAA粘结剂可以显著提高GeP负极的初始库仑效率、可逆容量和循环性能。具有LiPAA粘结剂的GeP电极电化学性能的增强可归因于LiPAA独特的高强度长链聚合物结构，它还提供了大量均匀分布的羧基，与活性材料和铜集流体形成强酯基。得益于此，具有LiPAA的GeP电极也表现出优异的倍率性能，甚至在低温下，它仍然显示出有吸引力的电化学性能。
