3D silicon/graphite composite electrodes for high-energy lithium-ion batteries
3D silicon/graphite composite electrodes for high-energy lithium-ion batteries
复制标题
DOI：
10.1016/j.electacta.2019.05.064
复制
发表时间：
2019-09
影响因子：
6.6
通讯作者：
Yijing Zheng;H. Seifert;Huifeng Shi;Yuefei Zhang;C. Kübel;Wilhelm Pfleging
中科院分区：
文献类型：
--
作者：
Yijing Zheng;H. Seifert;Huifeng Shi;Yuefei Zhang;C. Kübel;Wilhelm Pfleging
与硅混合的石墨复合电极被提出作为下一代高能量和高功率应用的阳极材料。为了克服电化学循环过程中硅颗粒体积变化引起的缺点，并在增强的C-速率下保持高比容量，通过应用超快激光烧蚀在硅/石墨电极上产生自支撑结构。电化学性能进行了系统的研究，通过恒电流测量，循环伏安法，电化学阻抗谱。与具有非结构化电极的电池相比，具有结构化电极的电池表现出改善的电池性能和锂离子传输动力学。此外，具有结构化电极的电池在完全锂化状态下表现出较低的阻抗。在循环之后，进行事后分析，揭示了由于激光产生的独立结构，电极和集电器内的机械应力可以显著降低。
Graphite composite electrodes mixed with silicon are proposed as next generation anode material for high energy and high power applications. In order to overcome drawbacks caused by volume changes of silicon particles during electrochemical cycling and to maintain high specific capacities at enhanced C-rates, free-standing structures are generated on silicon/graphite electrodes by applying ultrafast laser ablation. Electrochemical properties are systematically investigated by means of galvanostatic measurements, cyclic voltammetry, and electrochemical impedance spectroscopy. Cells with structured electrodes exhibit improved battery performances and lithium-ion transport kinetics in comparison to cells with unstructured electrodes. Furthermore, the cells with structured electrodes exhibit a lower impedance at fully lithiated state. After cycling, post-mortem analysis is performed revealing that the mechanical stress within the electrodes and current collector can be significantly reduced due to laser generated free-standing structures.