High power and stable P-doped yolk-shell structured Si@C anode simultaneously enhancing conductivity and Li+ diffusion kinetics
High power and stable P-doped yolk-shell structured Si@C anode simultaneously enhancing conductivity and Li+ diffusion kinetics
复制标题
高功率、稳定的磷掺杂蛋黄壳结构Si@C阳极同时增强电导率和锂扩散动力学
DOI：
10.1007/s12274-020-3142-9
复制
发表时间：
2020-10-23
期刊：
影响因子：
9.9
通讯作者：
Qian, Xuefeng
中科院分区：
文献类型：
--
作者：
Chen, Ming;Zhou, Qinnan;Qian, Xuefeng
硅是一种低价高容量的锂离子电池负极材料。蛋黄-壳结构可以有效地容纳硅的膨胀，提高稳定性。然而，硅阳极的限倍率性能不能满足人们对高功率密度日益增长的需求。本文通过在掺磷的Si/SiOx基片上进行碳包覆，制备了掺磷蛋黄壳结构的Si@C材料(P掺杂的Si@C)，以获得高功率、稳定的器件。因此，所制备的P掺杂Si@C电极在6次循环后库仑效率从74.4%迅速提高到99.6%，在4A.G(-1)下800次循环的容量保持率接近95%，在35A.G(-1)下的高倍率容量(510mAh.g(-1))。结果表明，磷掺杂的Si@C负极分别与商业活性碳和LiFePO4正极组装成锂离子电容器(20A.G(-1)时的高功率密度接近61,080W·kg(-1))和锂离子全电池(5C时的倍率性能良好，为68.3mAh.g(-1))。这为进一步提高储能设备的功率密度和稳定性提供了有效的途径。
Silicon is a low price and high capacity anode material for lithium-ion batteries. The yolk-shell structure can effectively accommodate Si expansion to improve stability. However, the limited rate performance of Si anodes can't meet people's growing demand for high power density. Herein, the phosphorus-doped yolk-shell Si@C materials (P-doped Si@C) were prepared through carbon coating on P-doped Si/SiOx matrix to obtain high power and stable devices. Therefore, the as-prepared P-doped Si@C electrodes delivered a rapid increase in Coulombic efficiency from 74.4% to 99.6% after only 6 cycles, high capacity retention of similar to 95% over 800 cycles at 4 A.g(-1), and great rate capability (510 mAh.g(-1) at 35 A.g(-1)). As a result, P-doped Si@C anodes paired with commercial activated carbon and LiFePO4 cathode to assemble lithium-ion capacitor (high power density of similar to 61,080 W.kg(-1) at 20 A.g(-1)) and lithium-ion full cell (good rate performance with 68.3 mAh.g(-1) at 5 C), respectively. This work can provide an effective way to further improve power density and stability for energy storage devices.