High power and stable P-doped yolk-shell structured Si@C anode simultaneously enhancing conductivity and Li+ diffusion kinetics
Ming Chen, Qinnan Zhou, Jiantao Zai, Asma Iqbal, TsegayeTadesse Tsega, Boxu Dong, Xuejiao Liu, Yuchi Zhang, Changyu Yan, Liang Zhao, Ali Nazakat, SharelPeisan E, CheeTongJohn Low, Xuefeng Qian
Abstract
Abstract 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/SiO x 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 ∼ 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 LiFePO 4 cathode to assemble lithium-ion capacitor (high power density of ∼ 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.