Hollow-Carbon-Templated Few-Layered V5S8 Nanosheets Enabling Ultrafast Potassium Storage and Long-Term Cycling
RIS ID
137940
Abstract
Due to the abundant potassium resource on the Earth's crust, researchers now have become interested in exploring high-performance potassium-ion batteries (KIBs). However, the large size of K+ would hinder the diffusion of K ions into electrode materials, thus leading to poor energy/power density and cycling performance during the depotassiation/potassiation process. So, few-layered V5S8 nanosheets wrapping a hollow carbon sphere fabricated via a facile hollow carbon template induced method could reversibly accommodate K storage and maintain the structure stability. Hence, the as-obtained V5S8@C electrode enables rapid and reversible storage of K+ with a high specific capacity of 645 mAh/g at 50 mA/g, a high rate capability, and long cycling stability, with 360 and 190 mAh/g achieved after 500 and 1000 cycles at 500 and 2000 mA/g, respectively. The excellent electrochemical performance is superior to the most existing electrode materials. The DFT calculations reveal that V5S8 nanosheets have high electrical conductivity and low energy barriers for K+ intercalation. Furthermore, the reaction mechanism of the V5S8@C electrode in KIBs is probed via the in operando synchrotron X-ray diffraction technique, and it indicates that the V5S8@C electrode undergoes a sequential intercalation (KV5S8) and conversion reactions (K2S3) reversibly during the potassiation process.
Grant Number
ARC/FT150100109, ARC/DP170102406, ARC/DE190100504
Publication Details
Li, L., Zhang, W., Wang, X., Zhang, S., Liu, Y., Li, M., Zhu, G., Zheng, Y., Zhang, Q., Zhou, T., Pang, W., Luo, W., Guo, Z. & Yang, J. (2019). Hollow-Carbon-Templated Few-Layered V5S8 Nanosheets Enabling Ultrafast Potassium Storage and Long-Term Cycling. ACS Nano, 13 (7), 7939-7948.