Nanostructured metal sulfides are potential electrode materials for sodium-ion batteries; however, they typically suffer from very poor cycling stability due to large volume changes and dissolution of discharge produc...Nanostructured metal sulfides are potential electrode materials for sodium-ion batteries; however, they typically suffer from very poor cycling stability due to large volume changes and dissolution of discharge products. Herein we propose a rational material design strategy for sulfide-based materials to address these problems. Taking nickel sulfide （NiSx） as an example, we demonstrated that its electrochemical performance can be dramatically improved by confining the NiSx nanoparticles in a percolating conductive carbon nanotube network, and stabilizing them with an ultrathin carbon coating layer. The carbon layer serves as a physical barrier to alleviate the effects of both the volume change and dissolution of active materials. The hybrid material exhibited a large reversible specific capacity of 〉500 mAh/g and excellent cycling stability over 200 cycles. Given the traditionally problematic nature of NiSx as a battery anode material, we believe that the observed high performance reported here reflects the effectiveness of our material design strategy.展开更多
基金The authors greatly acknowledge the financial support from the National Natural Science Foundation of China （Nos. 51472173 and 51522208）, the Natural Science Foundation of Jiangsu Province （Nos. BK20140302 and SBK2015010320）, the Priority Academic Program Development of Jiangsu Higher Education Institutions and Collaborative Innovation Center of Suzhou Nano Science and Technology.
文摘Nanostructured metal sulfides are potential electrode materials for sodium-ion batteries; however, they typically suffer from very poor cycling stability due to large volume changes and dissolution of discharge products. Herein we propose a rational material design strategy for sulfide-based materials to address these problems. Taking nickel sulfide （NiSx） as an example, we demonstrated that its electrochemical performance can be dramatically improved by confining the NiSx nanoparticles in a percolating conductive carbon nanotube network, and stabilizing them with an ultrathin carbon coating layer. The carbon layer serves as a physical barrier to alleviate the effects of both the volume change and dissolution of active materials. The hybrid material exhibited a large reversible specific capacity of 〉500 mAh/g and excellent cycling stability over 200 cycles. Given the traditionally problematic nature of NiSx as a battery anode material, we believe that the observed high performance reported here reflects the effectiveness of our material design strategy.
