화학공학소재연구정보센터
Materials Research Bulletin, Vol.80, 309-315, 2016
High electrochemical performances of hierarchical hydrangea macrophylla like NiCo2O4 and NiCo2S4 as anode materials for Li-ion batteries
In this work, hierarchical hydrangea macrophylla like NiCo2O4 has been synthesized by solvothermal method followed by calcination treatment in air. By using Na2S as sulfur source, the NiCo2O4 is converted into NiCo2S4. Such hierarchical NiCo2O4 exhibits a high specific capacity and excellent cycling stability (928 mAhg(-1) at a current density of 100 mAg(-1) after 100 cycles). Even at high current density of 2000 mAg(-1), the electrode still delivers a specific capacity of 371 mAhg(-1) after 50 cycles. When the NiCo2S4 is used as anode materials for lithium-ion batteries, a high discharge capacity of 1204 mAhg(-1) can be achieved. Meanwhile, the NiCo2S4 electrode displays good cycling stability and rate capability. The excellent electrochemical performances can be attributed to the unique porous structure, which can effectively reduce the diffusion length for lithium ions and electrons, and alleviate volume expansion during the charge-discharge processes. (C) 2016 Published by Elsevier Ltd.