Bo Wang, Yafei Cheng, Hao Su
Jun 15, 2020
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0
Influential Citations
88
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Quality indicators
Journal
ChemSusChem
Abstract
Cobalt sulfides have been popularly used in energy storage field because of its high theoretical capacity and rich redox reactions. However, the issues of poor reaction kinetics, rapid capacity decay and severe polarization due to volume changes during electrochemical reaction are still huge challenges for cobalt sulfides in practical applications. Herein, we have synthesized cobalt sulfides yolk-shell spheres by phosphorus doping (P-CoS) to stabilize the structure of cobalt sulfides and improve its electronic/ion conductivity. Kinetic tests and density functional theory calculations confirm that the introduction of phosphorus into cobalt sulfides greatly reduces the diffusion barrier of Li + in the intrinsic structure, thereby improving the reaction kinetics of electrode materials during the Li + insertion/extraction process. In consequence, the P-CoS electrode delivers a high lithium storage capacity (781 mAh g -1 after 100 cycles at 0.2 A g -1 ), outstanding rate capability (489 mAh g -1 at 10 A g -1 ) and good long-term cycling stability (no obvious capacity decay over 4000 cycles at 5 A g -1 ). Especially for the sodium-ion batteries application, the P-CoS yolk-shell spheres show a remarkably reversible capacity of about 260 mAh g -1 at 2 A g -1 after 900 cycles.