Exploring the desired anode materials to address the issues of poor structural stability tardy redox kinetics caused by large potassium ionic radius are fatal for the realization of large-scale applications of potassi...Exploring the desired anode materials to address the issues of poor structural stability tardy redox kinetics caused by large potassium ionic radius are fatal for the realization of large-scale applications of potassium-ion batteries.In this work,the feasibility to achieve promoted K^(+)storage by constructing the model of CoS_(2)enfolded in carbon was verified by the density functional theory calculations.And the results predicted a faster electron/potassium ion transport kinetics than bare CoS_(2)by increasing electron carrier density and narrowing diffusion barrier.Therefore,an interfacial engineering strategy was applied and implemented to synthesize the CoS_(2)nanoparticles enveloped in the S-doped carbon(CoS_(2)/SC)under this inspiration.The as-prepared CoS_(2)/SC composite exhibited a prominent rate capability and long cycling lifespan,delivering the high capacity of 375 mA h g^(-1)at 0.2 A g^(-1)at the 100th cycle and 273 mA h g^(-1)at 2 A g^(-1)over 300 cycles.The in/ex situ characterizations unraveled the converse mechanism of CoS_(2)/SC in K^(+)storage,showing an eventually reversible phase transformation of K_(x)CoS_(2)Co↔within the electrochemical reactions.展开更多
基金The National Natural Science Foundation of China(Grant No.21701144)Opening Foundation of State Key Laboratory of Chemistry and Utilization of Carbon-based Energy Resource of Xinjiang University(Grant No.KFKT2021004)are gratefully acknowledged.
文摘Exploring the desired anode materials to address the issues of poor structural stability tardy redox kinetics caused by large potassium ionic radius are fatal for the realization of large-scale applications of potassium-ion batteries.In this work,the feasibility to achieve promoted K^(+)storage by constructing the model of CoS_(2)enfolded in carbon was verified by the density functional theory calculations.And the results predicted a faster electron/potassium ion transport kinetics than bare CoS_(2)by increasing electron carrier density and narrowing diffusion barrier.Therefore,an interfacial engineering strategy was applied and implemented to synthesize the CoS_(2)nanoparticles enveloped in the S-doped carbon(CoS_(2)/SC)under this inspiration.The as-prepared CoS_(2)/SC composite exhibited a prominent rate capability and long cycling lifespan,delivering the high capacity of 375 mA h g^(-1)at 0.2 A g^(-1)at the 100th cycle and 273 mA h g^(-1)at 2 A g^(-1)over 300 cycles.The in/ex situ characterizations unraveled the converse mechanism of CoS_(2)/SC in K^(+)storage,showing an eventually reversible phase transformation of K_(x)CoS_(2)Co↔within the electrochemical reactions.
