The capacity decay of room temperature Na–S batteries is mainly caused by the poor electronic conductivity,shuttle effect,and volume expansion of sulfur/polysulfides(NaPSs).Herein,anthozoan-like nitrogen-doped porous...The capacity decay of room temperature Na–S batteries is mainly caused by the poor electronic conductivity,shuttle effect,and volume expansion of sulfur/polysulfides(NaPSs).Herein,anthozoan-like nitrogen-doped porous carbon nanocages with a nano-Co-armed carbon nanotube(CNT)multifunctional layer are proposed to improve the stability of Na–S batteries effectively.In this unique structure,the nano-Co-armed CNT functional layer not only enhances the adsorption of soluble NaPSs through Co–S bonding but also efficiently catalyzes their conversion to Na_(2)S_(x)(2≤x≤6).The hollow and porous nanocages provide a buffer space for volume expansion of the electrode material during the cycle.The nitrogen-doped highly graphitized carbon has high electronic conductivity.As the cathode material in room temperature(RT)Na–S batteries,the proposed material with a nano-Co-armed CNT functional layer delivered an improved stable electrochemical performance and achieved 314.8 mA h g^(-1)at 0.5 C with a 0.025% decay rate per cycle for 1000 cycles,high coulombic efficiency(∼100%),and excellent capacity rate(426.1 mA h g^(-1)at 0.1 C,351.8 mA h g^(-1)at 0.5 C,and 411.9 mA h g^(-1)when back to 0.1 C).展开更多
基金supported by the National Natural Science Foundation of China(21972111,21773188)Fundamental Research Funds for the Central Universities(XDJK2019B052,XDJK2019AA002)+2 种基金Natural Science Foundation of Chongqing(cstc2018jcyjAX0714)Venture&Innovation Support Program for Chongqing Overseas Returnees(cx2019073)Chongqing Engineering Research Center for Micro-Nano Biomedical Materials and Devices,and Chongqing Key Laboratory for Advanced Materials and Technologies.
文摘The capacity decay of room temperature Na–S batteries is mainly caused by the poor electronic conductivity,shuttle effect,and volume expansion of sulfur/polysulfides(NaPSs).Herein,anthozoan-like nitrogen-doped porous carbon nanocages with a nano-Co-armed carbon nanotube(CNT)multifunctional layer are proposed to improve the stability of Na–S batteries effectively.In this unique structure,the nano-Co-armed CNT functional layer not only enhances the adsorption of soluble NaPSs through Co–S bonding but also efficiently catalyzes their conversion to Na_(2)S_(x)(2≤x≤6).The hollow and porous nanocages provide a buffer space for volume expansion of the electrode material during the cycle.The nitrogen-doped highly graphitized carbon has high electronic conductivity.As the cathode material in room temperature(RT)Na–S batteries,the proposed material with a nano-Co-armed CNT functional layer delivered an improved stable electrochemical performance and achieved 314.8 mA h g^(-1)at 0.5 C with a 0.025% decay rate per cycle for 1000 cycles,high coulombic efficiency(∼100%),and excellent capacity rate(426.1 mA h g^(-1)at 0.1 C,351.8 mA h g^(-1)at 0.5 C,and 411.9 mA h g^(-1)when back to 0.1 C).
