Selenium cathode has been demonstrated as a promising candidate of cathode material for low-cost and high-energy density potassium ion batteries(PIBs).Nevertheless,their applica tions are prevented by poor electrochem...Selenium cathode has been demonstrated as a promising candidate of cathode material for low-cost and high-energy density potassium ion batteries(PIBs).Nevertheless,their applica tions are prevented by poor electrochemical perfor-mance due to the shuttle effect of high-order polyselenides,the sluggish diffu-sion of bigger K+,and the huge volumetric expansion during cycling.In this work,we design a multifunctional Se host(N-HCNS)by grafting ZIF-8 derived microporous carbon onto the surface of N-doped porous carbon nanosheets.The obtained N-HCNS carbon matrix integrates conductivity,captivity,and immobility abilities,which inhibits the polyselenides shuttle,improves the Se utilization,and buffers the volume change during cycling.The 3D hollow car-bon skeleton enhances the infiltration of electrolytes.As an cathode for PIBs,the Se@N-HCNS electrode delivers an unprecedented life-span(260 mAh g1 at 1.0 Ag-1 after 2000 cycles)and exhibits a remarkable rate capacity(339 mAh g at 5.0 Ag-l).Density functional theory(DFT)calculation reveals the effective adsorption of K2Se with pyridine and pyrrole nitrogen dop-ing in carbon matrix.The unique synergetic design of electrode not only gives insight into the reaction mechanism but also highly emphasi zes the potential capabilities of N doped carbon in K-Se batteries.展开更多
基金China Postdoctoral Science Foundation,Grant/Award Number:2020M682031National Postdoctoral Program for Innovative Talents,Grant/Award Number:BX20200318+3 种基金National Synchrotron Radiation Laboratory,Grant/Award Num ber.KY2060000173Fundamental Research Funds for Central Universities,Grant/Award Number:WK 2060140026Dalian National Laboratory(DNL)Cooperation Fund for Clean Energy,Grant/Award Num ber:DNL 180310National Natural Science Foundation of China,Grant/Award Numbers:51972067,52002083,5187277,51925207,U1910210。
文摘Selenium cathode has been demonstrated as a promising candidate of cathode material for low-cost and high-energy density potassium ion batteries(PIBs).Nevertheless,their applica tions are prevented by poor electrochemical perfor-mance due to the shuttle effect of high-order polyselenides,the sluggish diffu-sion of bigger K+,and the huge volumetric expansion during cycling.In this work,we design a multifunctional Se host(N-HCNS)by grafting ZIF-8 derived microporous carbon onto the surface of N-doped porous carbon nanosheets.The obtained N-HCNS carbon matrix integrates conductivity,captivity,and immobility abilities,which inhibits the polyselenides shuttle,improves the Se utilization,and buffers the volume change during cycling.The 3D hollow car-bon skeleton enhances the infiltration of electrolytes.As an cathode for PIBs,the Se@N-HCNS electrode delivers an unprecedented life-span(260 mAh g1 at 1.0 Ag-1 after 2000 cycles)and exhibits a remarkable rate capacity(339 mAh g at 5.0 Ag-l).Density functional theory(DFT)calculation reveals the effective adsorption of K2Se with pyridine and pyrrole nitrogen dop-ing in carbon matrix.The unique synergetic design of electrode not only gives insight into the reaction mechanism but also highly emphasi zes the potential capabilities of N doped carbon in K-Se batteries.
