Manipulating selenium molecular configuration in N/O dual-doped porous carbon for high performance potassium-ion storage  

作　　者：Dongjun Li Lifeng Wang Xiaolong Cheng Yu Yao Yu Jiang Pengcheng Shi Ying Wu Xiaojun Wu Cheng Ma Yan Yua 

机构地区：[1]Hefei National Laboratory for Physical Sciences at the Microscale,Department of Materials Science and Engineering,CAS Key Laboratory of Materials for Energy Conversion,University of Science and Technology of China,Hefei 230026,Anhui,China [2]Dalian National Laboratory for Clean Energy(DNL),Chinese Academy of Sciences(CAS),Dalian 116023,Liaoning,China [3]School of Materials and Energy,Guangdong University of Technology,Guangzhou 510006,Guangdong,China [4]National Synchrotron Radiation Laboratory,Hefei 230026,Anhui,China

出　　处：《Journal of Energy Chemistry》2021年第11期581-589,I0014,共10页能源化学（英文版）

基　　金：This work was supported by the National Key R&D Research Program of China(Nos.2018YFA0209600,2017YFA0208300);the National Natural Science Foundation of China(Nos.51925207,U1910210,51872277,52002083,22005292,51802302);the DNL cooperation Fund,CAS(DNL180310);the Fundamental Research Funds for the Central Universities(WK2060140026,WK3430000006,WK2060000009);the National Synchrotron Radiation Laboratoi-y(KY2060000173);the National Postdoctoral Program for Innovative Talents(BX20200318);the China Postdoctoral Science Foundation(Nos.2020M672533,2019TQ0296,2020M682012).

摘　　要：Potassium-selenium(K-Se)batteries have attracted more and more attention because of their high theoretical specific capacity and natural abundance of K resources.However,dissolution of polyselenides,large volume expansion during cycling and low utilization of Se remain great challenges,leading to poor rate capability and cycle life.Herein,N/O dual-doped carbon nanofibers with interconnected micro/mesopores(MMCFs)are designed as hosts to manipulate Se molecular configuration for advanced flexible K-Se batteries.The micropores play a role in confining small Se molecule(Se_(2–3)),which could inhibit the formation of polyselenides and work as physical barrier to stabilize the cycle performance.While the mesopores can confine long-chain Se(Se_(4–7)),promising sufficient Se loading and contributing to higher discharge voltage of the whole Se@MMCFs composite.The N/O co-doping and the 3D interpenetrating nanostructure improve electrical conductivity and keep the structure integrity after cycling.The obtained Se_(2–3)/Se_(4–7)@MMCFs electrode exhibits an unprecedented cycle life(395 mA h g^(−1) at 1 A g^(−1) after 2000 cycles)and high specific energy density(400 Wh kg^(−1),nearly twice the specific energy density of the Se_(2–3)@MMCFs).This study offers a rational design for the realization of a high energy density and long cycle life chalcogen cathode for energy storage.

关 键 词：Carbon nanofibers with interconnected micro/mesopores Manipulating Se molecules Heteroatom-doping Flexible K-Se batteries 

分 类 号：TM912[电气工程—电力电子与电力传动] TQ342[化学工程—化纤工业]