A high-concentrated and nonflammable electrolyte for potassium ion-based dual-graphite batteries  

作　　者：Kexin Li Guiyou Ma Dandan Yu Wen Luo Jiaxin Li Laishun Qin Yuexiang Huang Da Chen 

机构地区：[1]College of Materials and Chemistry,China Jiliang University,Hangzhou 310018,China [2]Liangxin College,China Jiliang University,Hangzhou 310018,China

出　　处：《Nano Research》2023年第5期6353-6360,共8页纳米研究（英文版）

基　　金：the National Natural Science Foundation of China(Nos.52002081,51972294,and 51872271).

摘　　要：Potassium ion-based dual-graphite batteries(KDGBs)emerge as promising devices for large-scale applications due to their high voltage,low cost,environmental friendliness.However,conventional KPF6/carbonate-based electrolytes suffer from severe oxidation decomposition,low concentration,flammability,which limit the capacity and cyclability of KDGBs.Herein,a nonflammable potassium bis(fluorosulfonyl)imide/triethyl phosphate(KFSI/TEP)electrolyte was designed for KDGBs.When the salt-to-solvent molar ratio increases to 1:1.3,graphite cathode operated at the cut-off potential of 5.2 V exhibits much enhanced capacity,excellent rate capability(26.4 mAh∙g^(−1) at 1.0 A∙g^(−1)),superior cyclability with 98%capacity retention after 350 cycles.Inorganic compounds-rich electrode/electrolyte interphase layers derived from the preferential decomposition of FSI−anions ensure good compatibility of the 1:1.3 KFSI/TEP electrolyte with K metal and graphite anodes.Based on this electrolyte,asassembled KDGBs show high operation voltage of 4.3 V and good cycling performance.This work provides feasibility for developing long-life and safe-operation DGBs.

关 键 词：dual-ion batteries GRAPHITE high voltage high-concentrated electrolytes PHOSPHATES 

分 类 号：TM912[电气工程—电力电子与电力传动]