A new organic cathode namely potassium 2,6-dihydroxyanthraquinone(AQ26OK,theoretical capacity(CT)=169 mA h g^(-1))is synthesized and fully characterized for Kion batteries.AQ26OK is called polyanionic organic cathode ...A new organic cathode namely potassium 2,6-dihydroxyanthraquinone(AQ26OK,theoretical capacity(CT)=169 mA h g^(-1))is synthesized and fully characterized for Kion batteries.AQ26OK is called polyanionic organic cathode because it has a polyanionic organic skeleton(-2 valent)and two strong ionic K-O bonds.Consequently,the polyanionic AQ26OK is hardly soluble into most organic liquid electrolytes.In half cells(0.3-3.4 V vs.K^(+)/K)using 1 mol L^(-1) KPF6 in dimethoxyethane,AQ26OK delivers a highly stable specific capacity of 201 mA h g^(-1)@50 mA g^(-1) over 450 cycles(4-month test)and realizes~106 mA h g^(-1) for 3200 cycles at 500 mA g^(-1).Using the reduced state(K4TP)of potassium terephthalate(K2TP)as the organic anode,the resulting K4TP Ⅱ AQ26OK organic potassium-ion batteries can display a highly stable average discharge capacity of 135 mA h g^(-1) cathodeover 250 cycles at 100 mA g^(-1) and~47 mA h g^(-1) for 1000 cycles at 500 mA g^(-1) during the working voltage of 0.01-3.1 V.To the best of our knowledge,AQ26OK is among the best stable cathodes reported for K-ion batteries.展开更多
基金supported by the Fundamental Research Funds of University of Electronic Science and Technology of China(UESTC,ZYGX2019J027)the Open Foundation of State Key Laboratory of Electronic Thin Films and Integrated Devices of UESTC(KFJJ201915)Sichuan Science and Technology Program(20YYJC3821)。
文摘A new organic cathode namely potassium 2,6-dihydroxyanthraquinone(AQ26OK,theoretical capacity(CT)=169 mA h g^(-1))is synthesized and fully characterized for Kion batteries.AQ26OK is called polyanionic organic cathode because it has a polyanionic organic skeleton(-2 valent)and two strong ionic K-O bonds.Consequently,the polyanionic AQ26OK is hardly soluble into most organic liquid electrolytes.In half cells(0.3-3.4 V vs.K^(+)/K)using 1 mol L^(-1) KPF6 in dimethoxyethane,AQ26OK delivers a highly stable specific capacity of 201 mA h g^(-1)@50 mA g^(-1) over 450 cycles(4-month test)and realizes~106 mA h g^(-1) for 3200 cycles at 500 mA g^(-1).Using the reduced state(K4TP)of potassium terephthalate(K2TP)as the organic anode,the resulting K4TP Ⅱ AQ26OK organic potassium-ion batteries can display a highly stable average discharge capacity of 135 mA h g^(-1) cathodeover 250 cycles at 100 mA g^(-1) and~47 mA h g^(-1) for 1000 cycles at 500 mA g^(-1) during the working voltage of 0.01-3.1 V.To the best of our knowledge,AQ26OK is among the best stable cathodes reported for K-ion batteries.
