As a promising cathode material,Na3V2(PO4)2F3(NVPF)has attracted wide attention for sodium-ion batteries(SIBs)because of its high operating voltage and high structural stability.However,the low intrinsic electronic conductivity and insufficient Na ion mobility of NVPF limit its development.Herein,K-doping NVPF is prepared through a facile ball-milling combined calcination method.The effects of K-doping on the crystal structure,kinetic properties and electrochemical performance are investigated.The results demonstrate that the Na2.90K0.10V2(PO4)3F3(K0.10-NVPF)exhibits a high capacity(120.8 mAh g-1 at 0.1 C),high rate capability(66 mAh g-1 at 30 C)and excellent cycling performance(a capacity retention of 97.5％at 1 C over 500 cycles).Also,the occupation site of K ions in the lattice,electronic band structure and Na-ion transport kinetic property in K-doped NVPF are investigated by density functional theory(DFT)calculations,which reveals that the K-doped NVPF exhibits improved electronic and ionic conductivities,and located K+ions in the lattice to contribute to high reversible capacity,rate capability and cycling stability.Therefore,the K-doped NVPF serves as a promising cathode material for high-energy and high-power SIBs.

Jiexin Zhang;Yang Yang Lai;Peng Li;Yanxia Wang;Faping Zhong;Xiangming Feng;Weihua Chen;Jianjun Liu;Xinping Ai;Hanxi Yang;Yuliang Cao

Engineering Research Center of Organosilicon Compounds&Materials of Ministry of Education,College of Chemistry and Molecular Sciences,Wuhan University,Wuhan,430072,China;National Engineering Research Center of Advanced Energy Storage Materials,Hunan,410205,China;College of Chemistry and Molecular Engineering,Zhengzhou University,Zhengzhou,450001,China;State Key Laboratory of High Performance Ceramics and Superfine Microstructure,Shanghai Institute of Ceramics,Chinese Academy of Sciences,1295 Dingxi Road,Shanghai,200050,China

绿色能源与环境（英文）

[1]Jiexin Zhang;Yang Yang Lai;Peng Li;Yanxia Wang;Faping Zhong;Xiangming Feng;Weihua Chen;Jianjun Liu;Xinping Ai;Hanxi Yang;Yuliang Cao-.Boosting rate and cycling performance of K-doped Na3V2(PO4)2F3 cathode for high-energy-density sodium-ion batteries)[J].绿色能源与环境（英文）,2022(06):1253-1262

90K0,10V2

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