Magnesium rechargeable batteries(MRBs)present opportunities for grid-scale energy storage applications as a complement to Li-ion batteries(LIBS).The major challenges are the low reversible capacity,inferior cycling st...Magnesium rechargeable batteries(MRBs)present opportunities for grid-scale energy storage applications as a complement to Li-ion batteries(LIBS).The major challenges are the low reversible capacity,inferior cycling stability and unsatisfactory energy densities.Na_(3)VCr_(0.5)Fe_(0.5)(PO_(4))_(3) with a well-defined NASIONtype structure is used as cathode in Mg cell.Two-electrons reaction(~116 m Ah/g),1.5 V average voltage and 65%of capacity retention over 100 cycles are accomplished.Mg is inserted by a biphasic reaction with the participation of V3+/V4+/V5+redox couples in the electrochemical reaction while the non-active redox couples such as Cr^(3+)/Cr^(4+)and Fe^(2+)/Fe^(3+)served as stabilizer to buffer the volume variation.A thermal stability up to~412℃ is also exhibited.Therefore,incorporating a mixture of three transition metal(V/Cr/Fe)in this type of structures will broaden new perspectives for realizing high performance cathodes for MRBs.展开更多
基金supported by the Scientific Research Funds of Huaqiao University and Xiamen University Foreign Young Talents Program(No.G2022149004L)。
文摘Magnesium rechargeable batteries(MRBs)present opportunities for grid-scale energy storage applications as a complement to Li-ion batteries(LIBS).The major challenges are the low reversible capacity,inferior cycling stability and unsatisfactory energy densities.Na_(3)VCr_(0.5)Fe_(0.5)(PO_(4))_(3) with a well-defined NASIONtype structure is used as cathode in Mg cell.Two-electrons reaction(~116 m Ah/g),1.5 V average voltage and 65%of capacity retention over 100 cycles are accomplished.Mg is inserted by a biphasic reaction with the participation of V3+/V4+/V5+redox couples in the electrochemical reaction while the non-active redox couples such as Cr^(3+)/Cr^(4+)and Fe^(2+)/Fe^(3+)served as stabilizer to buffer the volume variation.A thermal stability up to~412℃ is also exhibited.Therefore,incorporating a mixture of three transition metal(V/Cr/Fe)in this type of structures will broaden new perspectives for realizing high performance cathodes for MRBs.
