High electrochemical stability and safety make Na+superionic conductor(NASICON)-class cathodes highly desirable for Na-ion batteries(SIBs).However,their practical capacity is limited,leading to low specific energy.Fur...High electrochemical stability and safety make Na+superionic conductor(NASICON)-class cathodes highly desirable for Na-ion batteries(SIBs).However,their practical capacity is limited,leading to low specific energy.Furthermore,the low electrical conductivity combined with a decline in capacity upon prolonged cycling(>1000 cycles)related to the loss of active material-carbon conducting contact regions contributes to moderate rate performance and cycling stability.The need for high specific energy cathodes that meet practical electrochemical requirements has prompted a search for new materials.Herein,we introduce a new carbon-coated Na_(3)VFe_(0.5)Ti_(0.5)(PO_(4))_(3)(NVFTP/C)material as a promising candidate in the NASICON family of cathodes for SIBs.With a high specific energy of∼457 Wh kg^(-1) and a high Na+insertion voltage of 3.0 V versus Na^(+)/Na,this cathode can undergo a reversible single-phase solid-solution and two-phase(de)sodiation evolution at 28 C(1 C=174.7 mAh g^(-1))for up to 10,000 cycles.This study highlights the potential of utilizing low-cost and highly efficient cathodes made from Earth-abundant and harmless materials(Fe and Ti)with enriched Na^(+)-storage properties in practical SIBs.展开更多
Sodium superionic conductors(NASICONs)show significant promise for application in the development of cathodes for sodium-ion batteries(SIBs).However,it remains a major challenge to develop the desired multi-electron r...Sodium superionic conductors(NASICONs)show significant promise for application in the development of cathodes for sodium-ion batteries(SIBs).However,it remains a major challenge to develop the desired multi-electron reaction cathode with a high specific capacity and energy density.Herein,we report a novel NASICON-type Na_(3.5)MnCr_(0.5)Ti_(0.5)(PO_(4))_(3)cathode obtained by combining electrospinning and stepwise sintering processes.This cathode exhibits a high discharge capacity of 160.4 mAh g^(−1)and operates at a considerable medium voltage of 3.2 V.The Na_(3.5)MnCr_(0.5)Ti_(0.5)(PO_(4))_(3)cathode undergoes a multi-electron redox reaction involving the Cr^(3+/4+)(4.40/4.31 V vs.Na/Na^(+)),Mn^(3+/4+)(4.18/4.03 V),Mn^(2+/3+)(3.74/3.41 V),and Ti^(3+/4+)(2.04/2.14 V)redox couples.This redox reaction enables a three-electron transfer during the Na+intercalation/de-intercalation processes.As a result,the Na_(3.5)MnCr_(0.5)Ti_(0.5)(PO_(4))_(3)demonstrates a significant enhancement in energy density,surpassing other recently reported SIB cathodes.The highly reversible structure evolution and small volume changes during cycling were demonstrated with in-situ X-ray diffraction,ensuring outstanding cyclability with 77%capacity retention after 500 cycles.Furthermore,a NMCTP@C//Sb@C full battery was fabricated,which delivered a high energy density of 421 Wh kg−1 and exhibited good cyclability with 75.7%capacity retention after 100 cycles.The rational design of composition regulation with multi-metal ion substitution holds the potential to unlock new possibilities in achieving high-performance SIBs.展开更多
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This work was supported by the National Research Foundation of Korea(NRF)Grant funded by the Korean government(MSIT)(NRF-2018R1A5A1025224 and NRF-2021R1A4A1052051)This work was also supported by the National Research Foundation of Korea Grant funded by the Korean Government Ministry of Education and Science Technology(NRF-2021R1I1A3060193).
文摘High electrochemical stability and safety make Na+superionic conductor(NASICON)-class cathodes highly desirable for Na-ion batteries(SIBs).However,their practical capacity is limited,leading to low specific energy.Furthermore,the low electrical conductivity combined with a decline in capacity upon prolonged cycling(>1000 cycles)related to the loss of active material-carbon conducting contact regions contributes to moderate rate performance and cycling stability.The need for high specific energy cathodes that meet practical electrochemical requirements has prompted a search for new materials.Herein,we introduce a new carbon-coated Na_(3)VFe_(0.5)Ti_(0.5)(PO_(4))_(3)(NVFTP/C)material as a promising candidate in the NASICON family of cathodes for SIBs.With a high specific energy of∼457 Wh kg^(-1) and a high Na+insertion voltage of 3.0 V versus Na^(+)/Na,this cathode can undergo a reversible single-phase solid-solution and two-phase(de)sodiation evolution at 28 C(1 C=174.7 mAh g^(-1))for up to 10,000 cycles.This study highlights the potential of utilizing low-cost and highly efficient cathodes made from Earth-abundant and harmless materials(Fe and Ti)with enriched Na^(+)-storage properties in practical SIBs.
基金supported by the National Natural Science Foundation of China(52302304,52102299,52102295)the Guangdong Basic and Applied Basic Research Foundation(2021A1515110059)+3 种基金the Natural Science Foundation of Hubei Provincial(2023AFB999)the Fundamental Research Funds for the Central Universities(WUT:2021IVA034B,2022-xcs4)Hainan Provincial Joint Project of Sanya Yazhou Bay Science and Technology City(520LH055)the Sanya Science and Education Innovation Park of Wuhan University of Technology(2021KF0019).
文摘Sodium superionic conductors(NASICONs)show significant promise for application in the development of cathodes for sodium-ion batteries(SIBs).However,it remains a major challenge to develop the desired multi-electron reaction cathode with a high specific capacity and energy density.Herein,we report a novel NASICON-type Na_(3.5)MnCr_(0.5)Ti_(0.5)(PO_(4))_(3)cathode obtained by combining electrospinning and stepwise sintering processes.This cathode exhibits a high discharge capacity of 160.4 mAh g^(−1)and operates at a considerable medium voltage of 3.2 V.The Na_(3.5)MnCr_(0.5)Ti_(0.5)(PO_(4))_(3)cathode undergoes a multi-electron redox reaction involving the Cr^(3+/4+)(4.40/4.31 V vs.Na/Na^(+)),Mn^(3+/4+)(4.18/4.03 V),Mn^(2+/3+)(3.74/3.41 V),and Ti^(3+/4+)(2.04/2.14 V)redox couples.This redox reaction enables a three-electron transfer during the Na+intercalation/de-intercalation processes.As a result,the Na_(3.5)MnCr_(0.5)Ti_(0.5)(PO_(4))_(3)demonstrates a significant enhancement in energy density,surpassing other recently reported SIB cathodes.The highly reversible structure evolution and small volume changes during cycling were demonstrated with in-situ X-ray diffraction,ensuring outstanding cyclability with 77%capacity retention after 500 cycles.Furthermore,a NMCTP@C//Sb@C full battery was fabricated,which delivered a high energy density of 421 Wh kg−1 and exhibited good cyclability with 75.7%capacity retention after 100 cycles.The rational design of composition regulation with multi-metal ion substitution holds the potential to unlock new possibilities in achieving high-performance SIBs.
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.
