Argyrodites,Li_(6)PS_(5)X(X=Cl,Br,I),have piqued the interest of researchers by offering promising lithium ionic conductivity for their application in all-solid-state batteries(ASSBs).However,other than Li_(6)PS_(5)Cl...Argyrodites,Li_(6)PS_(5)X(X=Cl,Br,I),have piqued the interest of researchers by offering promising lithium ionic conductivity for their application in all-solid-state batteries(ASSBs).However,other than Li_(6)PS_(5)Cl(651Cl)and Li_(6)PS_(5)Br(651Br),Li_(6)PS_(5)I(651I)shows poor ionic conductivity(10^(-7)S cm^(-1)at 298 K).Herein,we present Al-doped 651I with I^(-)/S^(2-)site disordering to lower activation energy(Ea)and improve ionic conductivity.They formed argyrodite-type solid solutions with a composition of(Li_(6–3x)Al_(x))PS_(5)I in 0≤x≤0.10,and structural analysis revealed that Al^(3+)is located at Li sites.Also,the Al-doped samples contained anion I^(-)/S^(2-)site disorders in the crystal structures and smaller lattice parameters than the non-doped samples.Impedance spectroscopy measurements indicated that Al-doping reduced the ionic diffusion barrier,Ea,and increased the ionic conductivity to 10^(-5)S cm^(-1);the(Li5.7Al0.1)PS5I had the highest ionic conductivity in the studied system,at 2.6×10^(-5)S cm^(-1).In a lab-scale ASSB,with(Li_(5.7)Al_(0.1))PS_(5)I functioned as a solid electrolyte,demonstrating the characteristics of a pure ionic conductor with negligible electronic conductivity.The evaluated ionic conduction is due to decreased Li+content and I^(-)/S^(2-)disorder formation.Li-site cation doping enables an in-depth understanding of the structure and provides an additional approach to designing betterperforming SEs in the argyrodite system.展开更多
基金supported by the Hundred-Talent Project of Hubei Province,China(Grant No.2021HG01)the Huanggang Young Talent+2 种基金China(Grant No.HRZF2022-5)the Pearl Scholars Research Programs(Grant Nos.P20190218,P20190219)Young Scholars Start-up Research Programs of Huanggang Normal University,China(Grant Nos.Y20190218,Y20190219)。
文摘Argyrodites,Li_(6)PS_(5)X(X=Cl,Br,I),have piqued the interest of researchers by offering promising lithium ionic conductivity for their application in all-solid-state batteries(ASSBs).However,other than Li_(6)PS_(5)Cl(651Cl)and Li_(6)PS_(5)Br(651Br),Li_(6)PS_(5)I(651I)shows poor ionic conductivity(10^(-7)S cm^(-1)at 298 K).Herein,we present Al-doped 651I with I^(-)/S^(2-)site disordering to lower activation energy(Ea)and improve ionic conductivity.They formed argyrodite-type solid solutions with a composition of(Li_(6–3x)Al_(x))PS_(5)I in 0≤x≤0.10,and structural analysis revealed that Al^(3+)is located at Li sites.Also,the Al-doped samples contained anion I^(-)/S^(2-)site disorders in the crystal structures and smaller lattice parameters than the non-doped samples.Impedance spectroscopy measurements indicated that Al-doping reduced the ionic diffusion barrier,Ea,and increased the ionic conductivity to 10^(-5)S cm^(-1);the(Li5.7Al0.1)PS5I had the highest ionic conductivity in the studied system,at 2.6×10^(-5)S cm^(-1).In a lab-scale ASSB,with(Li_(5.7)Al_(0.1))PS_(5)I functioned as a solid electrolyte,demonstrating the characteristics of a pure ionic conductor with negligible electronic conductivity.The evaluated ionic conduction is due to decreased Li+content and I^(-)/S^(2-)disorder formation.Li-site cation doping enables an in-depth understanding of the structure and provides an additional approach to designing betterperforming SEs in the argyrodite system.
