All-solid-state batteries are considered as nextgeneration technology for energy storage due to their high energy density and excellent s afety.However,only a few solid electrolytes exhibit ionic conductivities compar...All-solid-state batteries are considered as nextgeneration technology for energy storage due to their high energy density and excellent s afety.However,only a few solid electrolytes exhibit ionic conductivities comparable to liquid electrolytes.Finding low-cost solid electrolytes with high Liion conductivity is in high demand.Based on the ab initio molecular dynamic simulations,the Li^(+)diffusion inβ-LiAISi_(2)O_(6),a type of cost-effective and naturally-available mineral,and its disordered systems Li_(1-x)Al_(1-x)Si_(2+x)O_(6)with-1.0≤x≤0.5 was studied.Our calculations show that the phases of Li_(1-x)Al_(1-x)Si_(2+x)O_(6)with nonzero x all possess much lower diffusion energy barriers than pristine LiAlSi_(2)O_(6).When x is positive,increased concentration of lithium vacancies accelerates the diffusion of Li-ions.When x is negative,additional Li-ions are inserted into structures and co-migration is stimulated among these Li-ions.In particular,the maximal ionic conductivity at 300 K(1.92×10^(-6)S·cm^(-1))is obtained in Li_(2)Al_(2)SiO_(6)(x=-1.0),which is five orders of magnitude larger than that of pristineβ-LiAlSi_(2)O_(6).In addition,the diffusion barrier can be further reduced to 0.38 eV by replacing Si with Ge,and the ionic conductivity for Li_(2)Al_(2)GeO_(6)can reach 3.08×10~(-5)S·cm^(-1)at 300 K.Our work facilitates the understanding of Li+conduction mechanisms in silicatebased electrolytes and the development of cost-effective and high-performance solid-s ate electrolytes.展开更多
基金financially supported by the National Natural Science foundation of China(Nos.51972043 and 52102212)Sichuan-Hong Kong Collaborative Research Fund(No.2021YFH0184)+1 种基金Sichuan Natural Science Fund(Nos.23NSFSC0411 and 23NSFSC3618)the Foundation of Yangtze Delta Region Institute(Huzhou)of UESTC,China(Nos.U03210010 and U03210028)。
文摘All-solid-state batteries are considered as nextgeneration technology for energy storage due to their high energy density and excellent s afety.However,only a few solid electrolytes exhibit ionic conductivities comparable to liquid electrolytes.Finding low-cost solid electrolytes with high Liion conductivity is in high demand.Based on the ab initio molecular dynamic simulations,the Li^(+)diffusion inβ-LiAISi_(2)O_(6),a type of cost-effective and naturally-available mineral,and its disordered systems Li_(1-x)Al_(1-x)Si_(2+x)O_(6)with-1.0≤x≤0.5 was studied.Our calculations show that the phases of Li_(1-x)Al_(1-x)Si_(2+x)O_(6)with nonzero x all possess much lower diffusion energy barriers than pristine LiAlSi_(2)O_(6).When x is positive,increased concentration of lithium vacancies accelerates the diffusion of Li-ions.When x is negative,additional Li-ions are inserted into structures and co-migration is stimulated among these Li-ions.In particular,the maximal ionic conductivity at 300 K(1.92×10^(-6)S·cm^(-1))is obtained in Li_(2)Al_(2)SiO_(6)(x=-1.0),which is five orders of magnitude larger than that of pristineβ-LiAlSi_(2)O_(6).In addition,the diffusion barrier can be further reduced to 0.38 eV by replacing Si with Ge,and the ionic conductivity for Li_(2)Al_(2)GeO_(6)can reach 3.08×10~(-5)S·cm^(-1)at 300 K.Our work facilitates the understanding of Li+conduction mechanisms in silicatebased electrolytes and the development of cost-effective and high-performance solid-s ate electrolytes.
