The garnet-type Li_(7)La_(3)Zr_(2)O_(12)(LLZO)solid electrolyte is regarded as a promising option for all-solid-state batteries owing to its notable features,including high ionic conductivity and wide electrochemical ...The garnet-type Li_(7)La_(3)Zr_(2)O_(12)(LLZO)solid electrolyte is regarded as a promising option for all-solid-state batteries owing to its notable features,including high ionic conductivity and wide electrochemical window.Although aluminum-doped LLZO(Al-LLZO)is crucial for achieving LLZO ceramics with high critical current density,the characteristics of its grain and grain boundary structures remain largely elusive.In this work,the electrochemical impedance spectroscopy(EIS)technique,in conjunction with the distribution of relaxation times(DRT)method,was employed to investigate structural alterations in Al-LLZO ceramics modified by La_(2)Zr_(2)O_(7)(LZO)additives.Additionally,the impact of sintering temperature and electrolyte testing temperature on ceramic structural changes was investigated using the DRT tools.By optimizing experimental conditions such as the concentration of added LZO and the sintering temperature of Al-LLZO,the study was further refined.This enabled us to successfully identify Al-LLZO solid electrolytes exhibiting uniform morphological structures,moderate crystal grain sizes and high density.By adding 6 wt%of LZO to the Al-LLZO solid electrolyte,we achieved the purest cubic phase and optimal lithium-ion conductivity.Under this condition,the sintered Al-LLZO ceramics exhibited exceeding 4.2×10^(-4)S·cm^(-1)conductivity at room temperature and a high critical current density of up to 0.6 mA·cm^(-2).展开更多
基金supported by the National Natural Science Foundation of China(No.52102284)the Science and Technology Project of Shenzhen(Nos.JCYJ20210324094206019 and JCYJ20210324094000001).
文摘The garnet-type Li_(7)La_(3)Zr_(2)O_(12)(LLZO)solid electrolyte is regarded as a promising option for all-solid-state batteries owing to its notable features,including high ionic conductivity and wide electrochemical window.Although aluminum-doped LLZO(Al-LLZO)is crucial for achieving LLZO ceramics with high critical current density,the characteristics of its grain and grain boundary structures remain largely elusive.In this work,the electrochemical impedance spectroscopy(EIS)technique,in conjunction with the distribution of relaxation times(DRT)method,was employed to investigate structural alterations in Al-LLZO ceramics modified by La_(2)Zr_(2)O_(7)(LZO)additives.Additionally,the impact of sintering temperature and electrolyte testing temperature on ceramic structural changes was investigated using the DRT tools.By optimizing experimental conditions such as the concentration of added LZO and the sintering temperature of Al-LLZO,the study was further refined.This enabled us to successfully identify Al-LLZO solid electrolytes exhibiting uniform morphological structures,moderate crystal grain sizes and high density.By adding 6 wt%of LZO to the Al-LLZO solid electrolyte,we achieved the purest cubic phase and optimal lithium-ion conductivity.Under this condition,the sintered Al-LLZO ceramics exhibited exceeding 4.2×10^(-4)S·cm^(-1)conductivity at room temperature and a high critical current density of up to 0.6 mA·cm^(-2).
