A new class of sulfide electrolytes, (1-x)LiCl-xLiBr-2Li₃PS₄ (x = 0, 0.25, 0.50, 0.75, and 1.0), was synthesized, and characterized their stable temperature range, ionic-conductivity and applicability for all-solid-state lithium metal battery. The optimal heat-treatment temperature of the synthesis process is relatively low, i.e., 200 °C. Ionic conductivity of the electrolyte increases with increasing LiBr ratio, and maximum ionic conductivity at 25 °C is 1.7 mScm⁻¹ with x = 0.75. At higher heat-treatment temperature, above 250 °C, a low-ionic-conduction crystalline phase appears in the electrolyte, and at that time, ionic conductivity decreases to a similar value to that of the amorphous precursor used in the synthesis process. Since the electrolyte does not contain a transition metal, it is applicable to the lithium-metal secondary system. A reversible lithium deposition-stripping reaction was demonstrated by cyclic voltammogram, the results of which indicate that the electrolyte is applicable to a typical 4-V rechargeable lithium-metal secondary system. The Coulombic efficiency of the first charge-discharge cycle is approximately 75%, and reversible capacity of 185 mAhg⁻¹ was verified by a Li/0.25LiCl-0.75LiBr-2Li₃PS₄/NCA pelletized-cell test. It is concluded from these results that the proposed low-temperature-synthesized sulfide electrolytes will reduce energy consumption for material production, and such a low-carbon-footprint process meets the demand of the future sustainable society.

合成了一类新的硫化物电解质 (1-x)LiCl-xLiBr-2Li ₃ PS ₄ (x = 0, 0.25, 0.50, 0.75, and 1.0)，并表征了它们的稳定温度范围、离子电导率和适用性用于全固态锂金属电池。合成过程的最佳热处理温度较低，即200℃。电解质的离子电导率随着 LiBr 比例的增加而增加，25 °C 时的最大离子电导率为 1.7 mScm ^-1x = 0.75。在较高的热处理温度，高于 250 °C 时，电解质中出现低离子电导的结晶相，此时，离子电导率降低到与合成过程中使用的无定形前体相似的值。由于电解液不含过渡金属，因此适用于锂金属二次体系。通过循环伏安图证明了可逆的锂沉积-剥离反应，结果表明该电解质适用于典型的 4 V 可充电锂金属二次系统。第一次充放电循环的库仑效率约为75%，通过Li/0.25LiCl-0.75LiBr-2Li ₃ PS _{4验证了185 mAhg} ^{-1的可逆容量}/NCA 颗粒细胞测试。从这些结果可以得出结论，所提出的低温合成硫化物电解质将降低材料生产的能源消耗，这种低碳足迹的工艺满足未来可持续社会的需求。