<p>Herein, Li_7−4xAl_xP_1−xS_6−3x (x = 0, 0.1, 0.2 and 0.3) solid electrolytes were prepared via liquid-phase synthesis. X-ray diffraction (XRD) and scanning electron microscopy with energy-dispersive spectroscopy were employed to characterise the structure of the prepared samples. XRD data refinement confirmed that Al was successfully incorporated into the crystal structure of the low-temperature (LT) phase of argyrodite-type Li₇PS₆. At 25&#xa0;°C, the ionic conductivities for x = 0, 0.1, 0.2 and 0.3 were 2.3 × 10⁻⁵, 1.2 × 10⁻⁴, 7.4 × 10⁻⁵ and 3.2 × 10⁻⁵ S·cm⁻¹, respectively. The ionic conductivity of LT-Li₇PS₆ prepared in this study was enhanced by Al doping and reached 1.2 × 10⁻⁴ S·cm⁻¹ in the sample with x = 0.1. The data from alternating-current electrochemical impedance spectroscopy were analysed to find that the thermally active mechanism of mobile Li⁺ migration was the primary contributor to ionic conduction of the prepared samples.</p>