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All-solid-state lithium batteries (ASSLBs) are promising for safety and high-energy-density large-scale energy storage. In this contribution, we propose a Li3−4xZrxPS4 (LZPS) by Zr-doped β-Li3PS4 (LPS) as a novel solid electrolyte (SE) for ASSLBs based on experimental and simulation methods. The structure, electronic property, mechanical property, and ionic transport properties of LZPS (x = 0, 0.03, 0.06, and 0.1) are investigated with first-principles calculations. Meanwhile, LZPS is prepared by solid states reaction method. By combining experimental analysis and first-principles calculations, it is confirmed that a small amount of Zr4+ can be successfully doped into the framework of β-LPS composites without significantly compromising structural integrity. When the Zr4+ concentration is x = 0.03, the doped material Li2.88Zr0.03PS4 exhibits the highest ionic conductivity (5.1 × 10−4 S·cm−1) at 30 °C, and the Li-ion migration energy barrier is the lowest. The Li2.88Zr0.03PS4 SE has obtained the best mechanical properties, the good ductility, and shear deformation resistance, which can better maintain the structural stability of the battery. In addition, the Li/Li symmetrical cell is assembled, which shows excellent electrochemical stability of electrolyte against lithium. The constructed all-solid-state batteries (LiCoO2-Li6PS5Cl|Li2.88Zr0.03PS4|Li-In) delivers an initial discharge capacity of 130.4 mAh·g−1 at 0.2 C and a capacity retention of 85.1% after 100 cycles at room temperature. This study provides a promising electrolyte for the application of ASSLBs with high ionic conductivity and excellent stability against lithium. [ABSTRACT FROM AUTHOR]

The mechanical strength and ionic conductivity of sulfide solid electrolytes have received widespread attention for their application in solid sodium batteries. Herein, first-principles calculations are used to determine the properties, including the electronic, mechanical and ionic transport properties, of Na3PS4 sulfide solid electrolytes doped with low and high Ca ion concentrations. Our theoretical results demonstrate that low Ca ion concentrations can be easily doped in tetragonal and cubic phases (t-Na3PS4 and c-Na3PS4) and create a suitable number of Na vacancies based on the formation energy analysis. Furthermore, the calculated density of states and charge density differences indicate that the surrounding electronic environment is changed, and Ca–S ionic bonds are formed in Na3PS4 with Ca-doping. In addition, the improved ductility and mechanical strength of c-Na3PS4 and t-Na3PS4 achieved by low-concentration Ca doping may help suppress dendritic growth and electrode deformation. Finally, sodium ion migration in Ca-doped Na3PS4 is described with the aid of the CI-NEB method, and it is found that the migration energy barriers are less than those of pure Na3PS4, which suggests that the sodium ion conductivity can be effectively improved by doping with low Ca2+ concentrations. The present work improves the understanding of the influence of doping on the performance of solid electrolytes and provides a feasible framework for the future design of high-performance solid electrodes. [ABSTRACT FROM AUTHOR]