Preparation And Properties Of Solid Electrolyte With Element Se

Solid electrolyte materials, used in all-solid-state batteries, demonstrate excellent thermal stability in contrast to liquid electrolytes, and thus is the most effective ways to solve the safety issue for large-scale batteries. However, the low ionic conductivity of current solid electrolytes seriously limits the application of all-solid-state batteries. Optimization of the components is one of the most effective ways to improve the ionic conductivity. For example, Ge-doped Li3.25Ge0.25P0.75S4 and Li10GeP2S12 show a significantly enhanced ionic conductivity compared with the pristine Li3PS4. Moreover, the optimization of preparation technology is also essential.The activation energy would be reduced by lattice distortion in an optimized content. The cation with lower value doping works best at charge compensation of phosphorus, which would be able to increase the carrier concentration of the ionic conduction system. The doping with anion of larger radius is conducive to enlarge crystal lattice size and broaden transport channel. From the above consideration, both cation and anion doping were applied to this work. Based on Li10GeP2S12, Li10Ge1-zSnzP2S12-2zSe2 z and Li10Ge1-xAlx P2S12-2x Se1.5x were prepared with high ionic conductivity for electrochemical tests. Furthermore, the ionic conductivity of double-doped Li10Ge1-zSnzP2S12-2zSe2 z is better than that of mono-doped Li10GeP2S12-2xSe2 x and Li10Ge1-ySnyP2S12.In addition, sodium-ion conductors in solid-state have been attracted quite a bit of attention because of the cost consideration and the limit source of lithium. At present, Na3PS4 type conductors are one of the most extensively studied solid electrolyte system. In this work, Na3PSe4 were prepared thtough the replacement of Se2- with larger radius to S2- because of the larger ion radius of sodium ions compared to lithium ions. Cubic Na3PSe4 phase was synthesized successfully by elemental starting materials. The results show that Se substitution on S sites expand the lattice, and Na3PSe4 remained cubic structure with high ionic conductivity over 1 mS cm-1 after ball-milling treatment. To the best of our knowledge, this is one of the best values among chalcogenide sodium ion conductors to date.