Normal pressure synthesis of sulfide solid electrolyte composition for the solid lithium secondary batteries

摘要

The present invention relates to a sulfide solid electrolyte for a solid lithium battery and a normal pressure composing method for a solid electrolyte. According to the present invention, the normal pressure composing method for a solid electrolyte includes: a step of preparing each sample containing lithium (Li), germanium (Ge), phosphorus (P), and sulfur (S); and a step of forming a lithium germanium phosphorus sulfide (LGPS) solid electrolyte by composing the samples at normal pressure by heat treatment under atmosphere of inert gas composed of argon (Ar), nitrogen (N_2), or helium (He). The sulfide solid electrolyte for a solid lithium battery can solve a weakness of a vacuum decompression condition process using an existing vacuum tube by composing the LGPS solid electrolyte indicating the highest ion conduction among the solid electrolytes under the atmosphere of the inert gas at normal pressure. Also, the same LGPS solid electrolyte can be obtained as that of the vacuum decompression process. Moreover, a vacuum tube formed of quartz is not used and is not heated to a high temperature to be sealed. Therefore, the samples are prevented from being damaged, and the costs of the process can be reduced since the vacuum tube, which is a consumable supply, is not used.