Method for producing sulfide glass or sulfide glass ceramic capable of conducing lithium ion, and whole solid type cell using said glass ceramic
The present invention relates to a process for producing sulfide glass or sulfide glass ceramic each capable of conducting a lithium ion, comprising subjecting metallic lithium, sulfur as a simple substance and phosphorus as a simple substance as starting raw materials, which constitute the sulfide glass and sulfide glass ceramic, to mechanical milling to thereby convert them into sulfide glass or sulfide glass ceramic; and a whole solid type cell using the above-mentioned sulfide glass ceramic as a solid electrolyte. According to the present invention, it is made possible to produce sulfide glass and sulfide glass ceramic which are each capable of conducting a lithium ion and which have high electroconductivity at room temperature by a simple and advantageous process from starting raw materials being easily available and inexpensive.
1 . A process for producing sulfide glass or sulfide glass ceramic each capable of conducting a lithium ion, comprising subjecting metallic lithium, sulfur as a simple substance and phosphorus as a simple substance as starting raw materials, which constitute said sulfide glass and sulfide glass ceramic, to mechanical milling to thereby convert them into sulfide glass or sulfide glass ceramic.
2 . The process for producing sulfide glass or sulfide glass ceramic each capable of conducting a lithium ion according to claim 1 , wherein the simple element further comprises at least one element selected from the group consisting of metallic germanium, metallic aluminum, metallic iron, metallic zinc, silicon as a simple substance and boron as a simple substance.
3 . The process for producing sulfide glass or sulfide glass ceramic each capable of conducting a lithium ion according to claim 1 , wherein the metallic lithium is replaced in part or in whole with lithium sulfide.
4 . The process for producing sulfide glass ceramic capable of conducting a lithium ion according to claim 1 , wherein the sulfide glass which has been vitrified by the above-stated mechanical milling is calcined at the glass transition temperature thereof or higher.
5 . The process for producing sulfide glass ceramic capable of conducting a lithium ion according to claim 4 , wherein the above-stated sulfide glass is calcined at 150° C. or higher.
6 . The process for producing sulfide glass ceramic capable of conducting a lithium ion according to claim 4 , wherein the above-stated sulfide glass is calcined under vacuum or in the presence of an inert gas.
7 . The process for producing sulfide glass or sulfide glass ceramic each capable of conducting a lithium ion according to claim 1 , wherein the decomposition voltage of any of the above-stated sulfide glass and sulfide glass ceramic is at least 3 V.
8 . A whole solid type cell which comprises using, as a solid electrolyte, the sulfide glass or sulfide glass ceramic each being produced by the process as set forth in claim 1.