Electrode active substance, method for producing electrode active substance, and all-solid battery using electrode active substance

Abstract

A negative electrode active substance is used for a negative electrode layer of an all-solid battery and contains a plurality of secondary particles. The plurality of secondary particles contain impregnated particles which are secondary particles having a polymer solid electrolyte region impregnated with the polymer solid electrolyte therein and an active material region.

What is claimed is: 
     
         1 . An electrode active substance used for a positive electrode or a negative electrode of an all-solid battery, the electrode active substance comprising a plurality of secondary particles, wherein
 the plurality of secondary particles contain impregnated particles which are secondary particles having a polymer solid electrolyte region impregnated with a polymer solid electrolyte therein and an active material region.   
     
     
         2 . The electrode active substance according to  claim 1 , wherein a ratio of a volume of the polymer solid electrolyte region to a volume of the plurality of secondary particles is 1% to 3%. 
     
     
         3 . The electrode active substance according to  claim 1 , wherein
 a ratio of the volume of the polymer solid electrolyte region to a volume of the impregnated particles is 6.0% to 10.5%.   
     
     
         4 . The electrode active substance according to  claim 1 , wherein
 the impregnated particles further have voids therein.   
     
     
         5 . The electrode active substance according to  claim 4 , wherein
 a ratio of a volume of the voids to the volume of the impregnated particles is 0.5% to 1.0%.   
     
     
         6 . An all-solid battery, comprising:
 a positive electrode or a negative electrode using the electrode active substance according to  claim 1 .   
     
     
         7 . A method for producing an electrode active substance used for a positive electrode or a negative electrode of an all-solid battery, the method comprising:
 preparing an electrode active substance material containing a plurality of secondary particles each of which has voids therein and a polymer solid electrolyte;   dissolving or dispersing the polymer solid electrolyte in a supercritical fluid to form a supercritical fluid mixture;   bringing the electrode active substance material into contact with the supercritical fluid mixture; and   cooling and depressurizing the supercritical fluid mixture.   
     
     
         8 . The method for producing an electrode active substance according to  claim 7 , wherein
 the supercritical fluid is supercritical carbon dioxide or supercritical water.   
     
     
         9 . The method for producing an electrode active substance according to  claim 7 , wherein
 the supercritical fluid mixture is formed by adding a solvent having compatibility with the polymer solid electrolyte to the supercritical fluid.