SOLID ELECTROLYTE AND SOLID ELECTROLYTE BATTERY

A solid electrolyte is composed of a compound represented by the following formula. AEGX(A is at least one element selected from Li and Cs. E is at least one element selected from the group consisting of Al, Sc, Y, Zr, Hf and lanthanoids. G is at least one group selected from the group consisting of OH, BO, BO, BO, BO, BO, CO, NO, AlO, SiO, SiO, SiO, SiO, SiO, SiO, PO, PO, PO, PO, SO, SO, SO, SO, SO, SO, SO, SO, SO, BF, PFand BOB. X is at least one element selected from the group consisting of F, Cl, Br and I. 0.5≤a