Patent ID: 7978457

Claim:
An all-solid-state electric double layer capacitor comprising a solid electrolyte and a current collector, wherein the solid electrolyte is an inorganic solid electrolyte, the inorganic solid electrolyte comprises at least one kind of compound selected from the group consisting of a Li-ion conductive compound and a Na-ion conductive compound, the Li-ion conductive compound is at least one kind of a compound selected from the group consisting of a phosphate compound represented by the general formula: Li 1+X M 1 x Ti 2−X (PO 4 ) 3 (where M 1 represents at least one kind of metal selected from the group consisting of Al, Y, Ga, In and La, and X satisfies the following relation: 0≦X≦0.6), an oxide represented by the general formula: (Li 0.39 La 0.54 ) 1−Y/2 M 2 y Ti 1−Y O 3 (where M 2 represents at least one kind of metal selected from the group consisting of Al and Cr, and Y satisfies the following relation: 0≦Y≦0.06), and an oxide represented by the general formula (Li 0.05 La 0.5 )Ti 1−Z M 3 z O 3 , (where M 3 represents at least one kind of metal selected from the group consisting of Ge, Sn, Mn and Zr, and Z satisfies the following relation: 0≦Z≦1), the Na-ion conductive compound is at least one kind of a compound selected from the group consisting of an oxide represented by the general formula: Na 1+γ Zr 2−β Y β P 3−γ Si γ O 12 (where y satisfies the following relation: 0≦γ≦3, and β satisfies the following relation: 0≦β≦2) and a phosphate compound represented by the general formula: Na 1+α M 4 α M 5 2−α (PO 4 ) 3 (where M 4 represents at least one kind of metal selected from Al and In, M 5 represents at least one kind of metal selected from the group consisting of Ge, Sn, Ti, Zr and Hf, and a satisfies the following relation: 0≦α≦2).