All-solid secondary battery

An all-solid secondary battery comprising:

• a cathode layer;
• an anode layer;
• a first solid electrolyte layer between the cathode layer and the anode layer and adjacent to the cathode layer;
• and
• a second solid electrolyte layer between the cathode layer and the anode layer and adjacent to the anode layer,
• wherein the cathode layer comprises a cathode current collector and a cathode active material layer on the cathode current collector,
• the anode layer comprises an anode current collector and a first anode active material layer or a third anode active material layer on the anode current collector, and
• a composite structure is between the first solid electrolyte layer and the second solid electrolyte layer, and
• wherein the composite structure comprises:
• a composite solid electrolyte that is on a central portion of the second solid electrolyte layer and comprises an ion conductor and a lithium salt;
• and
• an insulating member that is on peripheral portions of the second solid electrolyte layer and is around one or more outer surfaces of the composite solid electrolyte.