Secondary battery and electronic device

An electronic device, comprising a secondary battery;

• the secondary battery comprises a positive electrode plate and a separator;
• wherein the positive electrode plate comprises a positive current collector and a positive electrode material layer disposed on at least one surface of the positive current collector;
• the positive electrode material layer comprises a first material layer and a second material layer;
• the first material layer is located between the positive current collector and the second material layer;
• a contact surface between the first material layer and the second material layer defines an interface;
• an interface region comprises:
• a region extending 5 μm from the interface along a direction from the first material layer to the second material layer, and a region extending 5 μm from the interface along a direction from the second material layer to the first material layer;
• a region other than the interface region in the first material layer is a first region;
• a region other than the interface region in the second material layer is a second region;
• an average particle diameter of active material particles in the first region is D1, 3 μm≤D1≤5 μm;
• an average particle diameter of active material particles in the second region is D2, 9 μm≤D2≤40 μm;
• an average particle diameter of active material particles in the interface region is D3, 6 μm≤D3≤22 μm;
• and
• the separator comprises a base film and an adhesive layer;
• the adhesive layer is disposed on at least one main surface of the base film in a thickness direction of the base film;
• the adhesive layer is in contact with the second material layer.