Electrode assembly and three-electrode battery

The invention discloses an electrode assembly and a three-electrode battery, and relates to the technical field of batteries, the electrode assembly comprises a battery cell, the battery cell comprises a first pole piece, a second pole piece and a diaphragm assembly, and the diaphragm assembly is located between the first pole piece and the second pole piece; the reference electrode comprises an activation part, the activation part is located in the diaphragm assembly, and the activation part is opposite to the central area of the largest surface of the battery cell in the thickness direction of the battery cell. According to the three-electrode battery disclosed by the invention, the activation part is opposite to the central region of the maximum surface of the battery cell in the thickness direction of the battery cell, so that the position of the activation part in the battery cell is limited, the chemical environment in which the activation part is located is more stable, and the electrode potential fluc