SECONDARY BATTERY, BATTERY MODULE AND ELECTRIC VEHICLE

Disclosed are a secondary battery, a battery module and an electric vehicle. The battery module includes a plurality of secondary batteries arranged in sequence. The secondary battery includes an electrode assembly (1), a housing (2) and a top cover assembly (3). The housing (2) has an accommodating chamber (21), the electrode assembly (1) being accommodated in the accommodating chamber (21). The electrode assembly (1) includes a plurality of electrode units (11), the plurality of electrode units (11) being stacked in an axial direction (Z) of the accommodating chamber (21). The top cover assembly (3) includes a top cover plate (31) and an insulating member (32) arranged on an inner side of the top cover plate (31), the top cover plate (31) being connected to the housing (2), and the insulating member (32) being located on a side of the electrode assembly (1) in the axial direction (Z). A first buffer gap (G1) is provided between the insulating member (32) and the top cover plate (31). In the battery module, the arrangement direction of the plurality of secondary batteries is perpendicular to the axial direction (Z).