SECONDARY BATTERY AND BATTERY MODULE

The present disclosure provides a secondary battery and a battery module. The secondary battery includes an electrode assembly, a case and a cap assembly. The case includes an accommodating cavity, and the electrode assembly is accommodated in the accommodating cavity. The electrode assembly includes electrode units, which are stacked in an axial direction of the accommodating cavity. The cap assembly includes a cap plate and an insulating member disposed on an inner side of the cap plate. The cap plate is connected to the case, and the insulating member is located on a side of the electrode assembly in the axial direction. The insulating member is provided with a first surface at a side close to the electrode assembly, and the first surface is a flat surface. A battery module includes second batteries, which are arranged sequentially and an arrangement direction of which is perpendicular to the axial direction.