SECONDARY BATTERY

A secondary battery includes an outer package member, a battery device, and a heat-resistant member. The battery device is contained inside the outer package member. The heat-resistant member has an insulating property and is disposed between the outer package member and the battery device. The outer package member includes a container member and a closing member. The container member has an opening, and contains the battery device inside. The closing member closes the opening, and is welded to the container member. The battery device has an opposed surface and a side surface. The opposed surface is opposed to the closing member. The side surface is coupled to the opposed surface. The heat-resistant member covers from the opposed surface to the side surface.