A battery includes a shell, a core and a protection component received in the shell. The core includes a first electrode tab connected to a first current collector and a second electrode tab connected to a second current collector of the core. The protection component includes two insulating layers and a conducting layer disposed between two insulating layers. The conducting layer defines a first end electrically connected to the first electrode tab and a second end configured as a free end, and an outmost current collector of the core is configured by the second current collector.