The invention discloses a cylindrical
lithium battery with a protective function and aims to improve the using safety and reduce the using cost of the
lithium battery. The cylindrical
lithium battery comprises a cylindrical single
lithium battery, a circular protective circuit board, a circular insulating
gasket, an
anode battery cap and a heat-shrinkable tubing, wherein the
diameter of the circular protective circuit board is the same as that of the cylindrical single
lithium battery; a piece is arranged on one surface of the circular protective circuit board, and the other surface of the circular protective circuit board adopts a
cathode output end; at least one of a short-
circuit protection circuit, an
overcharge protection circuit, an over
discharge protection circuit and an
overcurrent protection circuit is arranged on the circular protective circuit board; the circular protective circuit board is connected with the
anode and the
cathode of the cylindrical single
lithium battery through a
nickel strap; the circular insulating
gasket is arranged between one side of the circular insulating
gasket, on which the piece is arranged, and the
cathode end face of the cylindrical single lithium battery; the
anode battery cap is arranged on the anode end face of the cylindrical single lithium battery in a
spot welding manner; the circular insulating gasket is mounted on the anode battery cap; the external of the complete battery is packaged by the heat-shrinkable tubing. According to the invention, as the protection circuits are added, the using safety is improved.