An explosion-proof lithium ion battery

The invention provides an explosion-proof lithium ion battery, which comprises a housing, an electrode assembly, an electrolyte, a cover plate assembly, wherein the electrode assembly comprises a positive electrode, a negative electrode, a separator positioned between the positive electrode and the negative electrode, and a mandrel; The mandrel is inserted into the center of the electrode assemblyto support the shape of the electrode assembly. The mandrel is a hollow tube, and an electromagnetic element and a pierce element are arranged in the hollow tube; The piercing element is made of magnetic material, which is arranged in the hollow tube of the mandrel and opposite to the cover plate assembly. The battery is in an abnormal condition, the pierce element is driven to move relative to the pressure relief plate within the hollow tube by an electromagnetic element. The battery makes full use of the existing mandrel to build an explosion-proof device to improve the safety of lithium battery, through the sensor