NOVELTY - Lithium battery comprises cathode plate (1) and anode plate; separator disposed between the cathode plate and anode plate to define a reservoir region; and an electrolyte filled in the reservoir region. A thermal protective film (103) is provided to cover a material of the cathode plate or the anode plate. When a battery temperature rises over an onset temperature of the thermal protective film, the thermal protective film undergoes crosslinking reaction to inhibit thermal runaway, preventing combustion or explosion of lithium battery, where onset temperature is 80-280 degrees C.    USE - Lithium battery i.e. lithium-ion secondary battery. Uses include but are not limited to consumer electronics, computer, communications (3C) products, electric vehicles, light electric vehicles, or large-scale electricity storage systems that demand high safety.    ADVANTAGE - The thermal protective film enables thermal actuation safety mechanism at 80-280 degrees C to inhibit thermal runaway. The nitrogen-containing polymer with thermal triggering function modifies the surface of the electrode material to construct another internal safety mechanism. It can conduct a redox reaction with cathode or anode material to form a unique, nanoporous solid electrolyte interface protective film. By combining these two independent safety mechanisms, synergistic effect is obtained to greatly improve the safety of lithium batteries. The shutdown performance of lithium batteries are drastically improved to prevent excessive heat production due to interior short circuits, thus reducing the risk of battery combustion or explosion. Conventional lithium batteries that use only 1 safety mechanism have sigma -quality level of 6. With 2 safety mechanisms, the lithium batteries having 2 safety mechanisms have sigma quality level of 9, or even 12. The electrode plate made of modified powder forms a unique solid electrolyte interface (SEI) film on the electrode material during battery activation. The SEI film enables thermal actuation mechanism that reduces or prevents the release of oxygen from the fully charged electrode plate (especially a cathode plate) under elevated temperatures. As such, the exothermic reaction between the electrolyte and the electrode plate can be reduced or avoided to assure the safety of the battery, without sacrificing battery life span or other battery performance parameters.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method of fabricating lithium battery comprising providing electrode material (101) powder; modifying the electrode material powder with nitrogen-containing polymer to form modified electrode material powder; forming modified electrode plate comprising the modified electrode material powder, conductive additive, and binder, where nitrogen-containing polymer covers the modified electrode material powder; forming lithium battery comprising the modified electrode plate; and activating the lithium battery by charging operation to form thermal protective film (103) in the modified electrode plate.    DESCRIPTION OF DRAWING(S) - The drawing is a schematic enlarged view of a portion of a modified cathode plate.    Cathode plate (1)    Electrode material (101)    Thermal protective film (103)