This invention discloses a PTC safety
coating, its preparation method, and its application, belonging to the field of
lithium-
ion battery technology. The PTC safety
coating comprises, by weight, 30-50 parts of PTC
polymer material, 30-50 parts of
ion conductor, 1-5 parts of conductive agent, 2-15 parts of aqueous binder, 0.1-0.8 parts of dispersant, 0.01-0.1 parts of
wetting agent, and 80-90 parts of water. The PTC safety
coating of this invention includes PTC
polymer material and
ion conductor. The PTC material significantly improves the
thermal stability and
thermal safety performance of the battery; at a certain temperature, its
internal resistance increases significantly, thereby
cutting off the current and suppressing
thermal runaway. The ion conductor increases the
conductivity of the coating, compensates for the poor
conductivity of the PTC material causing
electron transfer impedance and high coating impedance, alleviates
battery room-temperature polarization, reduces
internal resistance loss, and avoids deterioration of cycle performance.