Method for modifying cathode material and lithium battery employing the cathode material

A lithium battery, comprising

• a cathode plate and an anode plate;
• a separator disposed between the cathode plate and the anode plate to define a reservoir region;
• and
• an electrolyte filled in the reservoir region,
• wherein a thermal protective film is provided to cover a material of the cathode plate or the anode plate, and when a battery temperature rises over an onset temperature of the thermal protective film, the thermal protective film undergoes a crosslinking reaction to inhibit thermal runaway, thereby preventing combustion or an explosion of the lithium battery, wherein the onset temperature is between about 80° C. and 280° C.