Abstract: An over-current protection device includes first and second electrode layers and a PTC material layer laminated therebetween. The PTC material layer includes a polymer matrix, a conductive filler, and a titanium-containing dielectric filler. The polymer matrix has a fluoropolymer. The titanium-containing dielectric filler has a compound represented by a general formula of MTiO3, wherein the M represents transition metal or alkaline earth metal. The total volume of the PTC material layer is calculated as 100%, and the titanium-containing dielectric filler accounts to for 5-15% by volume of the PTC material layer.

Abstract: A lithium ion battery includes a negative electrode, a positive electrode, an separator between the electrodes, and electrolyte for submerging the electrodes. The negative electrode is made of active materials including at least one lowly graphitized carbon material and least one highly graphitized carbon material. The positive electrode made of active materials including lithium ion, transition metal ion and polyanion. The polyanion is selected from the group consisting of phosphate, silicate, sulfate and hydrofluoric acid. The transition metal ion is selected from the group consisting of the divalent ions of iron and manganese.

Abstract: The present invention is to provide a lithium battery can be exempted from short circuit problems caused by metallic particles agitated through the manufacturing process and later usage. Said lithium battery includes a battery cover, anode films, separators, cathode films, an organic electrolyte, a cylindrical housing with a neck portion formed on an upper portion of the cylindrical housing. Said neck portion is spread with a layer of polymeric based composite materials onto an inner wall inside the neck portion, damages happened to the neck portion will not cause short circuit also.