Patent ID: 8017268

Claim:
A lithium secondary battery comprising: a battery body having a positive electrode and a negative electrode; and a discharge unit connected in parallel with the positive and negative electrodes, the discharge unit comprising: a first electrode connected to one of the positive electrode and the negative electrode of the battery body; a second electrode connected to the other of the positive electrode and the negative electrode of the battery body; and a discharge material film, connected between the first electrode and the second electrode, inducing a abrupt discharge above a predetermined temperature, wherein the first and second electrodes have comb-like structures with a plurality of recesses and protrusions such that the first electrode is engaged with the second electrode, and wherein the comb-like structures of the first and second electrodes cover a portion of the discharge material film, wherein the discharge material film is a abrupt metal-insulator transition material film having a transition resistance difference (ΔR) of 10 3 to 10 5 Ω, and a metal-phase resistance of 500Ω or less.