Patent ID: 7368203

Claim:
A non-aqueous electrolyte secondary cell comprising: a positive electrode having a positive electrode active material intercalating and deintercalating lithium ions; a negative electrode having a negative electrode active material intercalating and deintercalating lithium ions; a non-aqueous electrolyte having a non-aqueous solvent and an electrolyte salt; an outer casing can having mounted therein the positive electrode, the negative electrode, and the non-aqueous electrolyte, and having an opening portion; and a sealing structure for sealing the opening portion and having a sealing plate; wherein: the positive electrode active material consists of a lithium cobalt oxide; the positive electrode active material has a bulk density in the positive electrode of 3.3 g/cm 3 or more; and the non-aqueous electrolyte includes a vinylene carbonate compound represented by Chemical Formula 1, a cyclic sulfite compound represented by Chemical Formula 2 or 3, and a phenylcycloalkane compound, where R1 and R2 are independently a hydrogen atom or an alkyl group with two carbons or less, where R1 to R4 are independently a hydrogen atom or an alkyl group with two carbons or less, where R1 and R2 are independently a hydrogen atom or an alkyl group with two carbons or less.