Secondary battery and its manufacturing method

• Main Author: INAGAKI NAOKO,AKASHI HIROYUKI
• Format: Patent
• Language: English
• Published: 18.07.2007
• Subjects: AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F,C08G; BASIC ELECTRIC ELEMENTS; CHEMISTRY; COMPOSITIONS BASED THEREON; ELECTRICITY; GENERAL PROCESSES OF COMPOUNDING; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY; THEIR PREPARATION OR CHEMICAL WORKING-UP; WORKING-UP

Provided are a secondary battery comprising a separator material capable of achieving a secondary battery with superior high temperature cycle characteristics and a higher energy density, and a method of manufacturing a secondary battery. A separator is evaluated and selected by thermal decomposition gas chromatography (thermal decomposition+GC/MS). In a suitable separator, the value of (the area of Peak 1 exhibiting 1-Decene)/(the area of Peak 2 exhibiting 1-Octene) in a total ion chromatogram (TIC) of the pyrolysate of the separator is 2.05 or less. More preferably, a material in which the value of (the area of Peak 1)/(the area of Peak 2) is 2.00 or less, the value of (the area of Peak 1)/(the area of Peak 3 exhibiting 1-Nonene) is 1.87 or less, and the value of (the area of Peak 3)/(the area of Peak 2) is 1.05 or less is selected, and is used as a separator.