POROUS POLYIMIDE FILM, SEPARATOR FOR LITHIUM ION SECONDARY BATTERY, LITHIUM ION SECONDARY BATTERY, AND ALL SOLID STATE BATTERY

• Main Authors: KAJIMA YASUNOBU, SUGAWARA HIROSHI, HIROSE EIICHI, YOSHIMURA KOSAKU
• Format: Patent
• Language: English; Japanese
• Published: 13.08.2020
• 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

To provide a porous polyimide film that can suppress a decrease of battery capacity due to repeated charging/discharging when a secondary battery is used.SOLUTION: In a pore distribution measured by a mercury press-in method, a pore distribution width represented by a square root ((D/D)) of a ratio of a pore diameter Dwhen cumulated from a small diameter side becomes 84% relative to a pore diameter Dwhen cumulated pores from a small diameter side becomes 16%, by volume standard is 1.15 or smaller, a pore diameter in the range of 0.50 μm or larger and 3.0 μm or smaller, an air permeation rate is 30 seconds or smaller.SELECTED DRAWING: None 【課題】二次電池に適用したときの繰り返し充放電による電池容量の低下が抑制される多孔質ポリイミド膜の提供。【解決手段】水銀圧入法によって測定される細孔分布において、体積基準で、細孔の小径側から累積した１６％になるときの細孔径Ｄ１６に対する小径側から累積した８４％になるときの細孔径Ｄ８４の割合の平方根（（Ｄ８４／Ｄ１６）１／２）で表される細孔分布幅が１．１５以下であり、空孔径が０．５０μｍ以上３．０μｍ以下であり、透気速度が３０秒以下である多孔質ポリイミド膜。【選択図】なし