POSITIVE ELECTRODE PASTE FOR NONAQUEOUS SECONDARY BATTERY, POSITIVE ELECTRODE FOR NONAQUEOUS SECONDARY BATTERY, AND NONAQUEOUS SECONDARY BATTERY

• Main Authors: TSUJITA KOHEI, ANAMI KEISUKE, KUWABARA KAZUO
• Format: Patent
• Language: English; Japanese
• Published: 16.04.2015
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRICITY; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY

PROBLEM TO BE SOLVED: To provide a positive electrode paste for a nonaqueous secondary battery, low in initial viscosity and sufficiently suppressed in an increase of viscosity during storage.SOLUTION: A dispersion material of a positive electrode paste is a copolymer comprising a constitutional unit (a) including 2-ethyl hexyl methacrylate or the like, a constitutional unit (b) including 2-hydroxyethyl methacrylate, methoxy polyethylene glycol methacrylate or the like, and a constitutional unit (c), and has an acid dissociation constant pKa of 5.0 or less in water after the constitutional unit (c) is polymerized. The constitutional unit (c) includes an acid group of one of carboxylic acid, phosphoric acid and sulfonic acid. 【課題】初期粘度が低く、保管時の粘度増大が十分に抑制される、非水系二次電池用正極ペーストを提供する。【解決手段】正極ペーストの分散材が、２−エチルヘキシル（メタ）アクリレート等を構成単位とする（ａ）、２−ヒドロキシエチル（メタ）アクリレート、メトキシポリエチレングリコール（メタ）アクリレート等を構成単位とする（ｂ）及び構成単位（ｃ）からなる共重合体であり、前記構成単位（ｃ）の重合後の水中での酸解離定数pKaが5.0以下とする。前記構成単位（ｃ）はカルボン酸、リン酸、スルホン酸のいずれかの酸性基を含む。【選択図】なし