COATED POSITIVE ELECTRODE ACTIVE MATERIAL FOR LITHIUM ION BATTERY

• Main Authors: SATO HAJIME, KUSANO RYOSUKE, HORIE HIDEAKI, AKAMA HIROSHI, KUSACHI TAKEKI, OSAWA YASUHIKO
• Format: Patent
• Language: English; Japanese
• Published: 30.08.2018
• 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 coated positive electrode active material for a lithium ion battery, which is superior in cycle characteristics.SOLUTION: A coated positive electrode active material for a lithium ion battery is arranged by coating at least part of the surface of a positive electrode active material for a lithium ion battery with a coating layer containing a coating resin composition and a conducting agent. The coating resin composition contains a chelating polymer compound capturing a transition metal ion or transition metal atom; the coverage determined by the computational expression below is over 30.0%. Coverage (%)={1-[BET specific surface area of the coated positive electrode active material/(BET specific surface area of the positive electrode active material×Weight percentage of the positive electrode active material included in the coated positive electrode active material+BET specific surface area of the conducting agent×Weight percentage of the conducting agent included in the coated positive electrode active material)]}×100.SELECTED DRAWING: None 【課題】サイクル特性に優れるリチウムイオン電池用被覆正極活物質を提供すること。【解決手段】リチウムイオン電池用正極活物質が有する表面の少なくとも一部を被覆樹脂組成物と導電剤とを含む被覆層で被覆してなるリチウムイオン電池用被覆正極活物質であって、上記被覆樹脂組成物は、遷移金属イオン又は遷移金属原子を捕捉するキレート性高分子化合物を含み、下記の計算式で得られる被覆率が３０．０％を超えることを特徴とするリチウムイオン電池用被覆正極活物質。被覆率（％）＝｛１−［被覆正極活物質のＢＥＴ比表面積／（正極活物質のＢＥＴ比表面積×被覆正極活物質中に含まれる正極活物質の重量割合＋導電剤のＢＥＴ比表面積×被覆正極活物質中に含まれる導電剤の重量割合）］｝×１００【選択図】 なし