METHOD FOR MANUFACTURING GRAPHITE MATERIAL FOR LITHIUM ION SECONDARY BATTERY, NEGATIVE ELECTRODE FOR LITHIUM ION SECONDARY BATTERY, AND LITHIUM ION SECONDARY BATTERY

• Main Authors: YASUMARU JUNICHI, MATOBA NAOKI, TENNO KOJIRO
• Format: Patent
• Language: English; Japanese
• Published: 19.03.2015
• Subjects: BASIC ELECTRIC ELEMENTS; CHEMISTRY; COMPOUNDS THEREOF; ELECTRICITY; INORGANIC CHEMISTRY; METALLURGY; NON-METALLIC ELEMENTS; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY

PROBLEM TO BE SOLVED: To provide a graphite material for a lithium ion secondary battery having a low specific surface area and excellent in performance such as electrode density, initial efficiency, and load characteristics, and to provide a method for manufacturing the graphite material for the lithium ion secondary battery.SOLUTION: In graphite material for a lithium ion secondary battery, a coating layer comprising carbide is formed on surfaces of pressed graphite particles formed by pressing natural graphite globular particles and/or natural graphite massive particles. A method for manufacturing the graphite material for the lithium ion secondary battery includes: a pressing step for obtaining the pressed graphite particles by pressing the natural graphite globular particles and/or the natural graphite massive particles; and a coating step for coating the obtained pressed graphite particles with a carbon material precursor, then heating it to obtain a carbon coating. 【課題】低い比表面積を有し、電極密度、初期効率、負荷特性などの性能に優れたリチウムイオン二次電池用黒鉛材料、並びに、該リチウムイオン二次電池用黒鉛材料の製造方法を提供することを目的とする。【解決手段】本発明のリチウムイオン二次電池用黒鉛材料は、天然黒鉛球状化粒子および／または天然黒鉛塊状化粒子が加圧処理された加圧黒鉛粒子の表面に炭化物からなる被覆層が形成されていることを特徴とする。本発明のリチウムイオン二次電池用黒鉛材料の製造方法は、天然黒鉛球状化粒子および／または天然黒鉛塊状化粒子を加圧処理して加圧黒鉛粒子を得る加圧工程；得られた加圧黒鉛粒子を炭素物質前駆体により被覆した後、熱処理して炭素被覆する被覆工程を有することを特徴とする。【選択図】図１