PRODUCTION METHOD OF GRAPHITE MATERIAL FOR ELECTRODE MATERIAL OF LITHIUM ION BATTERY

PROBLEM TO BE SOLVED: To provide a high quality graphite material for the electrode material of lithium ion battery, useful for obtaining the negative electrode material for high quality lithium ion secondary battery excellent in stability, with less contamination of impurities.SOLUTION: A production material of graphite material includes a step of graphitizing a carbon material by feeding a current directly and heating up. When a carbon material 1 before graphitization is compressed to have a density of 1.4 g/cm, the value of resistance of consolidation powder is 0.4 Ωcm or less, the repose angle is 20°-50°, D90 in particle size distribution of volume reference measured by laser diffraction method is 120 μm or less, the coefficient of thermal expansion CTE at 30-100°C is 4.0×10/°C-6.0×10/°C, and the average surface interval d002 of the (002) plane of the carbon material 2 by X-ray diffraction method after graphitization is 0.3354-0.3450 nm.SELECTED DRAWING: None 【課題】不純物の混入が少なく、安定性に優れた高品質のリチウムイオン二次電池用負極材料を得るために有用なリチウムイオン電池用電極材料用黒鉛材料。【解決手段】炭素材料に直接電流を流すことにより発熱させて黒鉛化する工程を含み、黒鉛化前の炭素材料１が密度１．４ｇ／ｃｍ3に圧縮したときの圧密粉体抵抗値が０．４Ωｃｍ以下で、安息角が２０°以上５０°以下、レーザー回折法により測定した体積基準の粒子径分布におけるＤ９０が１２０μｍ以下、３０〜１００℃の熱膨張係数ＣＴＥが４．０×１０-6／℃以上６．０×１０-6／℃以下であり、黒鉛化後の炭素材料２がＸ線回折法による（００２）面の平均面間隔ｄ００２が０．３３５４ｎｍ以上０．３４５０ｎｍ以下である黒鉛材料の製造方法。【選択図】なし