GRAPHITE-BASED NEGATIVE ELECTRODE ACTIVE MATERIAL AND MANUFACTURING METHOD THEREOF

• Main Authors: TAKAGI YASUSHI, MATSUBARA SHINSUKE, KOYAMA YUTAKA, KUME TETSUYA, ONO YUSUKE
• Format: Patent
• Language: English; Japanese
• Published: 01.11.2022
• 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

To provide a graphite-based negative electrode active material capable of suitably reducing the low-temperature resistance of a secondary battery.SOLUTION: A graphite-based negative electrode active material 1 includes graphite particles 10 and an amorphous carbon layer 12 covering at least a part of the graphite particles. Here, in the cross-sectional TEM image of the graphite-based negative electrode active material 1, when a distance from the surface of the graphite-based negative electrode active material in the amorphous carbon layer 12 to the graphite particles 10 is divided into three equal layers, an A layer, a B layer, and a C layer from the surface, the progress of crystallization in the A layer, the B layer, and the C layer increases in this order.SELECTED DRAWING: Figure 1 【課題】二次電池の低温抵抗を好適に低減することができる黒鉛系負極活物質材料を提供すること。【解決手段】ここで開示される黒鉛系負極活物質材料１は、黒鉛質粒子１０と、該黒鉛質粒子の少なくとも一部を被覆する非晶質炭素層１２とを備えている。ここで、黒鉛系負極活物質材料１の断面ＴＥＭ画像において、非晶質炭素層１２における該黒鉛系負極活物質の表面から黒鉛質粒子１０に至るまでの間を、該表面に近い方からＡ層、Ｂ層、Ｃ層に３等分したとき、該Ａ層、Ｂ層、Ｃ層における結晶化の進行具合はこの順に大きくなる。【選択図】図１