Neutron-scattering studies on carbon anode materials used in lithium-ion batteries

High-resolution neutron powder diffraction (NPD) and small-angle neutron scattering (SANS) experiments were carried out on several different types of carbon used as anodes in secondary lithium-ion batteries. The materials selected were Swedish natural graphite (crude and jet-milled), meso-carbon microbeads, and hard carbon. SANS data revealed a nanopore structure in hard carbon. Absolute calibration of SANS data for hard carbon was done to calculate the volume fraction of the nanopores. Estimation of the hexagonal (A B) and the rhombohedral (ABC) phase content in Swedish natural graphite from NPD data revealed that the jet milling increased the amount of the ABC phase. All these results are discussed to explain the electrochemical performances and structure-property relations of different carbon anode materials.