Interfacial kinetics and low-temperature behavior of spheroidized natural graphite particles as anode for Li-ion batteries.

Fast-charge and low-temperature performance is a key requirement for Li-ion battery applications such as automotive. The kinetics of Li⁺ intercalation into graphite anode is one of the main limiting factors for charging the cell at relatively low temperatures or high current densities. Spherical graphite particles are generally obtained by mechanical milling process and have several advantages for anode fabrication. In this study, we show that the milling conditions applied for spheroidization of natural graphite have a significant influence on the Li⁺ intercalation rate, and affect the kinetics of the charge-transfer reaction as revealed by electrochemical impedance spectroscopy analysis. The surface physical and chemical properties of the graphite particles after mechanical shaping mostly determine the rate of the lithiation reaction. Graphite particles with large amount of prismatic and defect-rich surfaces are associated with faster Li⁺ intercalation, and thus suitable for designing natural graphite particle as active material with promising capacity at low-temperature and high-charging rates. [ABSTRACT FROM AUTHOR]