Lithium Intercalation Kinetics and Fast‐Charging Lithium‐Ion Batteries: Rational Design of Graphite Particles Via Spheroidization

Abstract

Graphite is the state‐of‐the‐art anode active material in lithium‐ion batteries with high specific capacity and long cycling stability. Nevertheless, due to the growing market requirements especially for the automotive sector, many efforts are dedicated to improve the fast‐charging performance of the anode. Therefore, research focuses on different levels of the anode, for example, on material level to improve the kinetics of the lithium intercalation process or by optimization at the electrode level. For anode active material production, the spheroidization of natural and synthetic graphite is a very important step that affects particle characteristics and electrochemical behavior. Herein, natural and synthetic graphite materials are spheroidized by using a lab‐scale spheroidization process. The obtained samples are characterized by means of different analytical techniques to investigate the influence of the spheroidization conditions on selected graphite characteristics that directly influence the charging rate performance. Apart from particle morphology, surface‐related properties induced by the spheroidization process show correlation with the measured lithiation rate performance.

Modeling Lithium Plating Onset on Porous Graphite Electrodes Under Fast Charging with Hierarchical Multiphase Porous Electrode Theory

“…23 Figure 6c shows respective currents through inner surfaces and outer surfaces for a particle of radius R = 4.1 μm as a function of the electrode state of charge under 1C, 3C and 4C conditions. Although relatively small particle porosity considered in this work (ϵ p = 3.4%), 71 the liquid pathway contributes about 3 times more currents than the solid way for two reasons. First, the ionic transport resistance through liquid in micropores are lower than the solid transport even at such a low particle porosity.…”