Probing the Effect of High Energy Ball Milling on the Structure and Properties of LiNi1/3Mn1/3Co1/3O2 Cathodes for Li-Ion Batteries

Abstract

Particle size plays an important role in the electrochemical performance of cathodes for lithium-ion (Li-ion) batteries. High energy planetary ball milling of LiNi1/3Mn1/3Co1/3O2 (NMC) cathode materials was investigated as a route to reduce the particle size and improve the electrochemical performance. The effect of ball milling times, milling speeds, and composition on the structure and properties of NMC cathodes was determined. X-ray diffraction analysis showed that ball milling decreased primary particle (crystallite) size by up to 29%, and the crystallite size was correlated with the milling time and milling speed. Using relatively mild milling conditions that provided an intermediate crystallite size, cathodes with higher capacities, improved rate capabilities, and improved capacity retention were obtained within 14 μm-thick electrode configurations. High milling speeds and long milling times not only resulted in smaller crystallite sizes but also lowered electrochemical performance. Beyond reduction in crystallite size, ball milling was found to increase the interfacial charge transfer resistance, lower the electrical conductivity, and produce aggregates that influenced performance. Computations support that electrolyte diffusivity within the cathode and film thickness play a significant role in the electrode performance. This study shows that cathodes with improved performance are obtained through use of mild ball milling conditions and appropriately designed electrodes that optimize the multiple transport phenomena involved in electrochemical charge storage materials.

Controlling interlayer interactions in vanadium pentoxide-poly(ethylene oxide) nanocomposites for enhanced magnesium-ion charge transport and storage

“…Electrodes were fabricated from a slurry composed of 80 wt% active material (typically ~150-200 mg of sample), 10 wt% conductive carbon (TIMCAL Super C65), and 10 wt% binder (Arkema, Kynar HSV900 -5% in N-Methyl-2-pyrrolidinone (NMP)) using a similar method previously reported[47]. Excess NMP was added to control the viscosity of the slurry.…”

Advances and Prospects of Surface Modification on Nickel‐Rich Materials for Lithium‐Ion Batteries†

“…Since a variety of materials are blended by high‐energy ball milling, improper milling times and/or speeds will more or less break the structural integrity of spherical secondary particles. [ 111 ] Besides, the types of coating materials used in dry coating process are generally composed of nanoparticles, which tend to aggregate on the surface of cathode materials, protecting some areas but leaving other areas exposed (Figure 3). To maximize the protective areas, more nanoparticles need to be deposited to form a complete but thick coating layer, which can be as thick as 100 nm.…”

The Influence of Structure on the Electrochemical and Thermal Response of Li-Ion Battery Electrodes

“…Taleghani et al also performed studies on the effect of particle size distributions on cell performance. Stein et al performed various studies on how particle size affects the cell performance [12] and showed that the planetary ball milling of electrode materials resulted in smaller crystallite size. However, the benefits of the size reduction were found to be limited in some cases, with intermediate crystallite sizes showing better overall performance due to reduced agglomeration and lower interfacial resistance.…”

“…It has been shown that the performance of thick electrodes can be enhanced by increasing the porosity and decreasing the tortuosity of the electrodes [16]. Other parameters related to electrode structure and particle size can influence battery performance [12,13].…”