Synthesis of Micron-Sized LiNi_0.8Co_0.1Mn_0.1O₂ and Its Application in Bimodal Distributed High Energy Density Li-Ion Battery Cathodes

Abstract

The uniform and smaller-sized (~3 μm) LiNi0.8Co0.1Mn0.1O2 (SNCM) particles are prepared via a fast nucleation process of oxalate co-precipitation, followed by a two-step calcination procedure. It is found that the fast nucleation by vigorous agitation enables us to produce oxalate nuclei having a uniform size which then grow into micron-particles in less than a few minutes. The impacts of solution pH, precipitation time, calcination temperature, and surface modification with ZrO2 on the structural, morphological, and electrochemical properties of SNCM are systematically examined to identify the optimal synthetic conditions. A novel bimodal cathode design has been highlighted by using the combination of the SNCM particles and the conventional large (~10 μm) LiNi0.83Co0.12Mn0.05O2 (LNCM) particles to achieve the high volumetric energy density of cathode. The volumetric discharge capacity is found to be 526.6 mAh/cm3 for the bimodal cathode L80% + S20%, whereas the volumetric discharge capacity is found to be only 480.3 and 360.6 mAh/cm3 for L100% and S100% unimodal, respectively. Moreover, the optimal bi-modal cathode delivered higher specific energy (622.4 Wh/kg) and volumetric energy density (1622.6 Wh/L) than the L100% unimodal (596.1 Wh/kg and 1402.1 Wh/L) cathode after the 100th cycle. This study points to the promising utility of the SNCM material in Li-ion battery applications.

Keywords

• oxalate co-precipitation
• smaller-sized NCM
• ZrO₂-modification
• bimodal particle size distribution
• volumetric energy density