Effects of Nano-Micro Hierarchical Architecture Intraparticle Connectivity and Carbon Black-LiNi1/3Mn1/3Co1/3O2 Interaction: An Energy-Power Tradeoff In Lithium-Ion Batteries

Abstract

The performance of lithium-ion batteries depends on the morphology and distribution of components in the electrode. LiNi1−x−y Mn x Co y O2 (NMC) with nano-micro hierarchical structure is a commercially important cathode material for electric vehicle application. The commonly used slurry preparation method is to dry-mix the active material with a conductive additive and then disperse it in the binder solution. The energy imparted during premixing, while helping in controlling the distribution of CB to establish conducting network, can deteriorate NMC by mechanically dismantling the aggregate structure. Herein, a comprehensive effort is put forward to understand dry-mixing by high-energy ball-milling. It is found that mixing-intensity influences the establishment of both long-range and short-range electronic conductive pathways.The sample mixed with very low intensity and high intensity exhibited a capacity of 68 mAh.g−1 and 20 mAh.g−1 respectively, while the sample with optimum mixing exhibited 100 mAh.g−1 at 5C. This study highlights the guidelines for preparing electrodes for high-energy and high-power applications. At low C-rates, the capacity depends on the integrity of the microstructure of NMC, while at high C-rate optimum short and long-range electronic conductivity is the deciding factor.