Effect of particle size and hierarchical structuring on the electrochemical properties of NCM-cathode materials in lithium-ion-batteriesThursday (27.09.2018) 09:15 - 09:30 S1/03 - 221 Part of:
In the course of energy crisis energy revolution is taking place with important changes to renewable energy sources. In this process lithium ion batteries (LIBs) are one key technology concerning energy storage and electromobility because of their high efficiency and their environmental-acceptability. Nevertheless, shortcomings are still their unsatisfying energy density, which goes along with the driving range of automobiles, their poor rate capability especially at high cycling rates and lack of long-term cyclability. One simple approach to concern named problems and increase the reliability of LIBs, is to modify the cathode design in order to adapt it to their applications. Pioneering are hierarchically structured composites since they unite the positive effects of nano-structuring with shorter diffusion paths, improved conductivities, suppression of structural changes with the manageability of powder particles in micron range.
In the following the approach of hierarchically structuring of LiNi1/3Co1/3Mn1/3O2 (NCM111) cathode active material by an elaborated process of grinding, spray drying and calcination will be presented. Here the effects of granule size and primary particle size variation by spray drying and calcination will be presented. The relationship between process parameters, morphology and performance of the as prepared LIBs will be given by detailed material characterization in combination with electrochemical investigations. It will be shown that active material granules between 9 and 42 µm with nanostructured morphology and defined porosity have superior discharge capacities, power densities and long-term stabilities compared to bulk NCM-material. An accurate tuning of the performance at high C-rates can be reached by granule size optimization and adaption of calcination temperature.