New Synthesis Method for Cathode Materials for High Energy Lithium Ion Batteries
Nickel-rich layered oxides such as lithium nickel cobalt aluminium oxides (NCA) are promising cathode materials for high-energy lithium ion batteries. The addition of aluminium improves the thermal and structural stability of the cathode materials.
A major challenge in the synthesis of these materials is however the homogeneous inclusion of aluminium during typical co-precipitation reactions.
In a joint research project, scientists from MEET Battery Research Center of the University of Münster and SUNUM of Sabanci University in Istanbul developed an alternative synthesis process for NCA cathode materials that precisely fulfils this need.
Stable Nickel-Rich Cathode Materials
The newly developed process is based on a sacrificial carbon fiber (CF) template-assisted synthesis by a modified Pechini method. This synthesis procedure for highly homogeneous oxide materials makes it possible to homogenously integrate aluminium into the NCA precursor structure while simultaneously adapting the particle morphology.
"By synthesizing the particles with the CF template, we generate anisotropic surfaces whose physical, mechanical and chemical properties are directionally dependent. These not only facilitate Li+ ion transport within the cell, but also stabilise cathode materials for high voltage and high temperature operation," explains MEET scientist Dr Aurora Gomez Martin.
Since the synthesis method allows a straightforward route for tailoring particle size, shape and crystallinity, stable nickel-rich cathode materials can be developed. Dr Buse Bulut Köpüklü from SUNUM in Istanbul, who completed an eight-month internship at MEET Battery Research Center, concludes: "The materials synthesized with our method show superior performance compared to common cathode materials synthetized in the absence of the carbon fibre template. Our study can therefore pave the way for further tailoring and optimization of the synthesis of NCA cathode materials."
Source: University of Münster