Lithium-ion batteries are some of the most efficient energy storage devices, but still, they have a margin to improve regarding matters of safety and energy density due to the limitations of conventional tape-casting processing routes. In previous papers, we have proposed the powder extrusion molding as an effective method to produce Li4Ti5O12 thick additive-free electrodes for Li-ion batteries with areal and volumetric capacities[1] as high as 15.2 mAh cm−2 and 319 mA h cm−3 at C/24 respectively. In this work a mixture of the anodic material Li4Ti5O12 and 2% w. black carbon Super C65 has been processed through powder injection molding (PIM) resulting in ceramic binder-free electrodes with ultra-thick thickness (>500 µm) electrodes. Firstly, a study of the ceramic powder mixed with a binder composed of polypropylene, paraffin wax, and stearic acid was done to find a suitable feedstock for the powder injection moulding process. As a result, disk-type green parts with 50 vol.% of ceramic powder composition were obtained. After removing the binder with solvents and subsequent thermal treatment, the parts were sintered at 900 °C aiming for a relatively high porosity, ( 25.7%). Finally, these electrodes were characterized in a half-cell against a lithium metal counter-electrode, where at relatively low rates (C/24 and C/12) they developed very high areal and volumetric capacities up to 26.0 mA·h·cm-2 and 403 mA·h·cm-3, respectively. This result justifies the capability and interest of this technology for manufacturing thick electrodes with high electrochemical performances.

[1] M.E. Sotomayor, C. de la Torre-Gamarra, W. Bucheli, J.M. Amarilla, A. Varez, B. Levenfeld, J.-Y. Sanchez
Additive-free Li4Ti5O12 thick electrodes for Li-ion batteries with high electrochemical performance
J. Mater. Chem. A., 6 (2018), pp. 5952-5961