High-capacity Li4Ti5O12-C thick ceramic electrodes manufactured by powder injection moulding

Abstract

Lithium-ion batteries are the most efficient electrochemical energy storage devices. However, there is still room for improvement in terms of safety and energy density, presently limited by conventional tape-casting electrode processing. In this study, a blend of the anodic material Li4Ti5O12 with 2 wt% carbon black has been processed through powder injection moulding (PIM) yielding, after subsequent debinding and sintering processes, to ultra-thick (>500 µm) ceramic binder-free electrodes. The mixture of Li4Ti5O12 with the thermoplastic binder composed of polypropylene, paraffin wax, and stearic acid is investigated to identify a rheologically suitable feedstock for the PIM process. The resulting disk-type green parts contain 50 vol% of ceramic powder. After removing the binder with solvents and subsequent thermal treatment, the parts are sintered at 900 °C, aiming for a relatively high porosity, i.e., 25.7%. The resulting electrodes show very high areal and volumetric capacities up to 26.0 mA·h·cm−2 and 403 mA·h·cm−3 at C/24, respectively, in a half-cell against lithium metal.