High-areal capacity and binder-free thick-ceramic LFP electrodes manufactured by robocasting for Li-ion batteries

To address the growing demands for energy density, power, lifetime, and safety in Li-ion batteries, innovative processing techniques for high-capacity electrodes are essential. This study explores the additive manufacturing of ultra-thick LiFePO 4 (LFP) electrodes (∼800 μm) using robocasting, as an alternative to traditional methods like screen printing or pressing. 3D LFP-based electrodes with cellular architectures and high mass loading (∼20 mg) are designed to enhance ion transport and energy density by increasing the surface area. Eco-friendly, aqueous-based printable inks are optimized for suitable rheological properties (viscosity, modulus, yield strength), in agreement with scalable and sustainable production. To improve mechanical strength and conductivity, 3 wt% of graphene oxide (GO) or graphene nanoplatelets (GNP) are incorporated to the ink formulation. After printing, 3D structures undergo thermal debinding and sintering to remove inactive components, yielding additive-free electrodes. Microstructural, mechanical, and electrical characterizations reveal that GO incorporation increases Vickers hardness by 50 % without compromising compressive strength. Electrochemical testing with Li 4 Ti 5 O 12 (LTO) as the anode demonstrates promising performance, with LFP-GO electrodes achieving areal capacities up to 11 mA h cm −2 (21 mW h cm −2 ) at C/25. These results highlight the potential of robocasting to produce robust, high-performance thick electrodes for next-generation Li-ion batteries. • Ultra-thick LiFePO 4 electrodes (∼800 μm,∼20 mg cm −2 ) successfully fabricated by robocasting. • Graphene oxide (GO) fillers improved both electrical conductivity ( × 10) and hardness (+50 %). • LFP-GO electrodes achieved high areal capacities (11 mA h cm −2 at C/25).