An ultrathick electrode (≈0.4 mm) with ultrafine Ni nanoparticles (≈5 nm) anchored on a 3D reduced graphene oxide framework is designed as cathode for Li‐CO2 batteries via 3D printing technique and thermal shock treatment (1900 K for 54 ms). The electrode exhibits low overpotential, long cycling life, good rate capability, and high areal capacity for Li‐CO2 batteries. Abstract Li‐CO2 batteries have emerged as a promising energy storage technology due to their high theoretical energy density. A thick electrode design is an effective approach for further increasing the energy density on device level by decreasing the weight and volume ratios of inactive materials. Exploring and designing novel thick electrodes with high catalytic activity toward reversible reaction between lithium and carbon dioxide are key challenges to achieve a low charge overpotential, long cycling stability, and high rate performance. Herein, an ultrathick electrode (≈0.4 mm) design for Li‐CO2 batteries by anchoring ultrafine Ni nanoparticles (≈5 nm) on a 3D‐printed reduced graphene oxide framework via thermal shock (1900 K for 54 ms) is demonstrated. The cathode displays low overpotential of 1.05 V at 100 mA g−1, high cycling stability of over 100 cycles, and good rate capability (up to 1000 mA g−1). In particular, a high areal capacity of 14.6 mA h cm−2 can be achieved due to the thick electrode design and uniform distribution of ultrafine catalyst nanoparticles. The strategy of combining an advanced 3D printing technique with fast thermal shock represents a promising direction toward thick electrode design in energy storage devices that are not limited to Li‐CO2 batteries.
Published in: "Advanced Functional Materials".