Utilizing FeS2 Deposition on 3D Printed Carbon Microlattices as Free-Standing Electrodes in Lithium-Ion Batteries

Abstract

Free-standing electrodes are a great alternative to slurry-coated battery electrodes as they eliminate the need for inactive components and shorten the fabrication process. In this work, carbon microlattice templates are designed and fabricated through the use of 3D stereolithography followed by pyrolysis to create a well-defined carbon template with a resolution >35 µm. Iron disulfide, a material with a high specific theoretical capacity, is then deposited on the surface and used as electrode material in lithium-ion batteries. To date, there have been no reports of FeS2 combined with 3D printed free-standing electrodes. The design utilizes controlled microchannels along the thickness direction to facilitate efficient ion transfer and interconnected carbon skeletons for electron transfer throughout the entire electrode. When directly applied in a lithium-ion battery, the composite material displayed a specific capacity of 562.5 mAh g-1 after 200 cycles with a current density of 500 mA g-1. A high-rate capability was also achieved. Stepwise cyclic voltammetry and Dunn Method confirm that the dominant mechanism guiding the excellent electrochemical performance is diffusion-controlled process, further highlighting the benefits of the organized microchannels. These results will advance the development of composite electrodes as well as shine light on the immense potential to develop high energy density batteries utilizing 3D printing, advocating for sustainable energy from both a research-driven and practical stance.