This study presents a novel 3D printing technique for fabricating interdigitated Li-ion microbattery architectures with high areal energy and power densities. The method involves printing high-aspect ratio anode and cathode micro-arrays on a sub-millimeter scale using concentrated inks of Li4Ti5O12 (LTO) and LiFePO4 (LFP). These materials exhibit minimal volumetric expansion, reducing the need for electrode compliance during charge and discharge cycles. The 3D printing process enables precise patterning of functional inks over areas ranging from 100s μm² to 1 m² with minimum feature sizes as small as 1 μm. The inks are optimized for reliable flow through fine nozzles, promoting adhesion and structural integrity. After printing, the electrodes are annealed at 600°C to remove organic additives and promote nanoparticle sintering. The resulting microbatteries exhibit high areal energy densities of 9.7 J cm⁻² and power densities of 2.7 mW cm⁻². The study also demonstrates the electrochemical performance of the microbatteries, showing good cycle life and rate capability. The packaged microbatteries, however, face challenges in long-term cyclability due to lack of hermeticity. The results indicate that the high-aspect ratio structures enable efficient ion and electron transport, contributing to the high energy and power densities. The approach can be extended to other lithium-ion chemistries to achieve competitive volumetric energy densities. The study highlights the potential of 3D printing in fabricating microbatteries for autonomous microelectronics and biomedical devices.This study presents a novel 3D printing technique for fabricating interdigitated Li-ion microbattery architectures with high areal energy and power densities. The method involves printing high-aspect ratio anode and cathode micro-arrays on a sub-millimeter scale using concentrated inks of Li4Ti5O12 (LTO) and LiFePO4 (LFP). These materials exhibit minimal volumetric expansion, reducing the need for electrode compliance during charge and discharge cycles. The 3D printing process enables precise patterning of functional inks over areas ranging from 100s μm² to 1 m² with minimum feature sizes as small as 1 μm. The inks are optimized for reliable flow through fine nozzles, promoting adhesion and structural integrity. After printing, the electrodes are annealed at 600°C to remove organic additives and promote nanoparticle sintering. The resulting microbatteries exhibit high areal energy densities of 9.7 J cm⁻² and power densities of 2.7 mW cm⁻². The study also demonstrates the electrochemical performance of the microbatteries, showing good cycle life and rate capability. The packaged microbatteries, however, face challenges in long-term cyclability due to lack of hermeticity. The results indicate that the high-aspect ratio structures enable efficient ion and electron transport, contributing to the high energy and power densities. The approach can be extended to other lithium-ion chemistries to achieve competitive volumetric energy densities. The study highlights the potential of 3D printing in fabricating microbatteries for autonomous microelectronics and biomedical devices.