The paper presents a novel 3D printing technique for fabricating interdigitated Li-ion microbatteries with high-aspect ratio anode and cathode micro-arrays. These microbatteries, composed of Li₃Ti₅O₁₂ (LTO) and LiFePO₄ (LFP), exhibit high areal energy and power densities. The 3D printing process involves the precise deposition of concentrated inks through fine nozzles, followed by sintering to enhance structural integrity. The inks are optimized for rheological properties to ensure reliable flow and adhesion during printing. The fabricated microbatteries demonstrate good electrochemical performance, with specific capacities of 160 and 131 mAh g⁻¹ for LFP and LTO electrodes, respectively, at a C rate of 1 C. The packaged 3D-IMA microbatteries show a stable working voltage of 1.8 V and a capacity of 1.2 mAh cm⁻², though they lack long-term cyclability due to the lack of hermetic packaging. The Ragone plot compares the areal energy and power densities of the 3D-IMA with other microbatteries, showing competitive performance. This technology has potential applications in autonomously powered microelectronics and biomedical devices.The paper presents a novel 3D printing technique for fabricating interdigitated Li-ion microbatteries with high-aspect ratio anode and cathode micro-arrays. These microbatteries, composed of Li₃Ti₅O₁₂ (LTO) and LiFePO₄ (LFP), exhibit high areal energy and power densities. The 3D printing process involves the precise deposition of concentrated inks through fine nozzles, followed by sintering to enhance structural integrity. The inks are optimized for rheological properties to ensure reliable flow and adhesion during printing. The fabricated microbatteries demonstrate good electrochemical performance, with specific capacities of 160 and 131 mAh g⁻¹ for LFP and LTO electrodes, respectively, at a C rate of 1 C. The packaged 3D-IMA microbatteries show a stable working voltage of 1.8 V and a capacity of 1.2 mAh cm⁻², though they lack long-term cyclability due to the lack of hermetic packaging. The Ragone plot compares the areal energy and power densities of the 3D-IMA with other microbatteries, showing competitive performance. This technology has potential applications in autonomously powered microelectronics and biomedical devices.