A battery design and fabrication process is demonstrated to make Lithium-ion (Li-ion) microbatteries with high capacity to power IoT devices. The battery consists of printed anode and cathode layers based on graphite and lithium cobalt oxide (LCO) respectively. The active area of the electrodes is scaled down to 1 mm2 and the resulting electrochemical performance is evaluated. These miniature batteries demonstrate a significantly higher discharge capacity (6.4 mAh/cm2) and energy density (23.6 mWh/cm2) than thin-film and thick-film, and 3D microbatteries. This work shows a miniaturized Li-ion battery capable of powering a MEMS-based wireless sensor system with peak current requirements as high as 4 mA, demonstrating its effectiveness as a power source for integrated electronics.