An Electric Field‐Enhanced Ultrahigh Energy Density Micro‐Supercapacitors Printed by High Precision Maskless Photolithography

Abstract Micro‐supercapacitors (MSCs) are crucial for powering micro‐electromechanical systems (MEMS) and microelectronic devices due to their miniature size and high energy storage capacity. However, the achievement of printable high‐energy‐density MSCs with smaller size is still challenging. Herein, high‐precision (2 µm) maskless lithography is utilized on Submicron (SU‐8) photoresist successfully printing an ultrahigh energy density MSCs on silicon substrates with an effective electrode area of only 0.01 mm ² . By incorporating the design of bent electrodes, the electric field strength between electrodes is greatly enhanced and leads to the improvements of device performance. The fabricated MSCs exhibit an unprecedently high area‐specific capacitance of up to 2.13 mF cm ⁻² at a scan rate of 10 mV s ⁻¹ , and excellent cyclic stability with the MSCs retaining 91.7% of their capacitive properties after 4000 cycles. Moreover, the MSCs achieve an ultrahigh energy density of 218 µWh cm ⁻² , surpassing both traditional carbon‐based MSCs and various hybrid MSCs. This work is expected to promote the broader application of MSCs in MEMS technology and microelectronic devices.