VO<sub>2</sub>-Polymorph-Dependent Energy-Storage Performance of Laser-Scribed Flexible Microsupercapacitors
Ashok Kumar S, Savitridevi Nadavurmath, Surjit Sahoo, Gurunatha Kargal Laxminarayana, Chandra Sekhar Rout
Abstract
With the rapid advancement of portable electronic devices, the demand for miniaturized and integrated energy-storage systems has grown significantly. Among these, microbatteries and microsupercapacitors (MSCs) play a crucial role in powering next-generation wearable and flexible electronics. In this study, we report high-performance MSCs based on various polymorphs of vanadium dioxide (VO 2 ), including VO 2 (A), VO 2 (B), VO 2 (D), and VO 2 (M) on laser-induced graphene (LIG) polyimide (PI) films. Through comprehensive electrochemical characterization, we found that the flexible VO 2 (M)-based MSC exhibited a superior energy-storage performance, delivering a high specific energy of 0.66 mWh cm –2 and a power density of 858 W cm –2, outperforming other VO 2 polymorphs. Furthermore, the device demonstrated remarkable mechanical flexibility, maintaining a stable electrochemical performance even at bending angles of 0°, 120°, and 180°. These findings highlight the potential of VO 2 (M)-based MSCs as promising candidates for all-solid-state, flexible, miniaturized energy-storage devices, paving the way for their integration into next-generation portable and wearable electronic devices.