A Microwire Embedded with a NiSe2/MoSe2 Microsupercapacitor with Photoinduced Ultrahigh-Energy Amplification

Microsupercapacitors (MSCs) have emerged as promising miniaturized energy-storage devices for self-powered electronics. However, their practical adoption is hindered by insufficient energy density, poor stability, and short lifespan, necessitating solutions for improved practicability. Herein, we report a novel microwire embedded NiSe₂/MoSe₂ (NMS) heterostructure MSC that addresses these challenges through photoenhanced energy storage. The device showcases a remarkable performance with a volumetric capacitance of ∼1014 F cm^–3, an energy density of ∼140 mWh cm^–3, and a power density of ∼1.6 W cm^–3. Density functional theory calculations reveal 33-fold higher quantum capacitance and 16-fold lower OH^– ion adsorption energy compared to pristine monometallic counterparts. Notably, the device powers a red light-emitting diode for 3 min after 1 min of charging, supports a healthcare monitoring device for up to 6 h, and retains ∼100% capacitance over 60000 cycles with 95% Columbic efficiency. Overall, this strategy offers a viable pathway to improve the MSC performance for next-generation microelectronics and biomedical applications.