N-Doped Carbon-Stabilized CoSe/NiSe2 Heterojunction Toward High-Performance Supercapacitors and Photorechargeable Power Systems

Photorechargeable power systems (PPSs) based on supercapacitors (SCs) provide a sustainable solution for alleviating the energy crisis. However, sluggish kinetics in SCs are insufficient to meet the requirements of rapid photogenerated charge storage; achieving efficient self-charging remains a challenge. Here, PPSs integrating flexible solid-state asymmetric SCs (FSASs) with N-doped carbon-stabilized CoSe/NiSe 2 heterojunction (N-C@CoSe/NiSe 2 ) and flexible solar cells (FSs) are precisely designed to achieve efficient self-charging capacity. Theoretical calculations reveal that the robust built-in electric field (BIEF) at the heterointerface accelerates electron reconstruction and enhances the affinity of OH − , thereby endowing abundant electroactive sites and fast reaction kinetics. The stable interfacial chemical bond between the N-C frame and the CoSe/NiSe 2 heterojunction significantly strengthens the BIEF while buffering volume expansion during electrochemical, improving the integral structural stability. The N-C@CoSe/NiSe 2 ingeniously combines synergistic optimization of reaction kinetics and structural stability, achieving high capacitance (2124 F g −1 ) and excellent cycling stability. The assembled FSASs deliver excellent energy storage capacity (70.8 Wh Kg −1 ). More importantly, integrated PPSs achieve a highly efficient photogenerated charge storage capacity of 4.5 V min −1 and sustainability, powering wearable electronic devices and small unmanned aircraft. This work provides scientific insights and guidance for designing robust heterogeneous and advancing the exploitation of next-generation sustainable power systems.