High-performance black phosphorus (BP)-based micro-supercapacitors (MSCs) hold immense promise for wearable electronics but remain hampered by the material’s intrinsic instability and sluggish electron kinetics. Herein, a two-dimensional phosphorene and bismuthene (2D BP/Bi) heterojunction via liquid nitrogen-assisted exfoliation and mask-assisted filtration was developed as a robust bifunctional electrode for integrated flexible energy-sensing systems. The heterostructure effectively suppresses nanosheet restacking and enhances interfacial stability through strong P-O-Bi covalent bonding and interfacial synergy. Simultaneously, the incorporation of bismuthene constructs high-speed electron transport channels, significantly facilitating ion diffusion and charge transfer. Consequently, the optimized electrode achieved a high areal capacitance of 7.6 mF cm^-2 (1.6-fold enhancement over pure BP) and an ultra-long lifespan with 92.1% retention after 30,000 cycles. Notably, by tailoring the gel electrolyte with DMSO, the device exhibited remarkable freeze-tolerance, maintaining 70% capacitance at -35 °C. Furthermore, an all-flexible integrated system combining the MSC with a pressure sensor was constructed using graphene current collectors, enabling continuous, self-sustained physiological monitoring. This work offers critical insights into interface engineering for designing high-performance BP-based MSCs and paves the way for extreme-environment wearable applications.

The escalating demand for micro/nano-sized devices, such as micro/nano-robots, intelligent portable/wearable microsystems, and implantable medical microdevices, necessitates the expeditious development of integrated microsystems incorporating energy conversion, storage, and consumption. Critical bottlenecks in microscale energy storage/sensors and their integrated systems are being addressed by exploring new technologies and new materials, e.g., MXene, holding great potential for developing lightweight and deformable integrated microdevices. This review summarizes the latest progress and milestones in the realization of MXene-based micro-supercapacitors (MSCs) and sensor arrays, and thus discusses the design fundamentals and key advancements of MXene-based energy conversion-storage-consumption integrated microsystems. Finally, we outline the key challenges in fabricating MXene-based MSCs/sensors and their self-powered integrated microsystems, which is crucial for their practical applications. Particularly, we illuminate viable solutions to such unsolved issues and highlight the exciting opportunities.