Interface-stabilized phosphorene/bismuthene heterostructures for freeze-tolerant micro-supercapacitors and integrated sensing

• • The optimized BP/Bi (3:1) heterojunction electrode delivers an areal capacitance of 7.6 mF·cm−2, a 1.6-fold enhancement over pure BP, directly addressing the low energy density bottleneck in BP-based micro-supercapacitors. • • The device retains 92.1% of its initial capacitance after 30,000 charge/discharge cycles, demonstrating exceptional long-term operational stability critical for reliable wearable electronics. • • With DMSO-modified gel electrolyte, the MSC maintains 70% of room-temperature capacitance at −35 °C, enabling freeze-tolerant operation for extreme-environment applications. • • The integrated system exhibits ultra-fast response time of ~48 ms and negligible signal attenuation over 900 cycles, validating its suitability for real-time physiological monitoring.