Versatile core-shell MnO2@PANI nanocomposites: Bridging photo-assisted zinc-ion batteries and wearable strain sensors for self-powered systems

With the continuous development of self-powered sensing systems, achieving efficient energy self-supply and high-performance signal acquisition simultaneously has emerged as a main trend for next-generation sensors. However, developing functional materials for such sensing systems is still facing crucial challenges. Herein, a multifunctional MnO 2 @PANI (MP) composite material was designed to realize a synchronized “integration” strategy. Specifically, the MP serves as a cathode in photo-assisted zinc-ion batteries (PA-ZIBs), enabling solar energy conversion and storage. The p-n heterojunction formed between MnO 2 and PANI promotes effective separation of photogenerated electron-hole pairs and enhances Zn 2+ kinetics. Therefore, the PA-ZIBs deliver a high self-charging voltage of 1.08 V and 33 % enhancement in specific capacity (reaching 249.5 mAh g −1 at 0.1 A g −1 ) under illumination. Meanwhile, it also functions as the active layer of a flexible strain sensor, achieving efficient mechanical signal detection. The core–shell structure and composite component improve both structural stability and conductivity. As a result, the sensor exhibits high sensitivity, a fast response time of 0.4 s, and excellent durability over 2000 cycles. Furthermore, proof-of-concept demonstrations validate the device’s capability to simultaneously harvest solar energy and detect physiological signals. This work offers a new solution for designing self-powered sensing systems and intelligent healthcare applications by merging energy-autonomous operation with multifunctional sensing capabilities.