Ultrastrong-polar cyano-Prussian blue analogs hybrid tribomaterials for biomechanical energy harvesting and self-powered sensing

Triboelectric nanogenerators (TENGs) are green energy devices that can convert mechanical energy into electrical energy. However, lower output power density currently hinders its realistic applications. Introducing functional materials into dielectric polymers layer is an efficient approach to enhance TENG output. Herein, a low-cost, biocompatible Prussian blue analog (K_xMn[FeCN)₆]_y·zH₂O, MnFePBA) is proposed as a functional component for high-performance hybrid tribomaterials of TENGs. Numerous highly polar C[tbnd]N groups found in MnFePBA can interact dipole-dipole with the C-F bond in PVDF, promoting the formation of electroactive β-phase PVDF and enhancing the capacity for charge induction and charge capture. Simultaneously, the weak interface fusion between the inorganic material and the organic polymer can be improved as the O-H bond in MnFePBA can establish a stronger hydrogen bond with the C-F bond in PVDF. Additionally, high dielectric MnFePBA can enhance the dielectric properties of PVDF/MnFePBA to boost the TENG output. Consequently, the PVDF/MnFePBA can achieve evidently increased short-circuit current of 31.2 µA, output voltage of 1580 V and ultra-high power density of 12.8 W/m² (4 ×4 cm²). Moreover, the assembled TENG could also be efficiently utilized for human motion capture and sensing applications. This work enriches the range of functional components for high-performance tribomaterials of TENGs.