Simultaneously improved dipolar interaction at inorganic-inorganic and organic-inorganic interfaces for multimode energy harvesting from heterostructured CoFe2O4@BCZT loaded P(VDF-TrFE)

Hybrid CoFe₂O₄@0.5(Ba_0.7Ca_0.3)TiO₃-0.5Ba(Ti_0.8Zr_0.2)O₃ (CF@BCZT) heterostructured nanomaterials have been incorporated into poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) to achieve enhanced magnetoelectric (ME) performance in flexible polymeric composites. The magnetostriction of CF, in this case, stimulates both the P(VDF-TrFE) and highly piezoelectric BCZT dipoles at inorganic-organic and inorganic-inorganic interfaces, respectively, thereby achieving ME coupling coefficient as high as 96 mV·cm^-1·Oe^-1. The optimized device shows excellent DC and AC magnetic field sensitivity and associated magnetic field energy harvesting ability. On the other hand, due to high polarity of the developed composites and high tribo-negativity of PVDF, the developed films show excellent performance as piezoelectric and piezo-tribo hybrid nanogenerators (PENGs and HNGs, respectively) too. The optimized PENG delivers ~ 75 µW/cm² of power density with ~ 46% of efficiency and is able for efficient static and dynamic pressure sensing, bending strain sensing, and associated piezoelectric energy harvesting. On the other hand, the optimized HNG, with ~ 255 µW/cm² of output power density, shows its excellent performance for various regular and irregular biomechanical and ambient mechanical energy harvesting, associated self-powered sensing, and powering up small electronics. Thus, the developed composites can be regarded as an excellent multifunctional material for highly efficient multi-mode (magnetoelectric, piezoelectric, and piezo-tribo hybrid) energy harvesting and sensing.