Multi-energy conversion of Gd5 (Si2Ge2)-poly (vinylidene fluoride), a hybrid material

A class of multiphase composites is reported here. These composites consist of magnetocaloric Gd5Si2Ge2 (GSG) particles embedded in a polyvinylidene fluoride (PVDF) matrix. Under an external magnetic field, those materials were found to generate an electrical voltage up to 0.11 V, equivalent to the power density of 14.3 mW/cm3 Oe when the concentration of Gd5Si2Ge2 was at 4 wt. %. This was due to the magnet-induced strain in Gd5Si2Ge2 leading to the voltage generation in the piezoelectric polymer. The power density of the hybrid system has proven to be significantly higher than each single phase alone. When tested individually PVDF has a power density of 3.25 mW/cm3 Oe and Gd5Si2Ge2 has 0 power output. The coupling of magnetic and piezoelectric effects enables multi-energy conversion that is unique for device design and clean energy harvesting.