Flexible Piezoelectric Energy Harvester with Ultrahigh Transduction Coefficient by Interconnected Skeleton Design Strategy
Based on the strong demand for self-powered wearable electronic devices, flexible piezoelectric energy harvester (FPEH) has recently attracted much attention. Polymer-based piezocomposite is the core of FPEH and its transduction coefficient (d33×g33) is directly related to the material's power generation capacity. Unfortunately, traditional 0-3 type design method generally causes the weak stress transfer and poor dispersion of the filler in the polymer matrix, making it difficult to obtain a high d33·g33. In this work, an unique interconnected skeleton design strategy has been proposed to overcome these shortcomings. By using freeze-casting method, the ice-templated 2-2 type composite material has been constructed with the popular piezoelectric relaxor 0.2Pb(Zn1/3Nb2/3)O3–0.8Pb(Zr1/2Ti1/2)O3 (PZN–PZT) as filler and PDMS as polymer matrix. Both the theoretical simulation and the experimental results revealed the remarkable enhancement in the tress transfer ability and piezoelectric response. In particular, the 2-2 type piezocomposite has a ultrahigh transduction coefficient of 58,213×10-15 m2/N, which is significantly better than previously reported composite materials, and even textured piezoceramics. This work provides a promising paradigm for the development of high-performance FPEH materials.