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Due to the self-supplied energy requirements of wearable electronic devices, flexible piezoelectric energy harvesters (FPEHs) that can convert the vibration energy in the environment into electrical energy have received widespread attention in recent years. The key to increasing the power generation capacity of FPEHs is to increase the piezoelectric charge constant d33 while reducing the internal resistance, which is still a huge challenge for ceramic/polymer composites. In this work, a synergistic effect is used to construct FPEHs with high power generating capacity. On the one hand, a highly electroactive 0.2Pb(Zn1/3Nb2/3)O3–0.8Pb(Zr1/2Ti1/2)O3 (PZN–PZT) ceramic skeleton is constructed through a freeze-casting method to greatly increase the d33 of a PDMS based composite. On the other hand, multi-walled carbon nanotubes (MW-CNTs) are introduced as a bridging phase to reduce the internal resistance of the composite. The 2–2 type PZN–PZT/MW-CNTs/PDMS piezocomposite prepared using this strategy has a d33 as high as 144 pC N−1, which is significantly better than those of previously reported composites. The FPEH with dimensions of 1.5 × 1.5 × 0.1 cm3 can light 22 LEDs through the rectifier circuit without any storage units, showing an important application prospect for self-supply of energy in wearable electronic devices.

Based on the strong demand for self-powered wearable electronic devices, flexible piezoelectric energy harvesters (FPEHs) have recently attracted much attention. A polymer-based piezocomposite is the core of an FPEH and its transduction coefficient (d33 × g33) is directly related to the material's power generation capacity. Unfortunately, the traditional 0–3 type design method generally causes a 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, a unique interconnected skeleton design strategy has been proposed to overcome these shortcomings. By using the freeze-casting method, an 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 the filler and PDMS as the polymer matrix. Both the theoretical simulation and the experimental results revealed a remarkable enhancement in the stress transfer ability and piezoelectric response. In particular, the 2–2 type piezocomposite has an ultrahigh transduction coefficient of 58 213 × 10−15 m2 N−1, which is significantly better than those of previously reported composite materials, and even textured piezoceramics. This work provides a promising paradigm for the development of high-performance FPEH materials.