Metallic Ag with Suspended Network Structure Enhances the Power Generation Performance of NBT-Based Coupled Nanogenerators

Piezo-pyroelectric coupled nanogenerators (PPCNGs) capable of collecting vibration energy and thermal energy in complex environments are expected to provide a long-term power supply for multifunctional electronic devices. However, the piezoceramics as the core of the PPCNGs are limited in their coupled power generation capabilities due to low thermal conductivity and high internal resistance. In this work, it is proposed to construct Na0.5Bi0.5TiO3-K0.5Bi0.5TiO3/Ag (NBT-KBT/Ag) composite ceramics with a suspended network structure by introducing a low-melting-point metal Ag second phase. The network structure that can serve as a transmission path effectively reduces the scattering of phonons and carriers in the ceramics, improves the transport efficiency, and achieves the dual effects of increasing thermal conductivity and reducing internal resistance in the composite ceramics. And the output power density of PPCNG composed of the optimal components is 736.4 nW/cm3, which is 4.7 times that of the unoptimized virgin components. Furthermore, the optimal PPCNG possesses the capability to recognize object information through pressure and temperature sensing. This work reinforces the output characteristics of PPCNGs by constructing a suspended network structure. More importantly, the simple and efficient design strategy of constructing a suspended network structure is expected to be extended to material modification for the application of multifunctional smart electronic devices.