A lead-free KNN-based, co-fired multilayered piezoceramic energy harvester with a high output current and power
Qiong Wu, Faqiang Zhang, Bing Wang, Zhi Jie Cheng, Song Liu, Ronglei Zhu, Yuheng Huang, Jianglei Chang, Zhifu Liu, Shuxiang Dong
Abstract
To date, most of the reported piezoelectric energy harvesters (PEHs) use lead-based Pb(Zr,Ti)O3 (PZT) piezoceramic family, which is obviously harmful to the environment. In recent years, the PEHs constructed with lead-free piezoceramics have been developed rapidly. However, their force-to-electric (F–E) output performances are still unsatisfactory. To address this issue, here we present a PEH assembled with lead-free potassium sodium niobate (KNN) based co-fired multilayered piezoceramics (MLPCs), which show a high output current and power. First, high-quality KNN-based MLPCs are prepared by tape-casting process. Each MLPC contains 11 piezoceramic layers, and the cross-section SEM image of the MLPC indicates that the ceramic layers are well connected with the Ag/Pd inner electrode layers. The d33 of a single MLPC reaches up to 4,675 pC/N. The F–E output performance of KNN-MLPC based PEH is then tested. The inherent advantages of multilayered ceramics enable the PEH to achieve a peak-to-peak output current of up to 1.48 mA and a peak-to-peak output power of 2.19 mW under a harmonic force load of 6 kN at 14 Hz. Finally, the PEH is tested to validate its practical application in real road environments, demonstrating its promising for the use of self-powered monitoring sensors for collecting traffic data.