Tailored Ceramic–Metal Piezocomposite Energy Harvester with High Current Output by Controlling the Electrical Impedance

Abstract

The electrical energy obtained by the piezoelectric energy harvesters (PEHs) exhibits high voltage and low current (i.e., high impedance); thus, the electrical impedance needs to be converted to a sufficiently low level. In this work, an intuitive yet logical approach that can decrease the electrical impedance has been proposed by introducing Ag particles with high conductivity into Ba0.85Ca0.15Ti0.90Zr0.10O3 (BCTZ) ceramics to form ceramic–metal piezocomposites. The results show that the formed intragranular structure allows the piezocomposites to withstand a high poling electric field; meanwhile, the addition of Ag particles significantly reduces the electrical impedance. Thus, the BCTZ/0.04Ag piezocomposite simultaneously exhibits a high piezoelectric charge constant (d 33) and low electrical impedance. Furthermore, the BCTZ/0.04Ag PEH achieves a much larger current and power output at a smaller matching impedance compared to the BCTZ counterpart. This work provides an insight into solving the low-current problem of PEHs.

Chemical-Composition Tuning-Enabled Optimization of Structure, Properties, and Performance of Lead-Free (1 – x)BaZr0.05Ti0.95O3–(x)Ba0.92Ca0.08TiO3 Electroceramics

“…The microstructural analyses using SEM specify that the maximum grain growth is observed for the x = 0.75 sample. The average grain size increases with an increase in the concentration of the BCT8 91 135 BNT-0.3 92 92 BZT-Portland cement 93 10 CT 94 130 BZT-BCT 95 600 BT-based systems 96 150…”

Intragranular nanocomposite powders as building blocks for ceramic nanocomposites

“…For example, nanometric inclusions can enhance ferroelectric performance via domain size refinement, 27,28 while the incorporation of metallic inclusions in an electrically insulating matrix can increase dielectric permittivity by orders of magnitude via interfacial polarization effects 29,30 . Piezoelectric nanocomposites have also been designed to more effectively couple electrical–mechanical responses by preferentially locating metallic nanoinclusions within piezo‐active grains 31 …”

“…29,30 Piezoelectric nanocomposites have also been designed to more effectively couple electrical-mechanical responses by preferentially locating metallic nanoinclusions within piezo-active grains. 31 Researchers studying ceramic "nanocomposites" have developed methods to control microstructures for material systems of interest, including Al 2 O 3 -SiC, 2,32 Si 3 N 4 -SiC, 1,33 and various metal-metal oxide composites. 3,20,[34][35][36][37][38][39][40][41][42] These methods generally fall into one of the two categories: particle occlusion via grain growth, or displacement reactioninduced phase transformations.…”

Optimizing Output Power Density in Lead-Free Energy-Harvesting Piezoceramics with an Entropy-Increasing Polymorphic Phase Transition Structure

“…Piezoelectric energy harvesters (PEHs) represent a feasible solution to drive these wireless sensors, which can convert the mechanical energy that can be found everywhere in daily life into electrical energy, regarding as one of the most promising potential power technologies for the 5G era. − To date, the most commonly used materials for PEHs are still largely Pb-based materials, , which can cause serious damage to the environment and to public health. In recent years, there have been reports of lead-free PEHs, , but the low output power density of these devices still presents a bottleneck that restricts their practical application …”

“…In recent years, there have been reports of lead-free PEHs, 13,14 but the low output power density of these devices still presents a bottleneck that restricts their practical application. 15 The figure of merit (FOM), which is related directly to the output power density of the PEHs, can be given by…”