High Power Density Low-Lead-Piezoceramic–Polymer Composite Energy Harvester

Polymer–piezoceramic composites show mutual properties of piezoceramics and polymers that can be efficiently utilized in energy harvesting applications. Here we fabricated 0–3 composite films using high-performance low-lead piezoceramic (x)Bi(Ni
_1/2
Zr
_1/2
)O
₃
-(1-x)PbTiO
₃
(BNZ-PT) as ceramic filler and polyvinylidene fluoride (PVDF) as polymer matrix. Unlike the conventional morphotropic phase boundary piezoelectrics such as the (1-x)PbTiO
₃
-(x)PbZrO
₃
, the large piezoelectric response of the BNZ-PT can be obtained by poling-induced cubic-like-to-tetragonal phase transformation. This leads to high piezoelectric coefficient of the PVDF–BNZ-PT composite films as well as high-energy harvesting performance. Composite films with different volume fractions of ceramic showed surface power density of 1.3–
$3.5~\mu \text{W}$
/cm
²
, and volume power density of 72.2–
$175~\mu \text{W}$
/cm
³
using simple bending and unbending movements. Energy harvester in the form of cantilever fixed at both ends showed surface power density of 56.97–
$163.63~\mu \text{W}$
/cm
²
and volume power density of 3165–
$8165~\mu \text{W}$
/cm
³
in response to impact pressure pulses. The generated power from the composite films is comparable to composite energy generators reported to date. The volume power density, however, is highest to the best of our knowledge among the reported 0–3 polymer–piezoceramic composite energy harvesters.