Researchers at Tsinghua University and other institutes in China have unveiled a new technique to refine relaxor ferroelectrics for energy storage.
Relaxor ferroelectrics are materials known for their ferroelectric traits and pronounced electrostriction, meaning they can change shape in response to electric fields. These materials can be harnessed to produce efficient energy storage tools like capacitors. Capacitors, essential electronic elements, consist of two-spaced electrical conductors and can briefly hold an electric charge. This capacity to store charge minimizes noise in integrated circuits, enhancing the efficiency of electronics.
Researchers at Tsinghua University and other institutes in China have introduced a novel method to optimize relaxor ferroelectrics for energy storage devices. Recent research has sought to enhance capacitor energy storage using relaxors with a singular high-entropy composition.
The team have examined the relationship between relaxor ferroelectric characteristics and entropy. They discovered that as relaxor entropy rises, local inhomogeneity increases, influencing the material’s properties. The findings show increased local inhomogeneity with entropy, as observed through scanning transmission electron microscopy. This subsequently modulates the relaxor characteristics. Through meticulous entropy design, the researchers have achieved superior energy storage performance in Bi4Ti3O12-based medium-entropy films, boasting a high energy density of 178.1 J cm−3, an efficiency surpassing 80%, and an impressive figure of merit of 913.
The researchers have found that relaxor ferroelectric materials’ characteristics hinge on entropy, especially configurational entropy, which can be determined using a material’s compositions. Their recent research opens the door to crafting relaxers to enhance capacitors and other energy storage devices. Using their method, the team produced high-performance relaxor films, leading to a capacitor prototype. The team highlights that using the medium-entropy films as dielectric layers have developed a multilayer film capacitor prototype surpassing traditional multilayer ceramic capacitors.
In the future, the work by the researchers could guide the creation of novel ferroelectric relaxors with enhanced characteristics. Such materials could pave the way for superior capacitors, ushering in a new era of advanced electronic devices.
Reference: Bingbing Yang et al, Engineering relaxors by entropy for high energy storage performance, Nature Energy (2023). DOI: 10.1038/s41560-023-01300-0