Bioinspired Polymer Nanocomposites Exhibit Giant Energy Density and High Efficiency at High Temperature

Abstract

Polymer dielectrics are ubiquitous in advanced electric energy storage systems. However, the relatively low operating temperature significantly menaces their widespread application at high temperatures, such as for hybrid vehicles and aerospace power electronics. Spider silk, a natural nanocomposite comprised of biopolymer chains and crystal protein nanosheets combined by multiple interfacial interactions, exhibits excellent mechanical properties even at elevated temperatures. Inspired by the hierarchical nanostructure of spider silk, poly(aryl ether sulfone) is anchored to the surface of wide bandgap artificial nanosheets to prepare the nanocomposites with nanoconfinement effect. The bioinspired strategy successfully improves the mechanical and electrical performances of the nanocomposite. Owing to the structural‐enabled enhancements, the nanocomposites exhibit excellent breakdown strength and electrical energy storage performance at high temperatures. In detail, giant discharged energy density (2.7 J cm−3) and high charge–discharge efficiency (>90%) are simultaneously achieved at 150 °C and 400 MV m−1. Notably, under 500 MV m−1, the discharged energy density reaches 4.2 J cm−3, which is the record high discharged energy density among polymer‐based dielectrics at 150 °C. This work demonstrates a viable strategy to design high‐temperature polymer dielectrics by constructing nanoconfinement in the nanocomposites.

Tuning Nanofillers in In Situ Prepared Polyimide Nanocomposites for High‐Temperature Capacitive Energy Storage

“…To address these imperative needs, a variety of well‐established engineering polymers, including polycarbonate, polyimide (PI), polyetherimides, and poly(ether ether ketone), have been exploited as high‐temperature dielectric materials. [ 19–25 ] As these aromatic polymers have high glass transition temperatures ( T g ) and excellent thermal stability, it is anticipated that the engineering polymers would retain electromechanical properties and thus dielectric stability at high temperatures. However, when subjected to high applied fields, the engineering polymers exhibit limited working temperatures that are much lower than their T g s. [ 19,20 ] More recently, inorganic fillers represented by boron nitride nanosheets (BNNSs) have been incorporated into crosslinked divinyltetramethyldisiloxane‐bis(benzocyclobutene) ( c ‐BCB) to yield the dielectric polymer composites capable of operating efficiently at high temperatures, e.g.…”

Interface‐Strengthened Polymer Nanocomposites with Reduced Dielectric Relaxation Exhibit High Energy Density at Elevated Temperatures Utilizing a Facile Dual Crosslinked Network

“…Currently, conventional dielectric materials, including inorganic ceramics (e.g., BaTiO 3 (BT)) and polymers (e.g., biaxially oriented polypropylene (BOPP)) have been proven to be successful in developing technologies that meet our daily life, [ 10,11 ] while higher demands are being called to develop new dielectric capacitors for achieving miniaturization and weight reduction, and then operate in extreme environments, such as the avionics and automotive industries, [ 12 ] underground oil and gas explorations, [ 13 ] and advanced propulsion systems. [ 14 ]…”

Polymer/molecular semiconductor all-organic composites for high-temperature dielectric energy storage

“…Recent studies demonstrate that insulating, inorganic nanostructures (e.g., boron nitride nanosheets) can be utilized to impede the transport of charge carriers in dielectric polymers [14][15][16][17][18] . The resultant polymer nanocomposites show improved capacitive performance at elevated temperatures, achieving concurrent high U e (varying from 2.2 to 4.8 J cm −3 ) and high η (~90%) up to 150°C.…”

“…Such performance falls well short of the requirement for conversion and control of electrical energy in many of the emerging applications ranging from distributed power converters in electrified aircraft to electrical compressors in deep oil and gas extraction [3][4][5]7 , where the operating temperature can reach or exceed 200°C. Moreover, the insulating nanostructures [14][15][16][17] are synthesized in low yields (e.g., nanosheets and nanowires), have high surface energies (i.e., unsatisfactory compatibility with polymers), and are loaded at high concentrations (c.a. 10 vol.%), rendering the manufacture of largearea and uniform nanocomposite films challenging 19 .…”