Constructing Novel High-Performance Dipolar Glass Polymer Dielectrics by Polar Rigid/Flexible Side Chains

Abstract

Developing new polymer dielectrics with superior dielectric and energy storage properties is urgent to meet the demand for electronic devices in the field of microminiaturization or harsh environments. In this paper, two dipolar glass polymers based on polynorbornene main chain and flexible/rigid cyano side chain were synthesized by ring opening metathesis polymerization method: polymer PCEMT with flexible side chains and polymer PCPMT with rigid side chains. The backbone is built from two rigid five-membered rings, which not only avoids the narrow band gap caused by π−π conjugation of traditional aromatic main chains, but also maintains high thermal stability and high glass transition temperature (T g ). The introduced polar cyano groups on the side chain gave high dielectric constants (ε r ) for both polymers, where the ε r of PCEMT and PCPMT reached 7.9 and 4.6 at room temperature and 1 kHz, respectively. Due to high polarization and high breakdown strength, the PCPMT obtains a maximum discharge energy density (U d ) of 4.47 J/cm 3 at room temperature, which is 1.61 and 1.57 times of biaxially oriented polypropylene and polyimide (Kapton). The supernal T g of 229 °C makes the energy storage performance of PCPMT almost unaffected at 100 °C. The charge−discharge efficiency (η) always keeps over 90% and an U d of 5.2 J/cm 3 at 480 MV/m is achieved, which is much better than Kapton (U d = 1.77 J/cm 3 , η = 42.5%) under the same conditions. This work provides a new idea for preparing the high-performance polymer dielectrics via introducing rigid polar side chains.

Engineering Poly(phthalazinone ether sulfone) Dielectric Films for Stable High-Temperature Capacitive Energy Storage

“…Generally, the larger band gaps could retain higher breakdown strength in polymers. However, previous literature results indicated that in addition to the band gap, Young’s modulus and leakage current density also have an impact on the breakdown strength …”

“…Meanwhile, comparing the density of states between the PPES and the PSF (Figure a), it can be noticed that PPES had a smaller LUMO energy level; therefore, the electron affinity of PPES was greater. This heightened electron affinity may limit the movement of electrons along the main chain during charge injection, resulting in significantly smaller leakage current density for PPES compared to PSF . In other words, the conduction loss of PPES was below that of PSF.…”

Research on the energy storage performance of laminated composites based on multidimensional co-design in a broad temperature range

“…12 The large volume proportion and use of additional cooling systems due to polymer limitations are not in line with the modern design concept of light weight and efficient energy-storage capability. [13][14][15] Therefore, there is an urgent need to develop polymer dielectrics that can provide both high temperature stability and high energy storage performance.…”

Enhanced Energy Storage in PVDF-Based Nanocomposite Capacitors through (00l)-Oriented BaTiO3 Single-Crystal Platelets

“…Dielectric capacitors, as energy storage devices, offer distinct advantages including high power density, rapid charge–discharge capability, and durability. − These performances make dielectric capacitors indispensable in the fields of electrical defibrillators, electrically launched weapons, and hybrid electric vehicles (HEV). − However, the relatively low energy storage density ( U e ) of dielectric capacitors significantly restricts their widespread application in the mentioned fields. Commercialized biaxially oriented polypropylene (BOPP), among the most representative flexible energy storage materials, exhibits a U e of only ∼2 J cm –3 , whereas commercial electrochemical capacitors have U e 's of up to 20 J cm –3 .…”