Polyetherimide Nanocomposites Research Articles

Roll-to-Roll Manufactured Polyetherimide Nanocomposite With Different Diameters of SiO2 Nanoparticles Exhibiting Improved High-Temperature Dielectric Energy Storage Performance.

To enhance the high-temperature energy storage performance of the polymer-based dielectric film, inorganic nanofillers with large band gaps are much more effective and have been widely adopted. However, the impact of nanoparticle diameters on the dielectric properties of polymer nanocomposites has been less studied. Herein, silicon dioxide nanoparticles (SiO2-NPs)with varying diameters (20, 60, 120, 200nm) prepared by the sol-gel method are incorporated in the PEI matrix to form PEI/SiO2 nanocomposites. The characterization results reveal a distinct correlation between the dielectric properties of polyetherimide (PEI) composites and the diameters of SiO2-NPs. Leakage current density analysis and breakdown strength simulations indicate that SiO2-NPs with smaller diameters generate more deep traps that impede the transport of charge carriers, especially under high temperatures. Notably, PEI/20nm-SiO2 exhibits a high discharged energy density of 4.4 J cm-3 with an efficiency of 90% at 150°C. Furthermore, PEI/SiO2 films with 10µm in thickness are manufactured by a large-scale solution casting process. The continuously prepared PEI/20nm-SiO2 film exhibits a discharged energy density of 3.2 J cm-3 with an efficiency of 90% at 150°C. This study not only provides a strategy for the design of high-performance dielectric polymer composites but also offers a large-scale high-temperature dielectric film for practical use.

Polyimide-coated MgO nanoparticles improves high-temperature energy storage performance in polyetherimide-based nanocomposite films

Enhancing the energy storage capacity of dielectric polymers can be achieved by the introduction of inorganic nanoparticles. However, the difference in surface energy often influences the interfacial compatibility of nanoparticles with polymers, consequently limiting their comprehensive dielectric properties. Here, the magnesium oxide (MgO) nanoparticles were coated with polyimide (PI) shells via in-situ polymerization, which is beneficial to improve the scattered particles in the polyether imide (PEI) matrix. The PI buffer shell is tightly bound to the PEI matrix through automatic electrostatic interaction making the defects decrease, together with the increased dielectric permittivity (εr) attributed to MgO, significantly enhancing the discharged energy density (Udis) and storage efficiency (η) of the PI@MgO/PEI nanocomposite films in harsh conditions. Thus, the maximal Udis of the PI@MgO/PEI nanocomposites is 4.33 J/cm3 at 150 °C, twice that of the pristine PEI. Even if an η exceeds 90 %, the Udis of 3.83 J/cm3 of 1 vol%-PI@MgO/PEI at 500 MV/m and 150 °C is better than that of the most advanced dielectric polymers.

High-temperature high-performance capacitive energy storage in polymer nanocomposites enabled by nanostructured MgO fillers

High-temperature high-performance polymer dielectric capacitors are essential for cutting-edge electronics and high-power systems operated in harsh environment conditions. Herein, dielectric composites comprising polyetherimide (PEI) polymers and easily prepared magnesium oxide (MgO) nanoparticles are fabricated by tape casting to promote capacitive performance at high temperatures. Benefiting from high-insulation behavior and wide bandgap of the MgO nanoparticles, the designed PEI nanocomposites deliver the significantly suppressed leakage current density and prominent enhancement of the breakdown strength, especially under high temperatures, the rationality of which is further revealed by finite element simulations on high-field distribution and electrical tree evolution. Accordingly, the nanocomposites containing ultra-low loading volume (0.5 vol%) MgO nanoparticles endow a large discharged energy density (~ 6.60 J cm−3) at 150 °C, which is ahead of most investigated 0–3 dielectric nanocomposites with inorganic fillers. Moreover, the excellent fatigue resistance at 150 °C is simultaneously achieved. This study demonstrates a practical route to develop scalable high-temperature polymer nanocomposite dielectrics blended with inorganic nanoparticles with superior capacitive performance, thus accelerating the development of dielectric polymer capacitors.

Significantly enhanced electrostatic energy storage performances of polyetherimide nanocomposites with ultralow loadings of barium titanate nanoparticles

Significantly enhanced electrostatic energy storage performances of polyetherimide nanocomposites with ultralow loadings of barium titanate nanoparticles

Polyetherimide nanocomposite with enhanced mechanical, thermal and dielectric properties by incorporating synergistically exfoliated‐chemical functionalization induced hexagonal boron nitride nanosheets

AbstractThe present study aims to improve the mechanical, thermal and dielectric properties of polyetherimide (PEI) nanocomposite via simplified method, involving the creation of a nanocomposite using PEI incorporated with exfoliated‐chemical functionalization induced hexagonal boron nitride nanosheets (BNNS). XRD, FTIR and Raman elucidated the chemical structure of functionalized BNNS and indicated the success preparation of functionalized BNNS. Functionalization effectively improved the compatibility of nanocomposites and contributed to the property improvements. Morphological analysis unveiled a compact and dense microstructure within the nanocomposites in correlation with functionalized BNNS. Broad band dielectric spectroscopy revealed excellent dielectric properties of produced PEI nanocomposite. DMA testing verified a noteworthy enhancement in both Tg and storage modulus upon incorporating of BNNS. In summary, this comprehensive investigation highlights the impact of functionalized BNNS on mechanical, thermal and dielectric properties of developed PEI dielectric nanocomposite and is expected to expand the application of PEI in the field of high‐temperature energy storage.Highlights Polyetherimide (PEI) was used as polymer matrix and boron nitride derivatives as dielectric fillers to prepare PEI dielectric nanocomposite. Due to the influences of dielectric properties by interface polarization effect and the local distribution of electric field of the fillers in PEI matrix, the dielectric constant, breakdown strength and energy storage density of PEI nanocomposites were obviously improved compared with pure PEI. The effects of interfacial interactions between PBNNS and PEI contributes to the uniform dispersion and comprehensive property improvements of PEI dielectric nanocomposites. This work presents a systematic investigation into the fabrication of PEI/BNNS nanocomposite using a one‐step solution blending method, inspiring the research and development of PEI in the energy storage applications areas in the future.

High temperature electrical breakdown and energy storage performance improved by hindering molecular motion in polyetherimide nanocomposites

Polyetherimide (PEI) is widely used as a material for high temperature and high power energy storage capacitors in new energy vehicles and other fields. However, as the temperature increases, the electrical conductivity increases and the breakdown strength decreases, which greatly reduces the energy storage density of the capacitor and limits the application range. In order to clarify the influence mechanism of high temperature on the breakdown and energy storage performance of dielectrics, this paper established a charge capture and molecular displacement (CTMD) breakdown model based on the expansion motion of molecular segments to study the charge transport and molecular chain motion process of PEI nanocomposites (PNCs) at high temperature. The results show that at 100 °C, compared with pure PEI, the internal maximum molecular displacement of PEI PNCs with appropriate doping content (3 wt%) is reduced by 28.79 %, and the breakdown strength is increased by 11.20 %. Appropriate nano-doping can effectively increase the movement difficulty of molecular chains and reduce the activation volume that provides energy for charge transport. Thus, charge transport is inhibited, current density is reduced, and Joule heat accumulation is avoided. Finally, the high temperature breakdown and energy storage performance are improved.

In situ polymerized polyetherimide/Al2O3 nanocomposites with significantly improved capacitive energy storage performance at high temperatures

High-temperature polymer nanocomposites with high energy storage density (Ue) are promising dielectrics for capacitors used in electric vehicles, aerospace, etc. However, filler agglomeration and interface defects at high filler loadings significantly limit the enhancement of Ue and hamper the large-scale production of the nanocomposites. Here, polyetherimide (PEI) nanocomposites with nanoscale alumina (AO) at ultra-low contents were prepared via in situ polymerization from PEI monomers. We compared two composite dielectric preparation methods (in situ polymerization and ordinary solution blending) under the same conditions. In contrast to the nanocomposites obtained by blending PEI polymers with AO, the in situ nanocomposites exhibit substantially improved filler dispersion, together with largely suppressed conduction loss at high fields and high temperatures, leading to comprehensive enhancements of breakdown strength (Eb), charge-discharge efficiency (η) and Ue, simultaneously. The 0.3% (in volume) AO filled PEI nanocomposite film exhibits a superior Ue of 4.8 J/cm3 with η of 90% at 150 °C, which is 128% and 218% higher than those of pristine PEI and the ex situ PEI/AO nanocomposite film under the same conditions, respectively. This work provides a scalable strategy for the preparation of dielectrics with both good processability and excellent high-temperature energy storage performance.

Energy storage density and efficiency of polyetherimide nanocomposites diminished by the temperature dependent charge hopping

AbstractThe utilization of renewable energies requires extensive use of energy storage equipment such as dielectric capacitor. Polyetherimide nanocomposites (PEI PNCs) have high energy storage performance, and become the next generation advanced dielectrics However, the quantitative relation between the charge transport and energy storage of PEI PNCs is not very clear, restricting further improvement of their performance. Considering the charge injection from electrodes and the charge hopping transport inside the dielectric, the energy storage and release model of capacitors was established. Firstly, the conductivities of PEI PNCs were simulated, and the charge transport parameters were determined by comparing with the experiments. Then, the electric displacement‐electric field (D‐E) loops of PEI PNCs were simulated, and the discharged energy density and energy efficiency were calculated from them. The simulation results are consistent with the experiments, and the quantitative relationship between charge injection and transport parameters and energy storage performance is established. In addition, it is found that the energy storage density and efficiency are diminished by the increase of hopping distance at high temperatures. Increasing the hopping barrier, reducing the hopping distance and its temperature dependence through nano‐doping can significantly improve the energy storage performance under high temperatures and high electric fields.

Mesoscopic trap and elastic properties of polyetherimide nanocomposites with improved energy storage performance

Polymer nanocomposites (PNCs) are important energy storage dielectrics for capacitors. However, the lack of quantitative research on the properties of mesoscopic scale conductivity, traps, and Young's modulus in interfacial regions between polyetherimide and nanofillers results in an unclear understanding of the relation between the structure and properties. Polyetherimide/Al2O3 PNCs are prepared by in-situ polymerization, and the dielectric, thermal, and mechanical properties are measured. The experiments show that the film doped with 3 wt% nanofillers has the highest resistivity, Young's modulus, breakdown strength, and energy storage density. Then, the mesoscale distributions of the conductivity and Young's modulus in interfacial regions are solved as the inversion problem of electric and stress fields, and the macroscopic conductivity and Young's modulus of PNCs are obtained by high-throughput simulations. The conductivity, trap, and Young's modulus distributions are obtained by comparing the simulation and experimental results. It shows that the molecular chains in interfacial regions are bounded by nanofillers to form a tighter aggregated structure, hindering the molecular motion. Accordingly, the charge transport between molecular chains slows down, the trap energy increases and the conductivity decreases. The tighter aggregated structure makes PNCs have higher breakdown strength, energy storage density, and lower energy loss.

Excellent high-temperature energy storage capacity for polyetherimide nanocomposites with hierarchically structured nanofillers

High-temperature electronic power systems need reliable dielectric energy storage materials, but conductive losses in extreme conditions impair their performance. Hierarchically-structured fillers are promising to not only integrate the benefits of diverse components but also effectively utilize interface engineering and electron scattering effects to optimize dielectric and breakdown properties, thereby modulating energy storage performance in polymer-based composites. In this work, we successfully fabricated hierarchical nanofillers comprising 2D boron nitride nanosheets (BNNS) and 0D ultrafine strontium titanate (ST) nanoparticles. The paraelectric ceramic ultrafine ST possesses a high dielectric constant and low residual polarization, which enhances the energy storage density of composite materials while ensuring high conversion efficiency. The PEI-based nanocomposites loaded with hierarchical BNNS@ST nanofillers attain remarkable discharged energy density (4.29 J cm−3) and charging and discharging efficiency (η > 80%) at 150 °C. This approach utilizing hierarchically-structured nanofillers offers a feasible strategy to explore high-energy–density polymer dielectrics applied in extreme environments.

Enhanced Interfacial and Dielectric Performance for Polyetherimide Nanocomposites through Tailoring Shell Polarities

Polyimide (PI) and its derivative polyetherimide (PEI) have been widely investigated as promising candidates for dielectric energy storage due to their excellent intrinsic features. However, most of the current research for PI- or PEI-based dielectric nanocomposites only focuses on a certain polar group contained in a dianhydride monomer, while there are very few studies on exploring the effect of a series of polar groups derived from various dianhydride monomers on the dielectric properties of nanocomposites. To fill this gap, we herein fabricated and investigated a series of novel hyperbranched polyimides grafted on barium titanate nanoparticles (HBPI@BT) using different dianhydride monomers and their nanocomposites with the PEI matrix. The results showed that sophisticated hyperbranched structures effectively alleviated the incompatibility between fillers and the matrix, thus significantly improving the bonding energy of nanocomposites, especially for HBPI-S@BT/PEI (797.7 kJ/mol). The Ud of HBPI-S@BT/PEI reached 8.38 J/cm3, which is 3.3 times higher than that of pure PEI. The HBPI-F@BT/PEI nanocomposites achieved high breakdown strength (∼500 MV/m) and low dielectric loss (0.008) simultaneously. The dielectric constants of HBPI@BT/PEI nanocomposites remained at a stable level from 25 to 150 °C. This work provides us promising hyperbranched structured materials for potentially advanced dielectric applications such as field effect transistors.

Improved Capacitive Energy Storage Nanocomposites at High Temperature Utilizing Ultralow Loading of Bimetallic MOF.

It is urgent to develop high-temperature dielectrics with high energy density and high energy efficiency for next-generation capacitor demands. Metal-organic frameworks (MOFs) have been widely used due to their structural diversity and functionally adaptable properties. Doping of metal nodes in MOFs is an effective strategy to change the band gap and band edge positions of the original MOFs, which helps to improve their ability to bind charges as traps. In this work, the incorporation of ultralow loading (<1.5 wt%) of novel bimetallic MOFs (ZIF 8-67) into the polyetherimide (PEI) polymer matrix is exhibited. With the addition of ZIF 8-67, the breakdown strength and energy storage capacity of ZIF 8-67/PEI nanocomposites are significantly improved, especially at high temperatures (200 °C). For example, the energy densitiy of the 0.5 wt% ZIF 8-67/PEI nanocomposite is up to 2.96 Jcm-3 , with an efficiency (η) > 90% at 150 °C. At 200 °C, the discharge energy density of 0.25 wt% ZIF 8-67/PEI nanocomposites can still reach 1.84 Jcm-3 with a η> 90%, which is nine times higher than that of pure PEI (0.21 Jcm-3 ) under the same conditions, and it is the largest improvement compared with the previous reports.

Enhanced energy density in polyetherimide nanocomposite film at high temperature induced by electrospun BaZrTiO3 nanofibers

Enhanced energy density in polyetherimide nanocomposite film at high temperature induced by electrospun BaZrTiO3 nanofibers

Ultra-superior high-temperature energy storage properties in polymer nanocomposites via rational design of core–shell structured inorganic antiferroelectric fillers

Polyetherimide nanocomposites with core–shell structured (Pb, La)(Zr, Sn, Ti)O3@Al2O3 antiferroelectric nanoparticle fillers deliver an ultra-high discharged energy density of 10.2 J cm−3 and a large efficiency of 83.5% at 150 °C.

Regulation of Interfacial Polarization and Local Electric Field Strength Achieved Highly Energy Storage Performance in Polyetherimide Nanocomposites at Elevated Temperature via 2D Hybrid Structure

AbstractDielectric materials with excellent high‐temperature energy storage performances are urgently demanded in advanced electronic market. However, the sharply reduced energy storage capabilities caused by conduction loss impede the applications of polymer‐based nanocomposites at harsh environments. In this work, the 2D hybrid structure fillers of boron nitride nanosheets‐titanium dioxide (BNNSs‐TiO2), where TiO2 nanoparticles tightly wrap around the 2D BNNSs, are fused with polyetherimide (PEI) forming polymer nanocomposite films. The finite element simulation and experiment results indicate that the hybrid structure 2D BNNSs‐TiO2 can effectively regulate local electric field strength and interfacial polarization, facilitating the enhancement in energy storage properties. Accordingly, the composite film delivers a superior discharged energy density (≈4 J cm−3) and charging/discharging efficiency (≈90%) at 150 °C, better than recently discussed high‐temperature pristine polymer and their composite films. This contribution offers a feasible idea to explore reliable dielectric capacitors at high temperature.

Improved breakdown strength and energy storage performances of PEI-based nanocomposite with core-shell structured PI@BaTiO3 nanofillers

High dielectric constant (εr) inorganic nanoparticles reinforced dielectric polymer nanocomposites have been intensively investigated for energy storage applications in current electrical and electronic systems. Although the incorporation of high-εr inorganic nanoparticles can improve the εr of the composites to a certain extent, it will also greatly reduce the overall breakdown strength (Eb) of the materials, which ultimately hinders the effective improvement of the energy storage density of the composites. In this paper, an approach is developed to modify high-εr BaTiO3 (BTO) nanoparticles with polyimide (PI) polymer shells (PI@BTO) through an in-situ polymerization process in the polyetherimide (PEI)-based nanocomposites. The constructed PI shell improves the compatibility of the inorganic/organic interface, resulting in a uniform dispersion of nanoparticles in the PEI matrix. In particular, the spontaneous electrostatic interaction between polymer chains in the PI shell and PEI matrix enables an increased Eb of the PEI/PI@BTO nanocomposite over the pure PEI, which leads to a high energy storage density (Ue) of 6.2 J/cm3 and a high charge-discharge efficiency (η) above 80% in the PEI nanocomposites, with an enhancement of 150% over pure PEI. In this paper, a convenient and efficient interfacial modification technique is provided for the development of flexible high energy storage density polymer/inorganic nanoparticle composites for dielectric and energy storage applications.

Extremely low loading of carbon quantum dots for high energy density in polyetherimide nanocomposites

• Functionalized CQDs were synthesized, which showed monodispersity in solvent. • Coulomb-blockade effect of CQDs was utilized to increase the E b of PEI matrix. • The composite with 0.5 wt% CQDs exhibited a high U e of 10.66 J/cm 3 at 600 kV/mm. There is an urgent need for dielectric capacitors with high energy density and efficiency with the rapid progress of power electronic devices. Inorganic/organic composites were once considered as a potential candidate for dielectrics. However, the inevitable defects induced by the inorganic fillers always lead to the decreased breakdown strength and limited energy density and efficiency. In this work, carbon quantum dots (CQDs) with abundant functional groups were synthetized and introduced into linear dielectric polyethyleneimine (PEI) matrix. Due to the unique Coulomb-blockade effect of quantum dots, the movement of carriers can be hindered under the applied electric field, leading to the improvement of breakdown strength. Compared with most of the reported nanocomposites with high loading of fillers, the nanocomposites in this work with extremely low loading of CQDs exhibit obviously enhanced performance. The nanocomposite with 0.5 wt% CQDs exhibits a high discharge energy density of 10.66 J/cm 3 and efficiency of 88.3% at 600 kV/mm, corresponding to a 62.3% improvement over that of PEI (6.57 J/cm 3 at 490 kV/mm). This work provides an effective strategy to break down the long-standing contradiction between the enhancement of dielectric constant and the reduced in breakdown strength. The film dielectrics with extremely low loading of fillers contributing to enhanced energy density and high energy efficiency is very important for practical applications.

Modulating the charge trapping characteristics of PEI/BNNPs dilute nanocomposite for improved high-temperature energy storage performance

The incorporation of an ultralow volume fraction of boron nitride nanoparticles can modulate the charge trapping characteristics of polyetherimide nanocomposites, leading to improved high-temperature energy storage performances.

Largely enhanced dielectric properties of polymer composites with HfO2 nanoparticles for high-temperature film capacitors

Polymer dielectrics are preferred materials for high-energy-density capacitive energy storage. In particular, high-temperature dielectrics that can withstand harsh conditions, e.g., ≥150 °C, is of crucial importance for advanced electronics and electrical power systems. Herein, high-temperature dielectric polymer composites composed of polyetherimide (PEI) matrix and hafnium oxide (HfO2) nanoparticles are presented. It is found that the incorporation of HfO2 with a moderate dielectric constant and a wide bandgap improves the dielectric constant and simultaneously reduces the high-field leakage current density of the PEI nanocomposites. As a result, the PEI/HfO2 composites exhibit superior energy storage performance to the current high-temperature engineering polymers at elevated temperatures. Specifically, the nanocomposite with 3 vol% HfO2 displays a discharged energy density of 2.82 J/cm3 at 150 °C, which is 77% higher than neat PEI. This work demonstrates the effectiveness of incorporation of the nanofiller with a medium dielectric constant into the polymer on the improvement of high-temperature capacitive properties of the polymer composites.

Development and characterization of organoclay filled polyetherimide nanocomposites for anticorrosive coatings

Abstract Polyetherimide (PEI)/organically modified Fluorohectorite (OFH) nanocomposite were prepared by dispersing OFH in PEI matrix. The structural as well as morphological characteristics of the nanocomposites were investigated using X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and Transmission Electron Microscopy (TEM). The thermal and mechanical properties of the PEI nanocomposites were found to be significantly improved by the incorporation of organically modified flurohectorite nano clay into the PEI matrix. The water uptake of the nanocomposites was investigated in detail as a function of clay content and it was minimum for composites with 3 wt% of filler. The anticorrosion properties of clay polymer nanocomposite (CPN) coatings were evaluated by means of various electrochemical methods which include Electrochemical Impedance Spectroscopy (EIS) and Open Circuit Potential Measurements (OCP). The results obtained from various analyses showed that the PEI/OFH nanocomposites coatings possess better anticorrosion properties.