Sandwich-structured SBS/PEI nanocomposites regulate charge, heat and mechanics. SiO 2 aerogel suppresses charge injection and heat transfer, while BT–BNT–CZ boosts polarization and deep traps, achieving 6.94 J cm −3 at 200 °C with 90% efficiency.

The growing demand for wearable electronics and the Internet of Things (IoT) calls for flexible piezoelectric energy harvesters with substantially improved power output. Polyacrylonitrile (PAN) polymers, with their high polarization and excellent thermal stability, are among the most promising candidates for efficient flexible piezoelectric materials. However, the performance of existing PAN-based harvesters remains limited, and strategies for further enhancing their output are still insufficiently explored. Herein, this study aims to overcome the output bottleneck of PAN-based PENGs by implementing a novel mechanical excitation strategy. Using electrospun flexible PAN-BaTiO3 nanocomposite films, we systematically compared the electromechanical responses under conventional compression and impact modes. Real-time synchronized force-current measurements in compression mode revealed that the output current increases progressively with drive frequency (2-10 Hz). Specifically, the PENG with PAN-20 wt.% BaTiO3 achieved a peak current of 0.33 mA at 10 Hz, showing an approximately 7.9-fold enhancement over its pure PAN counterpart. More importantly, under 6 Hz impact excitation, the device exhibited a remarkable output current density of 1.0 mA cm-2 and a peak power density of 256.5 µW cm-2. This current density is 95 times higher than that in compression mode at a comparable frequency and surpasses the performance of most recently reported piezoelectric and triboelectric nanogenerators. With an effective area of 16 cm2, the PENG could simultaneously illuminate up to 275 commercial LEDs or 100 individual bulbs and maintained stable operation over 63,530 cycles. This work overcomes the output bottleneck in low-frequency energy harvesting and provides an effective pathway toward practical energy-harvesting applications.

Improving the output power of piezoelectric nanogenerators (PENGs) is currently the most urgent task to promote their practical application toward next-generation flexible electronics and distributed sensor devices for an environmentally sustainable society. Despite considerable performance progress through sophisticated material design and elaborate structure optimization, the frequency mismatch between mechanical energy sources in natural scenario and the PENG device remains a crucial issue causing low energy conversion efficiency. Herein, we propose a unique mechanical excitation pattern that employs a spring-induced impact force applied to electrospun flexible BaTiO3/PVDF nanocomposite film to maximize the output power of PENG. Compared with the conventional compression mode, this instantaneous stress ejection effectively reduces the force response time from 6.0 to 0.5 ms to achieve frequency up-conversion, as evidenced by a real-time synchronized force-current curve. Moreover, the impact force enhances the separation of positive and negative polarity of the piezoelectric electron cloud and contributes to generating more piezoelectric charges. Consequently, the output current and power density are significantly elevated by 40.0 and 2013.7 times to 1.04 mA cm-2 and 322.2 mW cm-2, respectively, far surpassing recent reported PENG and triboelectric nanogenerators TENG. Surprisingly, a 16 cm2 PENG can light up 2000 LEDs and nine bulbs in a record-breaking, and stable operation with 63 530 cycles. Finally, a wireless temperature and humidity sensing has been successfully demonstrated through PENG's power supply, proving its actual IoT application capability. This study developed a universal and effective impact excitation strategy to enhance the output power of PENG, which is expected to be integrated with more high-piezoelectric coefficient materials to break through performance bottlenecks in low-frequency energy harvesting, thereby promoting the practical application of PENG's energy technology.

High-temperature polymer dielectrics must meet the requirements of modern power electronic systems, particularly high energy storage density under elevated-temperature conditions. However, polyetherimide (PEI), one of the most promising candidate materials, suffers from significant deterioration in energy storage density due to high conductive loss under high temperatures. In this study, we designed a polymer alloy comprising PEI and semi-aromatic benzimidazole polyimide (SPBII), where intermolecular hydrogen bonding acts as a compatibilizer to stabilize a nanoscale microphase-separated structure. The SPBII polymer chains confined within nanoregions exhibit a nanoconfinement effect, substantially enhancing the thermal and mechanical properties of the polymer alloy, with Tg and Young's modulus of 50% SPBII reaching 287.5°C and 5.32 GPa. Furthermore, the high positive electrostatic potential of SPBII introduces charge traps at the PEI/SPBII interface, effectively suppressing high-temperature conduction loss. As a result, the 50% SPBII polymer alloy demonstrates remarkable improvements in breakdown strength and energy storage density. For instance, at 200°C, it achieves an energy density of 4.53 J cm-3 with an efficiency of 90%, outperforming that of pure PEI (1.71 J cm-3). This breakthrough provides a promising solution for achieving superior capacitive performance of dielectrics under high-temperature conditions, significantly advancing the applications of polyimide-based dielectric materials.

Polymer films capacitors are widely used in the electrical and electronic fields, and much effort has been devoted to exploiting the high temperature resistant polymer dielectrics with superior discharged energy density (Ud) and efficiency (7) in harsh environments. The addition of organic molecular fillers is good way to improve the energy storage properties of dielectric polymers. In this work, for the first time, the host organic filler (methyl beta-cyclodextrin, M-beta-CD) is embedded into the guested polynorbornene dielectrics containing amantadine side-chain (PATMD). All-organic polymeric dielectric composites (M-beta-CD/PATMD) is obtained based on the host-guest interaction between PATMD matrix and M-beta-CD filler. The experiment results showed that the introduction of host filler can obviously enhance the Ud and 7 at high temperature and high field because inclusion complex can simultaneously increase thermal performance and trap depth. The maximum Ud of 0.1 wt% M beta-CD/PATMD is 7.4 J/cm2, maintaining the 7 of above 90 %. Importantly, at 150 degrees C and 200 degrees C, the largest Ud of 4.3 J/cm2 and 3.6 J/cm2 is achieved respectively, and the corresponding 7 is 80 % and 74 %, which is both much higher than that of pure PATMD. This work proves that the cyclodextrin-based host-guest design method is a good effective strategy for the preparation of high performance polymer dielectrics.

In this work, we introduce a high entropy effect in designing a relaxor ferroelectric (RFE)–antiferroelectric (AFE) crossover ceramic by incorporating a high entropy relaxor-like oxide (Pb0.25Ba0.25Sr0.25Ca0.25)TiO3 with antiferroelectric NaNbO3. The results show that the relaxor ferroelectricity of the system is enhanced with increasing NaNbO3, and when the new composition reaches the highest configurational entropy, stable energy storage properties can be achieved. This is enabled by a high breakdown strength due to the small grain size and stable slim ferroelectric hysteresis loop with high efficiency due to entropy-stabilized short-range ordered polar nanoregions (PNRs). These findings showcase the potential of this strategy for exploiting new compositions of high-performance electrostatic capacitors.

State-of-the-art studies have promoted the output energy density of triboelectric nanogenerators (TENGs) to 105 J m-3, while the current major barrier lies in the breakdown discharge limit. Universal performance metrics that reveal the maximized energy output ability of TENG approaching the breakdown limit are highly desirable but remain a major challenge. Herein, this work proposed performance metrics for charge density and output energy density, quantitatively characterizing the output performance based on a sliding-freestanding TENG with the charge excitation strategy. A series of parameters of different dielectric materials was systematically investigated to reveal their impacts on the performance metrics. Consequently, the maximum output energy density of 10 kinds of tribo-dielectrics was evaluated based on the voltage-charge (V-Q) curve, validating the proposed performance metrics. Guided by this new standard, we developed a stretched poly(vinylidene fluoride-co-trifluoroethylene) (P(VDF-TrFE)) film with synergistically improved permittivity and breakdown strength, achieving a record-high charge density and output energy density of 2.8 mC m-2 and 6.2 x 105 J m-3, respectively. Furthermore, a self-driven charge excitation system was explored in rotary-mode TENGs, showing excellent output capability to directly light up 15 series bulbs. This work establishes a basic standard and guideline for improving the energy output of TENGs, highlighting their potential applications for energy harvesting.

Improving the high-temperature performance of polymer dielectrics is critical for the development of advanced electrical systems. The deterioration of the capacitive performance of polymer dielectrics at high electric fields and elevated temperatures is attributable to the exponentially increased conduction loss. Herein, a synergistic strategy of molecular trap and aggregation structure optimization is developed to suppress the conduction loss of polymer dielectrics. A molecular semiconductor - HAT-CN with high electron-affinity (EA) and special distribution of electrostatic potential is designed in this work. The theoretical calculation and experimental results show that HAT-CN can introduce electron traps and simultaneously interrupt the conjugation between aromatic rings in molecular chains via electrostatic interaction with polyetherimide (PEI). Consequently, the collective effect of electron trap and aggregation structure optimization reduces the leakage current density of PEI by nearly an order of magnitude at 200 degrees C and improves the mechanical properties of films. Finally, the HAT-CN/PEI all-organic composite achieves a discharge energy density of 3.8 J cm(-3) with efficiencies above 90% (U eta>90%) and long-term reliability over 100 000 cycles at 200 degrees C, outperforming most current polymer dielectrics. This work provides a new idea for the design of high-temperature polymer dielectrics based on molecularly engineered organic semiconductors.

High-performance dielectric capacitors are in great demand for high-power energy storage applications. HfO2based films have drawn considerable interest in on-chip integration for microelectronics owing to their ultrathin thickness, complementary-metal-oxide-semiconductor (CMOS) compatibility, and excellent polarization adjustability. Herein, we present Hf0.5Zr0.5O2(3):ZrO2(12) (HZZ)-based films with a heterogeneous structure combined with a high temperature (HT) deposited HZZ layer and a low temperature (LT) deposited HZZ layer by regulating their thickness. The increased thickness of LT-HZZ allows for the alteration of the internal crystal structure and the tuning of electrical behaviors, and thus promoting the improvement of breakdown strength. The existence of HT-HZZ layer can sustain the dielectric constant of the entire structure at a rather elevated level and ensure the stability of polarization. An ultrahigh discharged energy density (ESD) of 122.04 J/cm3 along with an efficiency of 64.02 % is achieved at an electric field of 10.29 MV/cm in the HT1-LT3 film, as well as a fatigue performance of 108 cycles. The design strategy utilizing hierarchically-structured films constitutes a fresh way for attaining remarkable performance in HfO2-based energy storage microsystems.

MnO2-doped Ca0.97Bi2.03Nb2O9 ceramics with greatly improved piezoelectric performance were prepared via conventional solid state sintering method. The effects of MnO2 doping on the microstructure and electrical properties of Ca0.97Bi2.03Nb2O9 ceramics were studied. X-ray diffraction (XRD) analysis and Rietveld refinement revealed a reduction in orthorhombicity with MnO2 doping, which contributed to the enhancement of the piezoelectric properties. Furthermore, the introduction of MnO2 lowered the sintering temperature, thereby reducing the formation of oxygen vacancies in the ceramic. The optimal performance was achieved in the Ca0.97Bi2.03Nb2O9-0.3wt.%MnO2 sample, exhibiting a piezoelectric coefficient (d33) of 13.6 pC/N, a DC resistivity of 3x106 Omegacm at 500 degrees C, and a Curie temperature of 965 degrees C. Additionally, all doped samples demonstrated excellent thermal stability over a wide from room to 900 degrees C.

In order to meet the growing demand for small, lightweight, and low-cost electronic and electrical systems, it is urgent to fabricate dielectric materials with high energy density. Poly(vinylidene fluoride) (PVDF) and its copolymers have become the most important dielectric materials in the last two decades. However, the high dielectric loss and low breakdown strength of PVDF limited the improvement of discharged energy density. In this work, in order to achieve high energy density and efficiency simultaneously, it-conjugated 2-(3,6,7,10,11penta (butoxy) triphenyl-2-yl) oxy) ethyl methacrylate (MBT) monomer was copolymerized with methyl methacrylate (MMA) at different feed ratios to obtain the copolymers filler (P(MMA-co-PMBT)). Subsequently, a series of blend films were prepared via solution casting to investigate the effects of the kinds of polymer fillers on dielectric and energy storage properties of PVDF. As a result, the discharge energy density of PVDF/P(MMA19.06- co-MBT 0.94 ) reaches 21 J cm- 3 at 734 MV m- 1 , which is attributed to that the MMA units can restrict the ferroelectric loss and the MBT units can creates traps to depresses charge transfer under an elevated electric field. This work offers a novel organic filler to realize commercial application of PVDF in the field of film capacitors.

High‐temperature dielectric polymers are increasingly attracting significant interest for energy storage applications in harsh environments. However, the exponentially increased conduction losses under high temperatures and elevated electric fields often cause serious degradation of the capacitive performance of dielectrics. Unlike most reported energy‐level tuning strategies, this study introduces a novel approach that constructs localized electrostatic barriers to enhance the high‐temperature energy storage of polyetherimide (PEI) films. By copolymerizing amide groups MPD (1,3‐Phenylenediamine) and PAB (4,4′‐Diaminobenzanilide) into the PEI backbone, the strong electrostatic separation effect of amide dipoles is established, leading to a significant electric potentials difference. Density Functional Theory (DFT) proves that intermolecular local potential fluctuations generate significant hybrid electrostatic barriers (4.2 eV) to trap carriers and suppress their migration within the spatial freedom domain. Consequently, the largely suppressed leakage current and enhanced breakdown strength are yielded in co‐10PAB/90MPD polymer, creating a high energy density of 4.3 J cm −3 ( η > 90%) at 200 °C as comparison to the original PEI‐MPD (2.1 J cm −3 ), which surpasses most high‐temperature energy storage polymers. This work demonstrates a promising paradigm of dipolar regulation at the molecular level for high‐temperature dielectrics.

Nowadays, with the development of hybrid electric vehicles, aerospace, underground oil and gas exploration, and other fields, the demand for high-temperature dielectric energy storage equipment has rapidly increased. Although engineering aromatic polymers with high glass transition temperatures (Tg) have been developed, it is extremely urgent to solve the problem of the sharp decline in energy storage performance caused by the exponentially increased leakage current under high temperatures and electric fields. This work incorporates a semiconductor molecule with donor-acceptor-donor configuration (DPP-S) into the PEI matrix to achieve significantly enhanced high-temperature capacitive performance. The dense physical cross-linking networks are formed by the electrostatic interaction between the positively charged phenyl group in PEI and the electron-donating thiophene group in DPP-S, as well as the hydrogen bonding interaction between the amide group in DPP-S and the-C=O group in the PEI chain. This molecular interface effect improves mechanical strength to boost the breakdown strength and introduces trap sites capturing charge carriers to suppress leakage current. Consequently, excellent energy storage performance is achieved in PEI-DPP-S-0.2 wt%, e.g., discharge energy density of 4.87 J cm-3 at 150 degrees C and 3.45 J cm-3 at 200 degrees C with high discharge efficiency of 90 %, surpassing lots of high-temperature energy storage polymers. Finally, PEI-DPP-S-0.2 wt% exhibits stable performances during ultralong 105 charge-discharge cycles in harsh environments (200 MV m-1 and 200 degrees C) and prospects for largescale preparation. This work further deepens the insight of high-temperature dielectric energy storage enhanced by molecular interface engineering.

Dielectric capacitors offer immense application potential in advanced electrical and electronic systems with their unique ultrahigh power density. Polymer-based dielectric composites with high energy density are urgently needed to meet the ever-growing demand for the integration and miniaturization of electronic devices. However, the universal contradictory relationship between permittivity and breakdown strength in traditional ceramic/polymer nanocomposite still poses a huge challenge for a breakthrough in energy density. In this work, all-organic carbon quantum dot CDs were synthesized and introduced into a poly(vinylidene fluoride) PVDF polymer matrix to achieve significantly boosted energy storage performance. The ultrasmall and surface functionalized CDs facilitate the polar β-phase transition and crystallinity of PVDF polymer and modulate the energy level and traps of the nanocomposite. Surprisingly, a synergistic dielectric enhancement and loss reduction were achieved in CD/PVDF nanocomposite. For one thing, the improvement in εr and high-field Dm originates from the CD-induced polar transition and interface polarization. For another thing, the suppressed dielectric loss and high-field Dr are attributed to the conductive loss depression via the introduction of deep trap levels to capture charges. More importantly, Eb was largely strengthened from 521.9 kV mm-1 to 627.2 kV mm-1 by utilizing the coulomb-blockade effect of CDs to construct energy barriers and impede carrier migration. As a result, compared to the 9.9 J cm-3 for pristine PVDF, the highest discharge energy density of 18.3 J cm-3 was obtained in a 0.5 wt% CD/PVDF nanocomposite, which is competitive with most analogous PVDF-based nanocomposites. This study demonstrates a new paradigm of organic quantum dot-enhanced ferroelectric polymer-based dielectric energy storage performance and will promote its application for electrostatic film capacitors.

Advanced nanofibrous materials with excellent performance and functional integration is highly desired for developing emerging wearable electronics. In this work, carbon quantum dots/poly(vinylidene fluoride) (CDs/PVDF) based composite nanofibrous material is proposed and acts as a highly negative material to boost output performance for triboelectric nanogenerators (TENGs). The nanometer-sized and surface-functionalized CDs acting as nucleating inducers facilitate the polarized beta-phase transition of PVDF polymer. The more negative surface charge density of CDs/PVDF nanofibrous membrane is generated through the polarized beta-phase PVDF, thereby leading to a larger electrostatic potential difference to enhance charge transfer. Besides the decreased beaded defects, more uniform morphology fibers are yielded to improve the effective contact surface area. Moreover, the CDs/PVDF composite nanofibers demonstrate the unique multicolor fluorescence effect enabling promising applications in visualized displays and sensing. Finally, the fabricated TENG features a short-circuit current density of similar to 61.8 mA/m(2) and a maximum peak power density of similar to 11.7 W/m(2), exceeding that of most state-of-the-art nanofiber-based TENG reported to date. As a demonstration of application potential, this TENG shows the energy-harvesting ability to charge capacitors and light up 125 green LEDs and self-powered sensing capability for human motion monitoring. This work provides insights for exploiting novel tribomaterials for high-output TENGs with promising potential in biomechanical energy harvesting, self-powered sensing, and so forth.

Advances in high‐temperature‐resistant polymer dielectric present a crucial opportunity for next‐generation electrostatic energy storage in power electronics. However, the practical application of polymer dielectrics at elevated temperatures (above 150 °C) is largely limited due to the exponential increase in conduction loss under the high thermo‐electric field. In this work, N and S atom‐doped carbon polymer dots (NSCPDs) engineered dual‐barrier to address the critical issue of conduction loss is utilized. Specifically, the doping elements of N and S heteroatoms enhance the NSCPDs' electron affinity and facilitate the formation of deeper traps with energy levels of 1.60 eV compared to pristine CPDs (1.07 eV). Furthermore, the Coulomb blocking effect induced by quantum‐sized NSCPDs can capture electrons and tortuous the electron transport path. Therefore, this constructed “Coulomb blockage‐trap barrier” dual energy barrier effectively suppresses carrier migration and lowers leakage current, enabling the 0.5 wt.% NSCPDs/PEI composite to attain a remarkable energy storage density of 3.49 J cm 3 at 200 °C, which represents a 60% enhancement compared to pristine PEI (2.21 J cm 3 ). The composite simultaneously demonstrates excellent efficiency (η > 90%) and robust cycling stability over 10 5 cycles. This study provides a generalizable materials design paradigm for the development of high‐temperature polymer dielectrics.

With the advancement towards lightweight, integrated, and intelligent capacitors, there is an urgent need to develop flexible dielectric materials with high power density and high energy storage performance. Poly (vinylidene fluoride) (PVDF) based nanocomposite has garnered widespread attention due to its high polarization and ease of processing. However, the inverse relationship between the dielectric constant and breakdown strength constrains its potential for achieving high energy density. Herein, a two-pronged approach effectively combining the incorporation of organic carbon quantum dots (CQDs) nanofiller and PVDF polymer crystallization behavior modulation is utilized to boost the energy density of nanocomposites. Particularly, CQDs increase the crystallinity and decrease the leakage current density of the nanocomposites effectively, resulting in enhanced breakdown strength. Moreover, through optimizing process parameters of stretching temperatures and rate during uniaxial stretching, significantly higher crystallinity, polar phase transition, increased chain orientation, and smoother surface are achieved to construct a denser and more stable microstructure that effectively hinders the formation of electrical breakdown pathways, thereby enhancing the electric polarization and breakdown strength of the nanocomposites. As a consequence, the ultrahigh discharge energy density of 30.8 J/ cm 3 with an efficiency of 74.1 % was yielded at 944.2 kV/mm, representing improvements of 124.8 % and 42.8 %, respectively, compared with pure PVDF (13.7 J/cm3, 51.9 %). These facile uniaxial stretching films present excellent energy storage performance as those obtained by complicated processes, which shows great potential for practical large-scale applications.

Exploring cost-effective and environment-friendly technology for H2O2 production is of great urgency toward net zero carbon emission. Hybridized mechanical and solar energy-driven self-powered H2O2 production is a promising alternative to the traditional anthraquinone oxidation process to address high energy consumption, substantial organic waste generation, and toxic by-products. However, the low conversion efficiency of mechanical energy and the low-activity catalytic material are two main challenges of this method for high reaction efficiency. In this work, we construct a unique hybrid H2O2 production system, which is composed of a rotatory disc-shaped triboelectric nanogenerator (TENG) converting mechanical energy into electrical energy and a catalytic reaction unit integrated with TiO2-BaTiO3-Ag nanowire array (TOBT-Ag) as photoanode. Particularly, an optimal matching design of the transformer in the management circuit boosts TENG's output current from 0.4 mA to 11.3 mA to supply sufficient electricity power for the electrocatalysis module. Moreover, the ultrafine Ag particle loaded on the TiO2-BaTiO3 nanowire array is designed to enhance surface-active catalysis sites and lower the interfacial charge transfer barrier. As a result, the self-powered hybrid catalysis system achieves H2O2 production as high as 29.55 mu mol/L within 5 min. The successful integration of TENG and nanocatalyst in this work demonstrates an efficient route for the H2O2 green production, providing an excellent paradigm for converting renewable natural energy sources into chemical energy.

A comprehensive strategy including charge excitation, interface insulation, and material screening was employed to achieve a record-high output energy density of 4.3 × 10 5 J m −3 for a triboelectric nanogenerator.

High-energy density dielectrics for electrostatic capacitors are in urgent demand for advanced electronics and electrical power systems. Poly(vinylidene fluoride) (PVDF) based nanocomposites have attracted remarkable attention by intrinsic high polarization, flexibility, low density, and outstanding processability. However, it is still challenging to achieve significant improvement in energy density due to the common contradictions between electric polarization and breakdown strength. Here, we proposed a novel facile strategy that simultaneously achieves the construction of in-plane oriented BaTiO3 nanowires and crystallization modulation of PVDF matrix via an in-situ uniaxial stretch process. The polar phase transition and enhanced Young’s modulus facilitate the synergetic improvement of electric polarization and voltage endurance capability for PVDF matrix. Additionally, the aligned distribution of nanowires could reduce the contact probability of nanowire tips, thus alleviating electric field concentration and hindering the conductive path. Finally, a record high energy density of 38.3 J/cm3 and 40.9 J/cm3 are achieved for single layer and optimized sandwich-structured nanocomposite, respectively. This work provides a unique structural design and universal method for dielectric nanocomposites with ultrahigh energy density, which presents a promising prospect of practical application for modern energy storage systems.