Discharge Cycles Research Articles

Intercalation of Polyacrylonitrile Nanoparticles in Ti3C2Tx MXene Layers for Improved Supercapacitance.

We report the intercalation of polyacrylonitrile nanoparticles in Ti3C2Tx MXene layers through simple sonication. The use of polyacrylonitrile, which was synthesized via radical polymerization, offered dual benefits: (1) It increased the interlayer spacing of MXene, thereby exposing more surface area and enhancing ion transport channels during charge and discharge cycles, and (2) Integrating MXene with polyacrylonitrile enables the creation of a composite with conductive properties, following percolation principle. X-ray diffraction analysis showed an increase in the c-lattice parameter, indicative of the interlayer spacing, from 22.31 Å for the pristine MXene to 37.73 Å for the MXene-polyacrylonitrile composite. The intercalated polyacrylonitrile nanoparticles facilitated the delamination by weakening the interlayer interactions, especially during sonication. Electrochemical assessments revealed significant improvement in the properties of the MXene-polyacrylonitrile composite compared to the pristine MXene. The assembled asymmetric device achieved a good specific capacitance of 32.1 F/g, an energy density of 11.42 W h/kg, and 82.2% capacitance retention after 10,000 cycles, highlighting the practical potential of the MXene-polyacrylonitrile composite.

Remarkably Boosted High‐Temperature Electrostatic Energy Storage of Polyetherimide Film Induced by TiO2@Au@AlOx@Au Core‐shell Nanofibers

AbstractPolymer dielectrics have broad applications in advanced electronics and power systems. However, they suffer from low energy density and poor breakdown performance at high temperatures, limiting their applications in high‐temperature environments. Herein, TiO2@Au@AlOx@Au nanofibers with double coulomb blockade nanolayers are obtained via a physical sputtering strategy to improve the high‐temperature energy storage performance of polyetherimide composites. Experimental studies and finite elemenet phase‐field simulations demonstrate that the double‐layer coulomb blockade effect and micro‐capacitor effect of Au nanoparticles synergistically enhance the breakdown strength and dielectric permittivity of polyetherimide composite at high temperatures. Notably, the composite exhibits ultra‐high discharged energy densities of 11.33 and 9.70 J cm−3 at 150 and 200 °C, respectively, along with high charge–discharge efficiencies of 93.4% and 84%, which far exceed that of the polymer nanocomposites reported so far. Furthermore, the composite exhibits excellent charge–discharge cycling performance (>50000 cycles at 400 MV m−1) and high‐power density (1.16 MW cm−3) at 200 °C, making it an ideal candidate for high‐temperature capacitors. Hopefully, these nanofibers not only serve as excellent nanofillers for high‐temperature energy storage dielectric composites but also holds tremendous potential and inspirational significance for other applications such as electronics, biomedical fields, optics, and catalysis.

Integration of Pre‐Activated Carbon‐Fabric Layers for Ampere‐Hour‐Scale Quasi‐Solid‐State Pouch‐Type Zinc–Air Batteries

AbstractAchieving ampere‐hour‐scale capacities in pouch‐type zinc–air batteries (ZABs) requires optimizing key factors, such as preventing inactive ZnO dendrite formation on zinc anodes and enhancing catalytic activity with efficient gas diffusion in the air cathode. Here, a pioneering flexible, large‐area, ampere‐hour‐scale quasi‐solid‐state ZAB is introduced, addressing these challenges through a novel preactivation strategy combined with a layered assembly approach. This method employs mass‐producible fibrous carbon textiles to form flexible fabrics that separate functions within multi‐stacked layers. Preactivated carbon fabric layers, independently functionalized and easily reassembled, enhance scalability and manufacturability. A bilayer catalytic air electrode, incorporating hydrophilic NiFe hydroxide and hydrophobic FeNC regions, ensures efficient charge and mass transfer, significantly boosting catalytic activity. To prevent dendrite formation on the zinc anode, a zincophilic copper interlayer is implemented. This configuration supports rapid, stable charge–discharge cycles at a high current density of 20 mA cm⁻2. The large‐area stacked bipolar structure pouch cells, exceeding 36 cm2, achieve a discharge capacity of up to 2500 mAh, maintaining high cycle stability through discharge–charge cycles with 200 mAh per cycle. This approach significantly enhances the scalability, manufacturability, and production potential of ultrahigh‐capacity wearable ZABs, making them practical for widespread application in various portable and flexible devices.

Investigation of Bi2MoO6/MXene nanostructured composites for photodegradation and advanced energy storage applications

This study presents nanostructured composite Bi2MoO6/MXene heterostructure by using hydrothermal method for photodegradation of the congo-red dye and also for energy storage devices. X-ray diffractometer (XRD), High Resolution Transmission Electron Microscopy (HRTEM), Field emission scanning electron microscope (FESEM) and X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET) were performed to examine the structural properties along with surface area and porosity of the material. Due to addition of MXene the larger surface area and improved pore size help to quickly break down additional organic pollutants by adsorbing them. The band gap of Bi2MoO6/MXene nanostructured composite reduced to 2.4 eV suggesting transfer of electrons from VB to CB. Bi2MoO6/MXene exhibits a high (92.3%) photocatalytic degradation rate for a duration of 16 min which was verified using UV-visible spectroscopy, also scavenger test was conducted to ascertain the reactive agent along with the degradation pathway was confirmed by LCMS. Elemental content was also established by using inductively coupled plasma mass spectrometry (ICP-MS). For estimating energy storage capacity cyclic voltammetry (CV) was performed. It was observed Bi2MoO6/MXene nanostructured composite electrodes had specific capacitance of 642.91Fg− 1, power density of 1.24 kWkg− 1, and energy density of 22.32 Whkg− 1 at a current density of 5Ag− 1 also it exhibited 64.42% capacity retention having current density 20 Ag− 1 throughout 10,000 Galvanostatic charge discharge (GCD) cycles. High electrical conductivity of Bi2MoO6/MXene electrode was again examined by Electrochemical impedance spectroscopy (EIS). These findings demonstrate the potential of Bi2MoO6/MXene nanostructured composites in both photodegradation and energy storage applications.

Sulfur Heterocyclic Quinone Cathodes for Rechargeable Magnesium Batteries: Discharge Voltage, Cycling Stability, and Reaction Reversibility Improved by Sulfur Substitution

Sulfur Heterocyclic Quinone Cathodes for Rechargeable Magnesium Batteries: Discharge Voltage, Cycling Stability, and Reaction Reversibility Improved by Sulfur Substitution

Functionalization Strategies of Iron Sulfides for High-Performance Supercapacitors

AbstractSupercapacitors have emerged as a promising class of energy storage technologies, renowned for their impressive specific capacities and reliable cycling performance. These attributes are increasingly significant amid the growing environmental challenges stemming from rapid global economic growth and increased fossil fuel consumption. The electrochemical performance of supercapacitors largely depends on the properties of the electrode materials used. Among these, iron-based sulfide (IBS) materials have attracted significant attention for use as anode materials owing to their high specific capacity, eco-friendliness, and cost-effectiveness. Despite these advantages, IBS electrode materials often face challenges such as poor electrical conductivity, compromised chemical stability, and large volume changes during charge–discharge cycles. This review article comprehensively examines recent research efforts aiming at improving the performance of IBS materials, focusing on three main approaches: nanostructure design (including 0D nanoparticles, 1D nanowires, 2D nanosheets, and 3D structures), composite development (including carbonaceous materials, metal compounds, and polymers), and material defect engineering (through doping and vacancy introduction). The article sheds light on novel concepts and methodologies designed to address the inherent limitations of IBS electrode materials in supercapacitors. These conceptual frameworks and strategic interventions are expected to be applied to other nanomaterials, driving advancements in electrochemical energy conversion.

Entropy‐Modulated Short‐Chain Cathode for Low‐Temperature All‐Solid‐State Li−S Batteries

AbstractAll‐solid‐state Li−S batteries (ASSLSBs) due to high theoretical energy density and exceptional safety are highly desirable for electric aircraft. However, as the flight altitude rises, the low‐temperature performance is hampered by inadequate practical capacity. Here, we discover that low‐temperature sulfur utilization is constrained by the multi‐step endothermic conversion reaction. By introducing multi‐chalcogen to modulate the local entropy, a short‐chain molecule cathode is designed to shorten the reduction pathways and enhance low‐temperature discharge capacity. Furthermore, the mismatched lithiation lattice of the short‐chain cathode reduces the decomposition energy barriers, thus enhancing low‐temperature charge/discharge reversibility. The designed short‐chain cathode exhibits high cathode utilization (99.4 %) and cycling stability (400 cycles, 92.2 % retention) at room temperature, as well as delivers excellent discharge capacity (579.6 mAh g−1, −40 °C) and cycling performance (100 cycles, 98.4 % retention, 394.9 Wh kg−1electrode, −20 °C) at low temperature. This study presents new opportunities to stimulate the development of low‐temperature ASSLSBs.

Long‐Term Estimation of SoH Using Cascaded LSTM‐RNN for Lithium Batteries Subjected to Aging and Accelerated Degradation

ABSTRACTAccurate estimation of state of health (SoH) of the battery over long‐term is a critical challenge for the battery management systems in electric vehicles. This is due to the challenges in accurately modeling the accelerated aging and degradation phenomena caused by diverse operating conditions of the battery. This paper presents a cascaded recurrent neural networks (RNN) with long short‐term memory (LSTM) to estimate the internal resistance and SoH, taking account of various abnormal operating conditions of the battery. A datasheet‐based degradation model of the battery is developed using fade equations. The training and validation data set for LSTM‐RNN are generated by subjecting the battery model to various factors that cause accelerated degradation, such as fast charging, varying operating temperatures, overutilization, and cell imbalance. The cascaded LSTM‐RNN is trained to estimate SoH only once after the completion of every charge–discharge cycle. The training error index parameters of the proposed SoH estimator are well within 1%, demonstrating the reliability and robustness of the estimator to diverse operating conditions of the battery.

High-Entropy Prussian Blue Analogue Derived Heterostructure Nanoparticles as Bifunctional Oxygen Conversion Electrocatalysts for the Rechargeable Zinc-Air Battery.

In response to energy challenges, rechargeable zinc-air batteries (RZABs) serve as an ideal platform for energy storage with a high energy density and safety. Nevertheless, addressing the sluggish oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in RZAB requires highly active and robust electrocatalysts. High-entropy Prussian blue analogues (HEPBAs), formed by mixing diverse metals within a single lattice, exhibit enhanced stability due to their increased mixing entropy, which lowers the Gibbs free energy. HEPBAs innately enable sacrificial templating, an effective way to synthesize complex structures. Impressively, in this study, we successfully transform HEPBAs into exquisite multiphase (multimetallic alloy, metal carbide, and metal oxide) heterostructure nanoparticles through a controlled synthesis process. The elusive multiphase heterostructure nanoparticles manifested two active sites for selective ORR and OER. By integrating CNT into HEPBA-derived nanoparticles (HEPBA/CNT-800), the HEPBA/CNT-800 demonstrates superior activity toward both ORR (E1/2 = 0.77 V) in a 0.1 M KOH solution and the OER (η = 330 mV at 50 mA cm-2) in a 1 M KOH solution. The RZAB with a HEPBA/CNT-based air electrode demonstrated an open-circuit voltage of 1.39 V and provided a significant energy density of 71 mW cm-2. Moreover, the charge and discharge cycles lasting up to 40 h at a current density of 5 mA cm-2 demonstrate its excellent stability. This work provides an alternative avenue for the rational design of HEPBA's derivative for a sustainable rechargeable metal-air battery platform.

High‐Performance Alkaline Battery‐Supercapacitor Hybrid Based on Bimetallic Phosphide/Phosphate

AbstractTransition metal‐based materials explored for energy storage applications viz. batteries, supercapacitors and more recently battery‐supercapacitor hybrids (BSHs) abundantly involve Co‐based materials. However, the supply chain issues and low electronic conductivity force us to look for alternative options. In this regard, Co‐free binary metal phosphide/phosphate consisting of Ni and V metal (NiVP/Pi) microspheres as the positive electrode of BSH which shows a high specific capacity of 502 C g−1 (1004 F g−1) at 2 mV s−1 while retaining a high specific capacity of 214 C g−1 (428 F g−1) at 12 A g−1 is reported. The high electronic conductivity of binary metal phosphide in NiVP/Pi electrode and the rich electrochemical active sites due to Ni and V metal centres results in exciting performance. More interestingly, the hybrid device is successfully developed by employing NiVP/Pi as the positive electrode and carbon nanotubes (CNTs) as the negative electrode. The hybrid device (NiVP/Pi//CNT) is able to achieve a maximum energy density of 22.17 Wh kg−1 and a power density of 5 kW kg−1 with 91.7% capacitance retention after 7500 continuous galvanostatic charge–discharge cycles.

Recent Advancements and Future Prospects in Lithium‐Ion Battery Thermal Management Techniques

ABSTRACTLithium‐ion batteries (LiBs) are the leading choice for powering electric vehicles due to their advantageous characteristics, including low self‐discharge rates and high energy and power density. However, the degradation in the performance and sustainability of lithium‐ion battery packs over the long term in electric vehicles is affected due to the elevated temperatures induced by charge and discharge cycles. Moreover, the thermal runaway (TR) issues due to the heat generated during the electrochemical reactions are the most significant safety concern for LiBs, as inadequate heat dissipation can be potentially hazardous, leading to explosions and fires. Considering the safety of EVs and for better performance, understanding the mechanism of TR is of paramount importance. This review provides a comprehensive analysis of the TR phenomenon and underlying electrochemical principles governing heat accumulation during charge and discharge cycles. Furthermore, the article explores the cell modeling and thermal management techniques intended for both individual lithium‐ion battery cells and larger battery packs, with a particular emphasis on enhancing fire prevention and safety measures. The main goal of this review paper is to offer new insights to the developing battery community, assisting in the development of efficient battery thermal management systems (BTMS) using enhanced cooling methodologies. This article could also support the advancement of next‐generation electric vehicle battery packs equipped with built‐in safety features to improve the cycle life of LiBs and prevent thermal runaway accidents.

Polymerization of redox-active alizarin in biomass porous carbon with enhanced cycling stability for supercapacitor

Redox-active organic molecules have optimistic application prospects in energy storage due to their high theoretical capacitance, designable electrochemical activity and environmental friendliness. However, low conductivity and solubility in electrolyte severely hinder their redox activity. Here, alizarin molecules containing carbonyl and phenolic hydroxyl are encapsulated in biomass-derived porous carbon, and stable alizarin polymers are further grown on porous carbon substrate by electrochemical polymerization. Porous carbon as conductive network can improve electron transport properties, and provide suitable accommodation environment for confinement and polymerization of alizarin. The electrochemical polymerization strategy on carbon substrate allows alizarin to be connected by rigid C-O-C bond, which inhibits the dissolution of organic monomers while maintaining redox activity. The optimized polyalizarin/porous carbon composite (PAZ/PC-0.5) exhibits superior charge storage performance, with a specific capacitance of 355.8 F g−1 at 1 A g−1 and 220.8 F g−1 at high current density of 30 A g−1. Moreover, PAZ/PC electrode has more durable long-term charge-discharge stability (capacitance retention is 98 % after 10,000 charge and discharge cycles). The assembled symmetrical supercapacitor exhibits excellent energy-power characteristics (21.4 Wh kg−1 at 700 W kg−1) and durable cycle stability. This work sheds light on the design of stable organic electrode towards high-performance supercapacitor.

Experimental assessment of using phase change materials in vapor compression refrigeration systems for condenser pre-cooling

The primary objective of this investigation is to empirically assess a new vapor compression cycle while employing phase change material (PCM) energy storage. During off-peak periods, the PCM undergoes charging, and during on-peak hours, it is discharged to cool the refrigerant entering the condenser, thereby enhancing the condenser's overall performance. In contrast to previous studies that exclusively examined the charging or discharging processes of air conditioning (AC) units, this research delves into the entire 24-h charge and discharge cycle. The proposed system is subjected to testing under identical conditions, both without PCM (conventional mode) and with a PCM storage tank, throughout a 24-h period. The PCM storage tank, which utilizes water as its phase change medium, possesses a volume of approximately 300 L and starts at an initial temperature of 25 °C. The outcomes of the study demonstrate notable improvements when incorporating the PCM storage tank. Specifically, the daily coefficient of performance (COP) increases by approximately 7 %, rising from 2.17 to 2.33. Additionally, it leads to a reduction in both the daily available cooling load and daily compressor energy consumption, with decreases of approximately 3.7 % (from 58.4 to 56.2 kWh) and 10.3 % (from 26.9 to 24.1 kWh), respectively.

Activated biomass-derived 3-dimensional porous graphene-like carbon for high-performance energy storage electrode materials

This article reports studies on the fabrication of active material for supercapacitor electrodes, from 3D porous graphene-like carbon (GLC), synthesized by carbonization from coffee waste (CW) and tea waste (TW) at 550 °C, followed by thermochemical activation in KOH at 850 °C in a quartz tubular furnace. The microstructure of coffee and tea waste shows the form of micro- and mesopores during carbonization and further chemical activation forms hierarchically highly porous 3D graphene-like carbon. GLC-CW exhibited a higher specific surface area (SSA) of 3486 m2/g according to the Brunauer-Emmett-Teller (BET) method, compared to GLC-TW, which had an SSA of 2407 m2/g. These results highlight the effectiveness of graphene-like carbon derived from coffee and tea waste, demonstrating its potential as a promising material for high-capacity supercapacitors. The electrochemical characteristics of the assembled supercapacitors using GLC-CW and GLC-TW revealed significantly higher specific capacitance values of 214 F/g and 182 F/g respectively, along with cycling stability of 98 % and 95 % during 5000 cycles of charge and discharge at 2 A/g current density. This approach can produce high-performance electrode materials for supercapacitors at a reasonable cost and with easy scalability.

Electrochemical oxidation-driven formation of nickel/nickel-based compounds on hollow carbon shells: Mechanistic insights and energy storage applications

Hydrangea-like nickel/nickel-based compounds decorated hollow carbon shells were synthesized through low-temperature calcination and a facile electrochemical oxidation process. This three-dimensional hollow hierarchical structure ensures intimate contact between the electrically conductive nickel (Ni) substrate and uniformly distributed electrochemically active nickel-based compounds. This hierarchical structure offers abundant active sites and accessible pathways, maximizing energy storage, particularly during rapid charge–discharge cycles. With 30 min of electrochemical oxidation, the optimized Ni-compound-based electrode exhibits a specific capacity of 643 C g−1 at 1 A/g. When assembled into a nickel-zinc battery cell with a zinc foil anode, the cell demonstrates swift current responses, with full capacity recovery even after a twentyfold increase in current density, followed by a return to 1 A/g. Density functional theory computations reveal that the electrochemical oxidation, conducted for an optimized duration, results in partial oxidation of Ni(OH)2, reducing the surface adsorption energy of OH− from the electrolyte and improving charge storage capacity.

Pre-magnetization smashing hydrated vanadium ions to improve redox flow batteries performance

The vanadium redox flow battery (VRFB) has received extensive attention due to its intrinsic safety and high scalability. Currently, there are still deficiencies of low energy efficiency and higher unit capacity cost in VRFB energy storage. Continuously optimizing the battery performance through reducing electrode polarization losses is a necessary way to achieve efficient VRFB energy storage technology. In this study, a method of pre-magnetizing the electrolyte to improve the performance of the battery was proposed. A permanent magnet with an intensity of 0.9 T was used to pre-magnetize the vanadium-ion aqueous electrolyte before feed into the battery stack and working-on, it was found that the diffusion capacity of vanadium ions increased by 133.6 % after pre-magnetized even if the external magnetic field was removed. Meanwhile, both of the charge transfer and concentration polarization resistance of the electrode were reduced. The energy efficiency (EE) of the battery was increased by 6.4 % in the charge–discharge test at current density of 300 mA cm−2. The power density increased by 6.19 % with current density 400 mA cm−2 at most, and it prefers to continuously increase as current larger. The electrolyte pre-magnetization showed significant positive improvements on the electrode reaction kinetics and battery charge–discharge cycle.

Dual storage mechanism of Bi2O3/Co3O4/MWCNT composite as an anode for lithium-ion battery and lithium-ion capacitor

Bismuth oxide(Bi2O3) and cobalt oxide(Co3O4) are promising owing to their unique properties, high storage capacity, low cost, and eco-friendliness, making them ideal for lithium-ion batteries(LIBs) and lithium-ion capacitors(LICs) anodes. This study presents the synthesis and thorough characterization of Bi2O3/Co3O4 and Bi2O3/Co3O4/MWCNT composites as potential LIB and LIC anode materials. The materials are synthesized using a hydrothermal process succeeded by annealing. Structural, morphological, and compositional studies were analyzed. Various tests evaluated electrochemical performance, including cyclic voltammetry(CV), confirming a dual storage mechanism like alloying and conversion reaction involved for better energy storage. Specific discharge capacities of 834 mAh/g and 1184 mAh/g were recorded for Bi2O3/Co3O4 and Bi2O3/Co3O4/MWCNT composite electrodes at a current density of 100 mA/g, respectively. The composite material exhibited notably enhanced rate capability, with 31 % and 51 % discharge capacities for Bi2O3/Co3O4 and Bi2O3/Co3O4/MWCNT, respectively. The cyclic stability assessment revealed that Bi2O3/Co3O4 and Bi2O3/Co3O4/MWCNT maintained a high coulombic efficiency of around 99 % over 250 charge–discharge cycles at a high current density of 1 A/g. The capacity retention was approximately 253 mAh/g for Bi2O3/Co3O4 and 439 mAh/g for the Bi2O3/Co3O4/MWCNT composite, indicating excellent cyclic stability and minimal energy loss during cycling. Moreover, the LICs assembly of Bi2O3/Co3O4/MWCNT//CB was investigated, revealing a power density of 200 W kg−1 alongside an energy density of 8.64 Wh kg−1. The cyclic stability assessment over 10,000 cycles exhibits a capacity retention of approximately 45 % under a high current density of 2 A/g.

An insight into synergistic effect of polyaniline and noble metal (Ag) on vanadium pentoxide nanorods for enhanced energe storage performance

The widespread applications of vanadium pentoxide (V2O5) are limited because of its low electrical conductivity and restricted ion diffusion coefficient. To address these constraints, the present study includes a straightforward and effective approach for fabricating polyaniline based silver-decorated vanadium pentoxide (Ag-V2O5/PANi) as an electrode material. The structural and morphological investigation of prepared electrode materials were made by X-ray diffraction analysis and scanning electron microscopy respectively. In comparison to pure Ag-V2O5, the Ag-V2O5/PANi composite demonstrated enhanced performance in various aspects. Specifically, the Ag-V2O5/PANi showed a higher specific capacitance (628 Fg−1) when subjected to a current density (1 Ag−1) in KOH electrolyte. Additionally, it has an energy density of 153 Whkg−1. Furthermore, the Ag-V2O5/PANi composite exhibited superior stability even after undergoing 3000 charge to discharge cycles. Exceptional capabilities shown can be ascribed to synergistic interaction between PANi and Ag-V2O5. The remarkable outcomes obtained from these electrode materials have the potential to foster novel prospects in high-energy-density storage systems.

Stacked borophene-based electric double-layer supercapacitors

As an exceptional metallic Dirac material, borophene shows promise for superior mechanical and electronic properties, making it increasingly significant in electronics. Both theoretical predictions and experimental evidence underscore its potential in energy storage applications. However, due to existing limitations in synthesis techniques, the application of stacked borophene as flexible electrodes remains unexplored. This study aims to overcome these challenges by introducing an innovative in situ co-eutectic salt method for synthesizing AB-stacked hydrogenated borophene sheets. These sheets are then employed to fabricate large-scale electrodes and construct flexible electric double-layer supercapacitors based on borophene. The robust mechanical stability of stacked borophene facilitates significant improvements in interfacial characteristics and energy storage performance through rolling processes. This enhancement results in increased specific capacity, improved rate performance, and enhanced cyclic stability of thin-film electrodes. Specifically, the optimized borophene-based supercapacitor achieves a high specific areal capacitance of up to 417.3 mF/cm2 in an organic electrolyte at a current density of 1 mA/cm2, which represents a twofold improvement compared to non-stacked borophene structures. Remarkably, it retains over 88.3 % of this specific areal capacitance even at a high current density of 15 mA/cm2, demonstrating impressive rate capability. Furthermore, after 5000 charge–discharge cycles, the capacitance retention exceeds 89.3 %. This research is expected to catalyse the application and advancement of borophene in future flexible and portable electronic devices, highlighting its potential transformative impact in energy storage technologies.

Enhanced high-temperature energy storage performance in all-organic dielectric films through synergistic crosslinking of chemical and physical interaction

Advanced electronic devices and energy systems urgently require high-temperature polymer dielectrics that can offer both high discharge energy density and energy storage efficiency. However, the capacitive properties of most polymers sharply deteriorate at elevated temperatures, due to the significant rise in leakage current density and energy loss. Herein, a new design approach is adopted to fabricate high-temperature polyetherimide (PEI) dielectrics with chemical and physical cooperative crosslinking networks, the dual-crosslinked PEI dielectrics are prepared through amine crosslinking agent and the electrostatic interaction of oppositely charged phenyl groups between triptycene (TE) and PEI chain segments. Benefiting from the increased crosslinking sites, the dual-crosslinked PEI films achieve the simultaneously enhancement in Tg, modulus and bandgap compared to un-crosslinked and single-crosslinked polymers. Meanwhile, the PEI with dual-crosslinked network displays higher chain packing density, effectively reducing the mean motion pathways of charge carriers and the conduction loss inside polymer dielectric. Consequently, the dual-crosslinked PEI containing 0.25 wt% TE delivers an outstanding discharge energy density of 2.69 J/cm3 and retains excellent cyclability after 100,000 charge–discharge cycles at 200 ℃. Additionally, finite element analysis and molecular dynamics simulation further confirm that less Joule heat and tighter chain structure are formed in the dual-crosslinked polymer dielectric. This research offers a novel methodology to prepare high-performance polymer dielectrics for high-temperature applications.