JOURNAL OF POWER SOURCES
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2024
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IF 8.1
Hongmei Qin,Ziwei Li,Shiyu Qin,Yanda Jiang,Man Liu,Ling Zhou,Siyu Yu,Shan Wang,Chuanxi Xiong
High-temperature polymer dielectric capacitors are urgently needed in the new-generation electronic and electrical systems. Whereas, current commercial polymer represented by polyimide (PI) suffer from exponentially growing conduction loss at high temperatures and high electric fields, and hence extremely low discharged energy density and sharply declined charge-discharge efficiency. In this work, we developed superior Al 2 O 3 /PI/Al 2 O 3 sandwich films with drastically improved capacitive energy storage performance via atomic layer deposition (ALD) technology. Notably, resultant PI hybrid dielectrics deposited by 130 nm-thickness Al 2 O 3 (Al 2 O 3 /PI/Al 2 O 3 -130nm) exhibits the highest breakdown strength and the lowest leakage current density compared to pristine PI. Consequently, Al 2 O 3 /PI/Al 2 O 3 -130nm delivers a discharged energy density of 4.9 J/cm 3 at 25 °C and 3.3 J/cm 3 at 150 °C, as high as 2.7 times and 3.3 times respectively that of near PI film. Moreover, PI hybrid dielectrics can operate steadily under 200 MV/m and 150 °C during 10,000 cycle measurements. The excellent performance is mainly attributed to the improved barrier height of the electrode/PI interface endowed by deposited large-bandgap Al 2 O 3 .This work provides a scalable approach to enable excellent high-temperature energy storage performance of polymer dielectrics and promising to promote the application of PI for capacitive energy storage under harsh conditions.
研究领域:
材料科学
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电气工程
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CHEMICAL ENGINEERING JOURNAL
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2024
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IF 13.3
Feng Wang,Hao Wang,Xiaoming Shi,Chunli Diao,Chaolong Li,Weikun Li,Xu Liu,Haiwu Zheng,Houbing Huang,Xiaoguang Li
High-temperature polymer-based dielectric capacitors are crucial for application in electronic power systems. However, the storage performance of conventional dielectrics polymer dramatically deteriorates due to the thermal breakdown under concurrent high temperatures and electric fields, and there are hardly reports on the causes of thermal breakdown from the aspects of the high-temperature conduction loss and Joule heat dissipation. Herein, a combined strategy of crosslinking and compositing for polyimide-based composites is proposed, which minimizes the thermal breakdown by significantly inhibiting the high-temperature conduction loss and enhancing the thermal conductivity. Furthermore, the rationale of the strategy was theoretically and experimentally verified from multiple perspectives. The charge-trapping effect is directly observed by Kelvin probe force microscopy probed (KPFM) with nano-level resolution and quantitatively by thermally stimulated depolarization current measurements, indicating that the crosslinking network introduces local deep traps and effectively suppresses the charge transport. The thermal conductivity of the composites inhibits the high-temperature thermal breakdown, which is confirmed by phase-field simulations. Consequently, the optimized composites possess an ultra-high discharge energy density ( U d ) of 5.45 J/cm 3 and 3.54 J/cm 3 with a charge–discharge efficiency ( η ) of 80 % at 150 and 200 °C, respectively, which outperforms the reported polyimide-based dielectric composites. This work provides a scalable direction for high-temperature polymer-based capacitors with excellent performance.
研究领域:
材料科学
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电子工程
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能源存储
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JOURNAL OF ELECTRONIC MATERIALS
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2024
·Vol. 53
·期 6
·3320-3328
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IF 2.2
Liang Yuzhou,Li Ting,Wang Xue,Yang Chao
Nitrogen-doped carbon is a major class of high-performance electrode materials for the electrochemical supercapacitor. Herein, nitrogen-doped carbon was obtained by pyrolysis to graphene-grafted polyimide precursors on carbon cloth through in situ polymerization. The morphology, structure, and electrochemical properties of flexible electrodes were investigated in detail. Scanning electron microscopy (SEM) confirmed the preparation of nitrogen-doped carbon on carbon cloth. X-ray photoelectron spectroscopy (XPS) characterization showed the doping of the N heteroatom. Flexible electrodes obtained with the optimized mass graphene delivered high specific capacitance of 669 F g −1 at 0.5 A g −1 and good cycle stability, with retention of 122.3% capacitance after 6000 cycles in a three-electrode system. These typical flexible electrodes show great potential in wearable energy storage devices.
研究领域:
材料科学
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电化学
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JOURNAL OF MEMBRANE SCIENCE
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2025
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IF 9
Ji Ma,Wen He,Weiwang Lim,Jingcheng Du,Qian Sun,Shabi Ul Hassan,Dong Cao,Jian Guan,Jiangtao Liu
Polyimide membranes offer the potential of industrial natural gas sweetening to effectively diminish carbon dioxide from raw streams, but it remains a challenge to improve the separation selectivity and further overcome the trade-off limitation through synthesis design. Here, we present an A 2 +B 2 +B 3 strategy to fabricate a series of polyimides containing hyperbranched network structures by copolymerizing the triamine monomer (TAPA) in conjunction with linear 6FDA-6FAP. The chemical structures and physicochemical properties of polyimides were confirmed by SEM, FTIR, XPS, TGA and XRD. The molar ratio changes of 6FAP/TAPA finely tailored the fractional free volume from 16.9 % to 13.1 % and brought about high packing efficiency, leading to a surge in separation selectivity. The 6FDA-6FAP/TAPA (7:3) membrane exhibited a maximum CO 2 /CH 4 selectivity of 134.5 with a permeability of 26.9 Barrer, improving the CO 2 /CH 4 separation performance of 6FDA-6FAP from far below the 1991 limitation to beyond the 2008 Robeson's upper bound line. Diffusivity and solubility acting as the main factors that govern the gas separation were also carefully investigated. Additionally, 6FDA-6FAP/TAPA(7:3) demonstrated high CO 2 /CH 4 binary gas separation performance, good high-temperature (105 °C) reversibility, great plasticization resistance (20 bar) and moderate long-term stability (360 days) under practical working conditions. These results indicate that hyperbranching of polyimide can be successfully controlled to enhance the separation properties, which facilitate the development of high-performance gas separation membranes with topological microstructures.
研究领域:
材料科学
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化学工程
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ACS Applied Polymer Materials
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2024
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IF 4.4
Huijian Ye,Lianlian Chen,Huilei Jiang,Lixin Xu
Dielectric film capacitors have received extensive attention because of their fast release rate and great electrical reliability. A polymer film with large energy density and charge–discharge efficiency is required to expand the application of film capacitors at high temperatures. In this work, a series of ternary fluorinated polyimides (FPI) with different fluorine-containing ratios have been copolymerized to investigate the high-temperature electrical displacements. The fluoro-dianhydride monomer was introduced into the regular 4,4′-diaminodiphenyl ether polymerization system with accompanied thermal imidization. The FPI film exhibits large energy capability with intrinsic breakdown strength compared with pristine PI, which is ascribed to the strong electronegative effect and hydrophobic feature of –CF3 as well as the increase of free volume in bulk. The energy density of optimal FPI film reaches 20.2 J/cm3 at 659 MV/m, and the high-temperature energy storage property is improved, e.g., the energy density up to 11.5 J/cm3 with an external field of 525 MV/m at 100 °C. Low molar polarizability between C–F bonds also contributes to the decreased leakage current, which results in the large charge–discharge efficiency under high temperatures. The PI film with tailored fluorostructure demonstrates the competing candidate for the application of a high-temperature polymer film capacitor.
研究领域:
材料科学
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电气工程
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JOURNAL OF APPLIED POLYMER SCIENCE
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2024
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IF 2.7
Bo Mu,Yun'an Li,Kang Du,Xiaoqin Dai,Li Tian,Junhong Guo,Baoping Yang,Jinfeng Cui,Xuemei Bao
Dimensionally stable and high strength Polyimide(PI)/nKevlar composite aerogels are fabricated by the inclusion of nano Kevlar fibers with PI precursor polyamide acid via solution mixing and subsequent vacuum drying. The rigid macromolecular structure of nKevlars and the intermolecular hydrogen bonding result in lower shrinkage/density and larger porosity. The PI/nKevlar composite aerogels demonstrate a 23.4% reduction in the linear shrinkage. Compared with pure polyimide aerogel, the friction coefficient and wear rate of composite aerogel decreased significantly, with the dry friction wear rate of the PI/nKevlar-1.0 reduced by 34.14% and the friction coefficient of the oil-containing aerogel reduced by 28.29% ascribing to the increased loading bearing of the composite.
研究领域:
材料科学
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摩擦学
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POLYMER COMPOSITES
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2026
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IF 4.9
Xiaoyi Wei,Han Lu,Lixiu Zhang,Zhongliang Yang,Zhenyu Yin,Ting Li
Polyimide (PI) is widely used in high-end engineering sectors, including aerospace and defense, due to its exceptional mechanical properties. However, pristine PI exhibits critical limitations during service, including a high coefficient of friction, severe wear, and mechanically induced microcrack formation. In this study, melamine-urea-formaldehyde (MUF) was used as the shell material and E-51 (Ep) as the core material to synthesize MUF@Ep microcapsules via an in situ polymerization method. The microcapsules were then incorporated into a PI matrix to fabricate multifunctional composites exhibiting both self-healing and self-lubricating properties. The tribological properties were systematically evaluated as functions of microcapsule content and applied load using a ball-on-disk reciprocating tester. The results showed that the composite containing 4.5 wt% microcapsules exhibited optimal performance at 30 N, with the coefficient of friction and volumetric wear rate reduced by 24.44% and 45.68%, respectively, compared with pristine PI. After heating at 150°C for 60 min, self-healing of the damaged area was achieved. During multi-cycle in situ friction-healing tests, the samples exhibited excellent tribological performance and wear healing under friction conditions, achieving a maximum healing efficiency of 41.42%. Therefore, the MUF@Ep/PI-based composites demonstrated superior tribological performance and reliable self-healing capability. This study provides a viable strategy for high-end engineering applications and for the design of adaptive intelligent materials suitable for complex service environments. Highlights Developed composites with self-healing and self-lubricating functions. Epoxy resin serves as both a lubricant and a healing agent. Self-healing achieved without additional curing agents. Realize the self-healing of friction-induced abrasion marks.
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CHINESE JOURNAL OF POLYMER SCIENCE
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2026
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IF 4.6
Zhang Qiao-Ran,Wang Xin-Fei,Chen Ya-Nan,Zhou Bo-Yuan,Wei Hong-Liang,Cao Xiao-Yu,Wang Jin
Passive thermal regulation materials offer a promising route toward energy-efficient building and smart devices. However, achieving both passive radiative cooling and solar-driven heating within a single polymeric system remains a significant challenge due to trade-offs in optical transparency, solar reflectivity, and environmental durability. Herein, we report a molecularly engineered polyimide (PI) film platform with switchable cavitation (realized through controlled cross-linking) that enables bidirectional thermal regulation. By tuning the molecular architecture, the PI films can be fabricated into either a highly porous, white reflective film for passive cooling (about 90% solar reflectivity, Δ T is about −6 °C) or a transparent solid film for passive heating (about 88.7% solar transmittance, Δ T is about +8 °C). The films exhibit excellent flame retardancy (PHRR is about 7.98 W·g −1 ), thermal stability ( T max > 500 °C), and environmental resistance to UV and acidic conditions. Comprehensive outdoor and simulated tests confirm their dual-mode thermal regulation capabilities. This work presents a versatile strategy for designing robust, multifunctional PI materials for year-round thermal management in extreme environments, paving the way for next-generation energy-saving polymers.
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ELECTROCHIMICA ACTA
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2026
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IF 5.8
Yan Bao,Shijia Chen,Yitian Su,Chao Liu,Cang Yang
Triazine-based polyimide anode (PI NA ) synthesized from melamine and NTCDA. • Reversible capacity maintained over 0.1-3.2 A·g -1 in Al 2 (SO 4 ) 3 electrolyte. • Fast surface-controlled charge storage contributes up to 78% of total capacity. • Ion diffusion coefficients reach 10 -9 -10 -10 cm 2 ·s -1 , supporting rapid kinetics. • 4-hydroxy-TEMPO//PI NA full cell shows stable cycling and practical fast-charging operation. Aqueous batteries are attractive for safe and cost-effective energy storage owing to their intrinsic nonflammability and high ionic conductivity. However, their high-rate performance is often restricted by sluggish electrode kinetics and interfacial polarization. Herein, a triazine-containing polyimide negative electrode, denoted as PI NA , was synthesized from melamine and 1,4,5,8-naphthalenetetracarboxylic dianhydride, and its electrochemical behavior was evaluated in a series of aqueous electrolytes. Among the electrolytes examined, 1 mol·L -1 Al 2 (SO 4 ) 3 provided the most balanced electrochemical response, combining reversible capacity, Coulombic efficiency, and cycling stability. At a current density of 3.2 A·g -1 , PI NA exhibited a capacity retention of 75.7%. Kinetic analyses revealed a substantial surface-controlled capacitive contribution and apparent chemical diffusion coefficients on the order of 10 -10 -10 -9 cm 2 ·s -1 , consistent with its rapid charge-storage response under the tested conditions. A 4-hydroxy-TEMPO//PI NA aqueous full cell was further assembled as a proof of concept. The cell operated between 0 and 1.0 V and exhibited a median discharge voltage of approximately 0.44 V at 500 mA·g -1 , together with reversible rate behavior and cycling performance. A smartwatch demonstration further showed that the charged cell could provide short-term electrical output. These results highlight the importance of matching polyimide redox chemistry with the ionic and solvation environment of aqueous Al-containing electrolytes. Schematic diagram of the preparation process and electrochemical performance evaluation of the PI NA negative electrode. Download: Download high-res image (254KB) Download: Download full-size image
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Applied Materials Today
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2026
·
IF 7
Jiangpeng Li,Wei Fan,Yao Chai,Minghui Qiu,Qi Chen,Wenting Kong,Kunlong Yun,Ruiwen Shu,Hao Jia
Aerogel, with its three-dimensional lightweight and porous structure, is a promising candidate for wave absorption applications. Despite this promise, a formidable challenge remains in developing electromagnetic wave absorption materials that can dynamically adapt to real-time environmental fluctuations. In this research, we have developed an ultra-elastic polyimide nanofiber (PINF) aerogel reinforced with reduced graphene oxide (rGO), creating a robust, continuous, and isotropic fiber network. Our findings reveal that by adjusting the compression shape parameters, the composite material exhibits tunable impedance matching properties, enabling selective wave absorption. Remarkably, the wave absorption intensity of this composite aerogel can be dynamically modulated to exceed −59.7 dB under various compression states, demonstrating dynamically tunable microwave absorption properties. This breakthrough showcases the material’s adjustable intelligent functionality and its potential to serve as a switchable electromagnetic wave absorption solution, offering a novel approach to the development of smart materials with responsive electromagnetic properties.
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2026
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IF 3.9
Zimei Zhang,Min Deng,Xinyu Wang,Lin Yang,Lu Yao,Wenju Jiang,Junfeng Zheng,Zhongde Dai,Wenlai Xu,Xiaochen Gao,Wenhong Li,Jinchao Li,Bo Tang
We report a high-performance carbon molecular sieve (CMS) membrane derived from a novel three-dimensional cross-linked polyimide (CBPI) synthesized from self-made triamine (1,3,5-triple (2-trifluoromethyl-4-aminobenzyl) benzene [TFAPOB]), cyclopentanone bis-spirocyclobutane tetracarboxylic dianhydride (CpODA), and 4,4-(hexafluoroisopropylidene)-diphthalic anhydride (6FDA). The unique cross-linked and fluorinated structure of CBPI endows the precursor with high thermal stability and enables the formation of an ultramicroporous, graphitized carbon framework with a tunable pore structure upon controlled pyrolysis. Optimized carbonization at 550 °C yields a CBPI-550 CMS membrane offering exceptional CO2 (3038.3 Barrer) and H2 (4325.8 Barrer) permeability, with CO2/CH4 and CO2/N2 selectivities reaching the 2019 Robeson upper bounds. At higher temperatures, H2/CH4 and H2/N2 selectivities exceed the 2015 bounds. Structural characterization (e.g., XRD, Raman, etc.) links this performance evolution to increased graphitization, reduced interlayer d-spacing, and narrowed pore-size distribution. Moreover, the membranes demonstrate promising stability and adaptability under varying operational conditions, highlighting their potential for practical CO2 capture and H2 purification.
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CHEMICAL ENGINEERING JOURNAL
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2026
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IF 12.5
Zhiyun Li,Yizihan Yu,Jiayi Wang,Taowen Dong,Qiushi Zhang,Zhenhai Gao,Weidong Liu,Weitao Zheng
Carbon fibers (CFs) play a pivotal role in electrochemical/mechanical integrated technologies because of their concurrent high specific strength and excellent electrical conductivity. However, the inherently low specific surface area of CFs limits their charge storage capacity, hindering their commercialization in structural–electrochemical integrated systems. Therefore, the primary objective of modifying CF-based electrodes is to significantly enhance their electrochemical performance while preserving their intrinsic high mechanical properties. In this work, a laser-induced processing strategy, as an effective surface engineering tool, was used to optimize polyimide/activated carbon-coated CFs. This approach involves a gradient architecture consisting of a porous graphitized surface layer (shell) that transitions to a densely cross-linked subsurface region (core). This core-shell structure simultaneously enhanced the mechanical and electrical properties of the CF electrode. Moreover, we systematically investigated the laser processing parameters to break the trade-off between the dense protective layer and ion transport kinetics in the core and shell. Consequently, the modified CF electrode showed a 1.3-fold increase in tensile modulus and a 22.3-fold increase in specific capacitance, compared to the pristine counterpart.
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