ELECTROCHIMICA ACTA
·
2017
·
IF 4.798
Yuenan Chen,Ziming Li,Nanjun Chen,Rui Li,Yajun Zhang,Ke Li,Fanghui Wang,Hong Zhu
In this paper, we prepared a series of ionic liquids including methyl ionic liquids, ethyl ionic liquids and hydroxyethyl ionic liquids. We used the common polymer backbone polyphenylene ether and the conventional conductive group triethylamine . We introduced three different ionic liquids to investigate different effects of the extent of ion conductivity improvement from its structure change. The introduction of ionic liquid significantly improved the ionic conductivity of the alkaline membrane. The highest conductivity of the composite membranes was 2.5 times higher than that of the pure membrane. A certain amount of nano-TiO 2 was added into the membranes through ultrasound dispersion to form a series of trimethylamine-nano-TiO 2 -ionic liquid composite membranes. We found that TiO 2 -ethyl ionic liquid composite membrane has optimal performance, whose ionic conductivity up to 59.27 mS/cm. and the degradation rate of ionic conductivity is 27.4% under strong alkali conditions. The water uptake and swelling ratio of the composite membrane are relatively low, and the thermal stability and mechanical properties also meet the requirements of the application.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2019
·
IF 7.015
Nanjun Chen,Chuanrui Lu,Yunxi Li,Chuan Long,Ziming Li,Hong Zhu
A practical polyelectrolyte system to improve the ion conductivity and lifetime of anion exchange membranes (AEMs) is a critical requirement for alkaline membrane fuel cells (AMFCs). Crosslinking is an effective approach to optimize the performance of AEMs. However, ordinary crosslinkers with a hydrophobic structure always make AEMs mechanically brittle. Herein, in response to the requirement of high-performance AEMs, a series of tunable multi-cation-crosslinked poly(biphenyl piperidinium) (PBP-xQ4) membranes were designed and prepared by embedding flexible cationic crosslinkers. The number of alkyl spacers between the cationic groups in the flexible crosslinkers were optimized to 5 and 6 to achieve optimum performance. These PBP-xQ4 membranes simultaneously have high ion conductivity (155 mS/cm at 80 °C) and good dimensional stability, and these membranes can be folded into many shapes. Besides, the crosslinking also promotes the alkaline stability of these membranes in 2 M NaOH at 80 °C: only a slight degradation is detected by 1 HNMR after alkaline treatment for1800 h. All these impressive results in ion conductivity and durability are attributed to clear nanophase separation in PBP-xQ4 membranes. Moreover, the PBP-xQ4 membrane realizes a maximum power density of 234 mW/cm 2 at 80 °C.
研究领域:
材料科学
·
燃料电池技术
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产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2024
·
IF 5.5
Jinhui Zhang,Zhenghao Chen,Tsung-Cheng Yang,Jingjing Zhang,Hao Zheng,Chen-Hao Yeh,Zeyi Jiang,Chia-Min Yang,Lei Liu,Nien-Chu Lai
Fuel cells promise high energy density and energy conversion efficiency but are plagued by the scarcity of platinum for facilitating the oxygen reduction reaction (ORR). Herein, a facile synthesis of a heterojunction electrocatalyst of ZIF-8 derived carbon (Z8C) supported Fe 2 P 2 O 7 (Fe 2 P 2 O 7 @Z8C) is reported. The electrocatalyst exhibited higher half-wave potential than the state-of-the-art Pt/C catalyst by more than 33 mV and achieved a peak power density of 152.47 mW cm −2 , outperforming the Pt/C-driven cell by ca. 14.5 mW cm −2 in alkaline membrane electrode assemblies under similar operating conditions. X-ray photoelectron and X-ray absorption spectroscopic studies suggested a spontaneous electron redistribution across the heterojunction interface in Fe 2 P 2 O 7 @Z8C. Density functional theory calculations indicated that the electron redistribution may remarkably promote the intrinsic activity of Fe 2 P 2 O 7 @Z8C toward the four-electron ORR pathway. These findings offer an indispensable strategy for rational design of highly efficient and durable non-noble electrocatalysts.
研究领域:
材料科学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2018
·
IF 6.578
Nanjun Chen,Chuanrui Lu,Yunxi Li,Chuan Long,Hong Zhu
Herein, for realizing the high efficiency and long lifetime of hydroxide exchange membranes (HEMs) for alkaline membrane fuel cell (AMFC) applications, a series of robust poly(biphenyl piperidinium) (PBP)/6-azaspiro[5.5] undecane (ASU)-functionalized polyphenyl ether (ASU-PPO) membranes were prepared by a crosslinked strategy. Crosslinked PBP-ASU-PPO membrane combines the advantage of PBP and ASU-PPO membranes as well as addresses the problem of high water uptake of PBP and the insufficient film-forming property of ASU-PPO. As expected, these crosslinked PBP-ASU-PPO membranes exhibit commendably comprehensive performances, such as good ion conductivity, durability, and mechanical properties . The crosslinked PBP-ASU-PPO membrane reaches a maximum OH − conductivity of 128 mS/cm at 80 °C, accompanying with a 15.7% membrane swelling. Besides, only 13.6% degradation in Cl − conductivity was observed in PBP-ASU-PPO after alkaline treatment in 1 M NaOH at 80 °C for 2000 h. Besides, the selected PBP-ASU-PPO membrane achieves a maximum power density of 324 mW/cm 2 at current density of 750 mA/cm 2 .
研究领域:
材料科学
·
能源科学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2023
·Vol. 11
·期 20
·10738-10747
·
IF 11.9
Xiaofeng Li,Bin Zhang,Jing Guo,Yaohan Chen,Lei Dai,Jifu Zheng,Shenghai Li,Suobo Zhang
The preparation of self-supporting anion exchange membranes with enhanced mechanical strength and ultrathin thickness is still a challenge to improve the performance of fuel cells. In this work, we developed 9-dodecylidene-9H-fluorene (DDF) as a branched monomer to construct branched structures based on poly(arylene piperidinium)s. After introducing a 2.5% molar ratio of DDF, quaternized poly(piperidinium-triphenyl-dodecylidenefluorene) (PPTDF-QA) possesses low water swelling (below 25% at 80 °C) and high mechanical strength (over 70 MPa). The obvious phase-separation behavior of the branched membranes induced by the long alkyl chain improves hydroxide conductivity which reaches 168 mS cm−1 at 80 °C. Meanwhile, the thickness of branched PPTDF-QA can be optimized to 8 μm. The present work reveals that a facile branched monomer can promote the formation of a microphase-separated morphology of the membrane to fabricate high-performance anion exchange membranes.
研究领域:
材料科学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
Small
·
2025
·Vol. 21
·期 36
·2506058
·
IF 12.1
Zhuming Mao,Yansong Zhou,Yina Guo,Yanjing Liu,Yang Liu,Minghui Cui,Qiongrong Ou,Shuyu Zhang
Constructing stable electrodes is the premise of practical water electrolysis. Unfortunately, the catalytic performance under industrial conditions encounters critical challenges in bubble dynamics, wherein the violent bubble accumulation not only blocks active sites against reactants but also induces excessive stress upon detachment, leading to catalyst delamination from substrates. Here, a substrate-strengthened and crack-configured NiCoP electrode is developed, which features robust catalyst-substrate binding strength and weakened adhesion at the catalyst-bubble interface. The precisely engineered dual interfaces enable improved mechanical stability, facilitated bubble desorption, and optimized reaction kinetics for high-rate hydrogen evolution. The catalyst exhibited an ultra-low overpotential of 288 mV at 1000 mA cm −2 , with robust stability over 200 h. Furthermore, when served in an anion exchange membrane water electrolyzer (AEMWE), a minimized cell voltage of 1.76 V is recorded at 1000 mA cm −2 and operated stably for 150 h. This work provides intriguing concepts for designing electrodes toward industrial green hydrogen applications.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nature Nanotechnology
·
2023
·Vol. 18
·期 3
·299-306
·
IF 38.3
Wei Pengfei,Gao Dunfeng,Liu Tianfu,Li Hefei,Sang Jiaqi,Wang Chao,Cai Rui,Wang Guoxiong,Bao Xinhe
Tuning catalyst microenvironments by electrolytes and organic modifications is effective in improving CO 2 electrolysis performance. An alternative way is to use mixed CO/CO 2 feeds from incomplete industrial combustion of fossil fuels, but its effect on catalyst microenvironments has been poorly understood. Here we investigate CO/CO 2 co-electrolysis over CuO nanosheets in an alkaline membrane electrode assembly electrolyser. With increasing CO pressure in the feed, the major product gradually switches from ethylene to acetate, attributed to the increased CO coverage and local pH. Under optimized conditions, the Faradaic efficiency and partial current density of multicarbon products reach 90.0% and 3.1 A cm −2 , corresponding to a carbon selectivity of 100.0% and yield of 75.0%, outperforming thermocatalytic CO hydrogenation. The scale-up demonstration using an electrolyser stack achieves the highest ethylene formation rate of 457.5 ml min –1 at 150 A and acetate formation rate of 2.97 g min –1 at 250 A.
研究领域:
化学工程
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电化学
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材料科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2019
·
IF 7.015
Kaifeng Wang,Li Gao,Jiafei Liu,Xiangdong Su,Xiaoming Yan,Yan Dai,Xiaobin Jiang,Xuemei Wu,Gaohong He
High-conductive and alkali-resistant alkaline membranes are needed for fuel cells and water electrolysis. In this work, the ether-free poly(biphenyl indole) (PBN) was synthesized by the means of super acid catalysis . Then comb-shaped piperidinium-functionalized PBN (PBN-Pip) membranes were prepared by the incorporations of 1-bromohexyl- N -methylpiperidinium and 1-bromohexane. The comb-shaped long side chains facilitated the formation of wide and connected ion transport channels. The PBN-Pip membrane possessed the conductivity of as high as 108 mS cm −1 at 80 °C. The ether-free backbone and the hexyl spacers endowed the membrane with excellent stability. No degradation can be observed after immersion in 1 M KOH at 80 °C for 1000 h. The single cell with this membrane exhibited the open circuit voltage of 1.02 V and the peak energy density of 404 mW cm −2 at 80 °C. After the cell durability test for 120 h, the ohmic resistance of the cell and the chemical structure of the membrane both had no changes. All these suggest that the comb-shaped PBN membrane is very promising.
研究领域:
材料科学
·
电化学
·
能源技术
✓ 已验证
DOI
高影响因子
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