Journal of Materials Chemistry C
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2014
·Vol. 3
·期 6
·1250-1260
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IF 0
Y. Feng,W. L. Li,Y. F. Hou,Y. Yu,W. P. Cao,T. D. Zhang,W. D. Fei
Polymer based composites with high dielectric constant were successfully fabricated using BaTiO3 nanowires with high aspect ratio as inorganic filler and PVDF-HFP as polymer matrix. PVDF-HFP/BaTiO3 nanoparticles composites were also prepared as a contrast. The BaTiO3 nanowires were synthesized via one-step hydrothermal method. The BaTiO3 nanowires and its two types of composites were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy and transmission electron microscopy. For the composites, breakdown strength measurements, tensile tests and broadband dielectric spectroscopy analyses were also carried out. The results show that the two types of fillers are homogeneously dispersed in the matrix. The dielectric constant of composites filled by BaTiO3 nanowires is larger than that filled by BaTiO3 nanoparticles at the same content. Stronger interfacial polarization was found in PVDF-HFP/BaTiO3 nanowire composites. Two theoretical models were employed to predict the dielectric constants of composites, and the experimental data were consistent with the estimated trend. The enhanced dielectric properties of PVDF-HFP/BaTiO3 nanowire composites are attributed to the superior interfacial polarization and high aspect ratio of BaTiO3 nanowires.
研究领域:
材料科学
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电气工程
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DOI
CHEMICAL ENGINEERING JOURNAL
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2022
·
IF 16.744
Ru Wang,Xiaoyu Xie,Chunxiang Xu,Yi Lin,Daotong You,Jinping Chen,Zhuxin Li,Zengliang Shi,Qiannan Cui,Mingliang Wang
Piezoelectric field engineering has been recently proved to restrain the photogenerated carrier recombination both in the bulk and on the surface of photocatalyst. Herein, we proposed a bi-piezoelectric ZnO nanorods (NR)/PVDF-HFP spongy film that can utilize water flow vibration to boost the photocatalytic degradation of organic dye. The composite photocatalyst can be deformed by water flow to generate an integrated piezoelectric field from PVDF-HFP and ZnO NR , which can considerably drive the separation and transfer of photogenerated charge carriers in ZnO NR. As a result, the ZnO NR/PVDF-HFP spongy film shows a ∼ 3 fold increase in reaction rate constant of degrading methyl orange (MO) with irradiation as flow speed increases from 200 rpm to 1000 rpm. A model about the bi-piezoelectric effect of ZnO NR/PVDF-HFP was configurated according to a series of characterization by piezoelectric force microscopy (PFM) and photoluminescence (PL). This work demonstrates the contribution of the bi-piezoelectric effect to photocatalytic water decontamination and provides a promising strategy to use dual-sustainable energy— solar and water energy.
研究领域:
材料科学
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环境科学
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2023
·
IF 15.1
Jiangchao Chen,Guisheng Zhu,Kunpeng Jiang,Huarui Xu,Yunyun Zhao,Hu Wang,Pengfei Pang,Yiran Bai,Peipei Wang,Haining Wu
Safety concerns such as lithium dendrite growth, leakage and volatilization regularly plague conventional liquid lithium metal batteries. However, solid polymer electrolytes can mitigate these issues due to their chemical and electrochemical stability. In this paper, we show that the construction of porous structures gives PVDF-HFP based polymers excellent solution retention, quick Li + transport channels, and ultra-long Li-symmetric cycle stability. PVDF-HFP based electrolyte membrane with porous structure exhibits excellent electrolyte retention (129.5 %) and superior ionic conductivity (2.4 × 10 -3 S cm −1 at 20 ℃). In addition, Lithium-symmetric half battery uses the DPH250 porous electrolyte film to stably last more than 2000 h during the lithium plating/stripping process. DI regulation of PVDF-HFP electrolyte membrane is beneficial to achieve uniform lithium deposition, and better solve the interface problems existing in solid state batteries. LiFePO 4 /DPH250-LiPF 6 /Li batteries exhibit stable cycling performance and reversible specific discharge capacity, suggesting a potential strategy for stabilizing lithium metal batteries.
研究领域:
材料科学
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能源存储
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Shangheng Jiang,Shiqiang Liang,Chunxiao Hu,Yuanfang Fan,Zhongmin Su,Zhi Geng,Chi Wang
Membrane Distillation (MD) technology stands out for its cost-effectiveness and sustainability in diverse applications, such as high-salinity wastewater treatment and seawater desalination. However, conventional MD membranes frequently encounter challenges associated with inadequate permeate flux and insufficient anti-wetting performance. In the present study, we fabricated a series of ZIF-CoZn@PVDF-HFP composite nanofiber membranes with a core–shell structure via coaxial electrospinning. Here, PVDF-HFP functions as the core, while a blend of bimetallic Zeolitic imidazolate framework ZIF-CoZn nanoparticles and PVDF-HFP constitutes the shell. Through the utilization of the coaxial technology, functional nanoparticles achieve uniform and stably dispersed on the nanofiber surface, leading to the creation of a secondary rough structure in addition to the inherent roughness of single-nozzle electrospinning. This results in a surface with a 3D-hierarchical structure. The significantly amplifies the evaporation area on the surface of the composite nanofiber membrane, thereby bolstering the permeate flux in the MD process. Additionally, the incorporation of bimetallic ZIF-CoZn nanoparticles, recognized for their superior hydrophobicity and low thermal conductivity, improves the anti-wetting and heat-insulating properties of the composite nanofiber membrane, further advancing permeate flux performance. Using a 35 g L −1 NaCl as the feed solution, the optimal 1 % ZIF-CoZn@PVDF-HFP composite nanofiber membrane demonstrated a permeate flux of 21.8 L m −2 h −1 , coupled with a salt rejection rate exceeding 99.9 %. Even during long-term MD testing, it maintained excellent insulation and anti-wetting capabilities. Our research offers a convenient and effective approach for fabricating anti-wetting composite nanofiber membranes.
研究领域:
材料科学
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环境工程
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DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2022
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IF 14.224
Mengnan Chai,Wangshu Tong,Zhihao Wang,Zhensheng Chen,Yuancheng An,Yihe Zhang
Piezocatalysis driven by a gentle force possesses broad application prospects for degrading organic pollutants , sterilisation, wound healing and tissue recovery. The flexible and industrially scalable poly(vinylidene fluoride) (PVDF) film is commonly used in piezocatalysis. However, under gentle force action, PVDF composite-based piezocatalysis is poor. Herein, a flexible porous film based on poly(vinylidene fluoride)-hexafluoro propylene (PVDF-HFP) is enhanced with Fenton fillers (α-Fe 2 O 3 nanoparticles). α-Fe 2 O 3 nanoparticles improve the piezoelectric catalysis performance of PVDF-HFP by the β-phase enhancement and provide Fe 3+ to react with H 2 O 2 generated by the piezoelectric film itself, leading to an additional Fenton reaction . Meanwhile, the Fe 3+ /Fe 2+ cycle in the Fenton process accelerates under the piezoelectric field, promoting the Fenton reaction for 6.9% degradation improvement. The study on Fe 2 O 3 /PVDF-HFP porous film with the piezo–Fenton reaction under flowing water may help promote new piezocatalysis designs with high efficiency for self–powered environmental purification.
研究领域:
环境科学
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材料科学
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DOI
PubMed
高影响因子
Materials
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2019
·Vol. 12
·期 17
·2813
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IF 2.972
Haijuan Li,Ling Li,Shuaizhi Zheng,Xinming Wang,Zengsheng Ma
To improve the thermal shrinkage and ionic conductivity of the separator for lithium-ion batteries, adding carboxylic titanium dioxide nanofiber materials into the matrix is proposed as an effective strategy. In this regard, a poly(vinylidene fluoride-hexafluoro propylene)/dibutyl phthalate/carboxylic titanium dioxide (PVDF-HFP/DBP/C-TiO2) composite separator is prepared with the phase inversion method. When the content of TiO2nanofibers reaches 5%, the electrochemical performance of the battery and ion conductivity of the separator are optimal. The PVDF-HFP/DBP/C-TiO2(5%) composite separator shows about 55.5% of porosity and 277.9% of electrolyte uptake. The PVDF-HFP/DBP/C-TiO2(5%) composite separator has a superior ionic conductivity of 1.26 × 10−3S cm−1and lower interface impedance at room temperature, which brings about better cycle and rate performance. In addition, the cell assembled with a PVDF-HFP/DBP/C-TiO2separator can be charged or discharged normally and has an outstanding discharge capacity of about 150 mAh g−1at 110 °C. The battery assembled with the PVDF-HFP/DBP/C-TiO2composite separator exhibits excellent electrochemical performance under high and room temperature environments.Keywords:TiO2nanofiber;PVDF-HFP;composite separator;phase inversion;thermal shrinkage;ionic conductivity
研究领域:
材料科学
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电化学
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DOI
PubMed
高影响因子
International Journal of Electrochemical Science
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2023
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IF 1.5
Huabin Guo,Shengwen Zhong,Liping Chen,Guanghuai Peng,Fang Fang Wang,TingTing Yan,Jingwei Hu
The PVDF-HFP/PMMA/CMC blended solid polymer prepared by solvent volatilization method with PVDF-HFP as host polymer matrix and PVDF-HFP/PMMA as blended membrane and then PVDF-HFP/PMMA modified by coating carboxymethyl cellulose (CMC) was introduced in this study to overcome the shortcomings of organic solvent - based liquid electrolyte in lithium-ion batteries. The synthesized copolymers were characterized by FTIR, TGA, XRD, and the results show that PMMA can be well dispersed in PVDF-HFP solution and the addition of CMC can reduce the crystallinity of the polymer membrane, which accelerates the movement of the polymer chain segments and improves the migration rate of lithium-ions. The electrical conductivity of the gel polymer was investigated by AC impedance, and the room temperature ionic conductivity of the gel polymer was up to the order of 10 -3 S·cm -1 , and the electrochemical stability window was 4.8 V. The polymer lithium-ion battery assembled with LiCoO 2 as cathode and lithium sheet as anode has good cycle stability. The lithium metal polymer cell delivered discharge specific capacity with 162.52 mAh.g -1 at the first cycle, and these properties indicate that the modified gel polymer has applicative prospect in polymer lithium-ion batteries.
研究领域:
材料科学
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电化学
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能源存储
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DOI
高影响因子
ACS Applied Energy Materials
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2024
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IF 5.4
Mingming Cui,Hong Sun,Zhichao Xue,Qiang Li,Tianyu Zhang,Qunying Kang
Using gel polymer electrolytes (GPEs) instead of liquid electrolytes is a sensible and effective strategy for safety reasons. A GPE membrane was prepared by UV-curing using poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) as the polymer substrate material and an optimized ratio. The GPE membrane exhibited good flexibility and a higher ionic conductivity (σ = 0.63 mS cm–1). The RuO2@C/GPE/Li (abbreviated as S-GPE) battery is employed to demonstrate the electrochemical performance of GPE. The battery exhibits an Rct of 255.9 Ω, accompanied by a lack of cycle stability, with a cycle life of only 110 h. The results indicate that it is challenging to enhance the battery’s overall performance by solely improving the internal transfer performance of the electrolyte and ignoring the high interface impedance caused by the “solid–solid” contact at the electrolyte–electrode interface. Based on these findings, a straightforward one-step method is adopted to combine GPE with the air cathode by in situ photopolymerization and assemble it into RuO2@C-GPE/Li (abbreviated as I-GPE) battery used to demonstrate the electrochemical performance of the integrated GPE. The Rct value of the battery is 89.66 Ω, with a notable improvement in cycle stability. The battery’s cycle life is 940 h, which is 8.5 times that of the sandwich structure lithium–oxygen battery. The results indicate that preparing an integrated GPE by in situ photopolymerization of the electrolyte electrode is a straightforward and effective method to improve poor interfacial compatibility and can provide a theoretical basis for subsequent in-depth research.
研究领域:
材料科学
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电化学
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DOI
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
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2021
·Vol. 168
·期 2
·022504
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IF 4.316
Shahid Khan,Chaoyan Fang,Yecheng Ma,Mahmood ul Haq,Mohammad Nisar,Gang Xu,Yong Liu,Gaorong Han
The aim of the study was to determine the effect of inorganic core-shell SiO2 nanoparticles modified with polymethyl methacrylate (PMMA) layer, on the optical and electrochemical properties of poly vinylidenefluoride-co-hexafluoropropylene (PVDF-HFP) gel polymer electrolyte (GPE). The core-shell SiO2 nanoparticles were first modified with PMMA to improve its dispersibility and compatibility in the polymer matrix. The morphology and structural properties of the core-shell SiO2 nanoparticles before and after modification were characterized by XRD, FTIR and SEM analysis. Then the modified SiO2 nanoparticles were used to prepare the composite GPE, composed of chemically modified core-shell structured SiO2-PMMA and PVDF-HFP polymer matrix. The transformation of nano-silica to SiO2-PMMA nanoparticles shows the better compatibility of PMMA and PVDF-HFP that favours the silica to be well dispersed in the organic matrix and significantly improve the doping effect. Various concentrations of modified SiO2-PMMA were used to dope PVDF-HFP GPEs. The results indicate that the 10% doping shows the highest ionic conductivity i.e. 2.22 × 10−3 s cm−1. In addition, the composite GPEs show the high transmittance and good thermal stability; therefore it can add important insight into developing high-performance materials for electrochromic devices.
研究领域:
材料科学
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电化学
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DOI
高影响因子
Journal of Central South University
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2022
·Vol. 29
·期 9
·2980-2990
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IF 2.392
Wang Zhen-yu,Li Cong,Huang Ying-de,He Zhen-jiang,Yan Cheng,Mao Jing,Dai Ke-hua,Zheng Jun-chao
With increasing demand on energy density of lithium-ion battery, wide electrochemical window and safety performance are the crucial request for next generation electrolyte. Gel-electrolyte as a pioneer for electrolyte solidization development aims to solve the safety and electrochemical window problems. However, low ionic conductivity and poor physical performance prohibit its further application. Herein, a fast-ionic conductor (Li 2.64 (Sc 0.9 Ti 0.1 ) 2 (PO 4 ) 3 ) (LSTP) was added into poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) base gel-electrolyte to enhance mechanical properties and ionic conductivity. Evidences reveal that LSTP was able to weaken interforce between polymer chains, which increased the ionic conductibility and decreased interface resistance during the cycling significantly. The obtained LiFePO 4 /hybrid gel-electrolyte/Li-metal coin cell exhibited excellent rate capacity (145 mA·h/g at 1 C , 95 mA·h/g at 3 C , 28 °C) which presented a potential that can be comparable with commercialized liquid electrolyte system.
研究领域:
材料科学
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能源存储技术
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高影响因子
CHEMICAL ENGINEERING JOURNAL
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2024
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IF 13.3
Mohammed Karama Alsebaeai,Abdul Latif Ahmad,Boon Seng Ooi
In this research, the construction of a highly wetting-resistance membrane surface was achieved through an integrated dip-coating phase inversion process to accelerate water mass transfer of membrane distillation (MD). The synergistic effect of incorporating reduced graphene oxide (rGO) embedded Poly (vinylidene fluoride- co -hexafluoropropylene) (PVDF-HFP) on the surface of a PVDF hollow fiber support membrane using a dilute coating solution was studied. Various loadings of rGO nanosheets were incorporated into the dilute PVDF-HFP coating to systematically investigate its physicochemical characteristics, including surface morphology, hydrophobicity and wetting resistance which could be analyzed using scanning electron microscopy (SEM), atomic force microscopes (AFM), water contact angle (WCA), porosity measurement, pore size, x-ray diffraction (XRD), and liquid entry pressure (LEP) tests. The membrane separation performance for desalination was evaluated using direct contact membrane distillation (DCMD) process. Compared to the PVDF hollow fiber support membrane, the rGO-embedded PVDF-HFP coating layer demonstrates outstanding enhancements. The membrane surface exhibits enhanced hydrophobicity, as evidenced by an increased WCA from 105.37° (for the PVDF support membrane) to 148.37° (for the rGO/PVDF-HFP composite membrane). Additionally, the water permeability significantly improved, achieving a water flux of 25.9 kg m -2 h -1 (compared to 11.55 kg m -2 h -1 for the PVDF support membrane). These enhancements occur without compromising NaCl rejection, which remains consistently above 99.99 % (3.5 wt% NaCl aqueous solution at a feed temperature of 70 °C and a permeate temperature of 18 °C). These findings underscore the potential of rGO/PVDF-HFP in enhancing MD performance. The composite HF membrane demonstrates remarkable stability during continuous MD operation over a 48 h period. Pore wetting is effectively avoided, indicating that the composite membrane has superior resistance to wetting and excellent stability.
研究领域:
材料科学
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环境工程
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高影响因子
Advanced Materials Interfaces
·
2018
·Vol. 5
·期 5
·1701147
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IF 4.834
Shamshad Ali,Chao Tan,Muhammad Waqas,Weiqiang Lv,Zhaohuan Wei,Songhao Wu,Bismark Boateng,Jingna Liu,Junaid Ahmed,Jie Xiong,John B. Goodenough,Weidong He
Toward high-temperature lithium-ion batteries, adding inorganic materials are proposed as an effective strategy. However, inorganic particles tend to aggregate in the polymer matrix, causing degradation in battery performance. Here, a PVDF-HFP/colloidal Al 2 O 3 composite separator is prepared with a phase inverse method. The colloidal Al 2 O 3 particles well dispersed in the PVDF-HFP polymer matrix substantially enhance the mechanical strength of the PVDF-HFP separator. The PVDF-HFP/colloidal Al 2 O 3 composite separator owns a high electrolyte uptake of 372%, a high ionic conductivity of 1.3 × 10 −3 S cm −1 at 80 °C and delivers high capacity retention of 95.6% after 100 charge–discharge cycles at 0.5 C. In addition, PVDF-HFP/colloidal Al 2 O 3 separator only has a 4.5% thermal shrinkage at 150 °C and exhibits high electrochemical performances upon annealing at 140 °C.
研究领域:
材料科学
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能源技术
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DOI
高影响因子
危险品化学品经营许可证（带存储）