RSC Advances
·
2020
·Vol. 10
·期 41
·24533-24541
·
IF 3.119
Huiling Chen,Yuehua Wen,Yue Wang,Songtong Zhang,Pengcheng Zhao,Hai Ming,Gaoping Cao,Jingyi Qiu
For high-voltage cycling of lithium-ion batteries, a gel polymer Li-ion conductor layer, P(VDF-HFP)/LiTFSI (PHL) with high electrochemical stability has been coated on the surfaces of as-formed LiCoO2 (LCO) cathodes by a solution-casting technique at low temperature. An LCO cathode coated with around 3 μm thickness of the PHL ultrathin membrane, retains 88.4% of its original capacity (184.3 mA h g−1) after 200 cycles in the 3.0–4.6 V range with a standard carbonate electrolyte, while the non-coated one retains only 80.4% of its original capacity (171.5 mA h g−1). The reason for the better electrochemical behaviors and high-voltage cycling is related to the distinctive characteristics of the PHL coating layer that is compact, has highly-continuous surface coverage and penetrates the bulk of LCO, forming an integrated electrode. The PHL coating layer plays the role of an ion-conductive protection barrier to inhibit side reactions between the charged LCO surface and electrolyte, reduces the dissolution of cobalt ions and maintains the structural stability of LCO. Further, the PHL coated LCO cathode is well preserved, compared to the uncoated one which is severely cracked after 200 cycles at a charging cut-off voltage of 4.6 V.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 65
·52809-52816
·
IF 3.84
Hang Luo,Dou Zhang,Lu Wang,Chao Chen,Jing Zhou,Kechao Zhou
A sandwich-structured composite consisted of a pure poly(vinylidene fluoride-co-hexafluoropropylene) (P(VDF-HFP)) central layer and two BaTiO3–P(VDF-HFP) neighboring layers was developed for high energy storage density. The sandwiched structure effectively enhanced dielectric properties and energy storage capacity of the composites. Breakdown strength and energy storage density of the composite with 35 vol% P(VDF-HFP) central layer reached 315 kV mm−1 and 5.22 J cm−3, which were enhanced by 68% and 125% compared to 187 kV mm−1 and 2.32 J cm−3 of the single layer composite, respectively. The dielectric constant of the composites with sandwich-structure was approximately 3 times higher than the pure P(VDF-HFP) and the dielectric loss was as low as 0.026 at 1 kHz. These results demonstrated that the sandwich-structured ceramics/polymer composite was an effective way to produce high energy density composites.
研究领域:
材料科学
·
电气工程
✓ 已验证
DOI
高影响因子
COMPOSITES SCIENCE AND TECHNOLOGY
·
2020
·
IF 7.094
Qiuying Zhao,Lu Yang,Qirui Peng,Yizhou Ma,Hongli Ji,Jinhao Qiu
Dielectric polymer/composites films with excellent capacitive performance has initiated enormous interest from both academic and industry because of their great potential as flexible and light-weight electrostatic capacitors for modern electric and electronic systems. In this work, we report a novel flexible dielectric composite film consisting of poly (vinylidene fluoride-co-hexafluoropropylene) (P(VDF-HFP)) and dopamine-modified metal-organic frameworks Co 3 [Co(CN) 6 ] 2 (D-M) with excellent capacitive performance for energy storage application . It is found that the D-M show good compatibility with P(VDF-HFP), permitting a high breakdown strength for composites. Meanwhile, the large specific surface area and special porous three-dimensional nanostructure of D-M also has the effect of raising dielectric performance while eliminating the inherent ferroelectric loss of P(VDF-HFP), resulting in considerably promoted discharge energy density . Furthermore, D-M is found to favor the formation of γ-phase in P(VDF-HFP), which is also advantageous to raise the discharge energy density. Upon a small loading of 0.6 wt% D-M, the composites perform a maximum discharge energy density of 11.89 J/cm 3 and discharge efficiency of 71.28% at 350 MV/m, which are 3.04 times and 1.25 times those of the pure P(VDF-HFP) film, respectively. For the first time, we demonstrate that the applicability of flexible D-M/P(VDF-HFP) dielectric composites as advanced electrostatic capacitors, providing a new sight for the design of dielectrics with high capacitive performance.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2023
·Vol. 34
·期 20
·1-9
·
IF 2.8
Yan YuanJie,Fu Qiong,Hou YaFei,Hao Xiaoya,Zhu ZhiBiao,Du Peng,Luo LaiHui,Li WeiPing
To affect or suppress space charge movements is capable of improving the breakdown strength ( E b ) and thus discharge energy density ( U d ) of polymer-based nanocomposites. Herein, partial-fluorinated AOF nanosheets with –F-induced electron traps and –OH groups were designed and prepared. Accompanied with the AOF nanosheet filling, both experimental and simulation results prove the synergistic effects of restricted leakage current channel, prolonged breakdown strength, suppressed secondary collision electron movement and strong interfacial interactions are beneficial in enhancing E b of polymer-based nanocomposites. Consequently, the 1-vol% AOF/P(VDF-HFP) nanocomposite exhibits an excellent E b of 548.4 MV/m and thus a satisfactory U d of 18.5 J/cm 3 . Meanwhile, the charge–discharge efficiency ( η ) of the 1-vol% AOF/P(VDF-HFP) nanocomposite remains 81.1%. The results above suggest a superior performance in comparation with pure P(VDF-HFP) (9.1 J/cm 3 and 72.9%). The primary results might provide a new solution for improving U d and η of nanocomposites.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
SURFACE & COATINGS TECHNOLOGY
·
2018
·
IF 2.906
Qilong Zhang,Yongchang Jiang,Enjie Yu,Hui Yang
Core-shell structured BaTiO 3 @polyaniline (BT@PANI) nanoparticles were synthesized via surface hydroxylation and in-situ polymerization method and were embedded into Poly(vinylidene fluoride- co -hexafluoropropylene) [P(VDF-HFP)] matrix. The dielectric performance as well as thermal behavior of BT@PANI/P(VDF-HFP) nanocomposite films are investigated. The crystallinity increases with increasing the BT@PANI content. Compared with BT particles, the BT@PANI core-shell nanoparticles exhibit notable improvement on dielectric properties . Typically, with a filler content of 20 vol% BT@PANI, the dielectric constant of BT@PANI/P(VDF-HFP) composite film reaches 99.1 at 1 kHz, which is 6.2 times larger than that of 20 vol% BT (16.1) and 9.6 times larger than pristine P(VDF-HFP) (10.3). Enhanced permittivity is generated from the interfacial polarization and the microcapacitor effect provided by the core-shell nanoparticles. Moreover, nanocomposite film maintains a low dielectric loss of 0.21 at 1 kHz. This research offers a solution for fabricating dielectric composite with large dielectric constant and low dielectric loss, which could be beneficial for the improvement of advanced electronic devices.
研究领域:
材料科学
·
电气工程
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2016
·
IF 2.758
Nuoxin Xu,Xingrong Xiao,Hui Yang,Enjie Yu,Qilong Zhang
In this study, TiO 2 nanowires with various aspect ratios were prepared via a precursor-controlled hydrothermal process. Ternary composite films comprised of P(VDF-HFP) polymer, Ag particles and the as-synthesized TiO 2 nanowires were then fabricated. The results reveal that TiO 2 NWs with high aspect ratios (i.e., pa-TiO 2 ) exhibit superiority in enhancing the dielectric constants of composites in comparison with their low-aspect-ratio counterparts (i.e., pr-TiO 2 ). For instance, the dielectric constant of the Ag/pa-TiO 2 /P(VDF-HFP) composite with 30 vol% TiO 2 NWs reaches 33.4 at 100 Hz, which is 42.1% larger than that of Ag/pr-TiO 2 /P(VDF-HFP) sample and 227% higher than pristine P(VDF-HFP). In addition, TiO 2 nanowires also serve as physical obstacles to avoid aggregation of Ag particles. As a consequence, the ternary composites filled with high-aspect-ratio TiO 2 NWs exhibit suppressed dielectric losses (e.g., 0.023 at 100 Hz) and low conductivities, making them promising candidates for applications in integrated capacitors and energy storage devices.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2017
·Vol. 29
·期 2
·1269-1279
·
IF 2.019
Hu Liang,Xia Yuting,Wang Qianqian,Yang Hui,Zhang Qi-long
In this work, a core–shell dendritic CuO@TiO 2 was constructed through a two-step chemical method. Structural analysis confirms the successful coating of TiO 2 on the CuO and the dendritic morphology was maintained after the coating process. The composites were prepared by using ferroelectric P(VDF-HFP) as matrix and synthesized particles as filler. The introduction of fillers influences the melting and crystallization process of the polymer matrix without altering the composition. The insulator layer suppresses the conductivity and dielectric loss by blocking the charge carriers while the composites exhibit improved dielectric constant in the frequency wide range of 10 2 –10 6 Hz and enhanced thermal conductivity. The composite with 20% CuO@TiO 2 exhibits a high dielectric constant of 51.7, low loss of 0.11 at 1 kHz and high thermal conductivity of 0.382 W/mK, showing huge potential for dielectric applications.
研究领域:
材料科学
·
电气工程
·
复合材料
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 97
·79342-79347
·
IF 3.84
Xingrong Xiao,Hui Yang,Nuoxin Xu,Liang Hu,Qilong Zhang
Ag@TiO2 core–shell nanoparticles were synthesized as fillers using a simple vapor-thermal method. Based on the nanoparticles, the P(VDF-HFP)/Ag@TiO2 hybrid films were first prepared by embedding Ag@TiO2 nanoparticles in a poly(vinylidene fluoride co-hexafluoropropylene) [P(VDF-HFP)] matrix. Microstructural and thermal analysis confirmed that Ag nanoparticles had been successfully coated by TiO2 shells and that the thickness of the shell layer was about 8–10 nm. The Ag@TiO2 nanoparticles act as nucleation sites to promote crystallization of the polymer matrix without changing its structure. The P(VDF-HFP)/Ag@TiO2 composite exhibited enhanced dielectric properties over a wide frequency range, and the dielectric permittivity of the polymer nanocomposites is enhanced by ∼300% over the P(VDF-HFP) matrix at a low filler loading of 10 vol%. Moreover, P(VDF-HFP)/Ag@TiO2 also exhibit a higher dielectric constant than P(VDF-HFP)/Ag, P(VDF-HFP)/TiO2 and P(VDF-HFP)/Ag/TiO2 blend composites while maintaining a low loss tangent (below 0.03 at 1 kHz) to achieve a duplex polarization effect.
研究领域:
材料科学
·
电气工程
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2024
·
IF 4.9
Weiduo Fei,Xinwen Ma,Xiandie Zhang,Jie Ji,Xiang Zhou
In this study, the self-assembly method is used to modify Al nanoparticles (Al NPs) with perfluorotetradecanoic acid (PFTD) to obtain Al@PFTD. Based on the C–F…F–C interaction and the hydrogen bond between –CF and –CH, the adsorbed PFTD is used to direct the precipitation of P(VDF-HFP) around modified Al NPs to obtain Al@PFTD@P(VDF-HFP) composite energetic materials. Scanning electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy are used to characterize the prepared samples, which prove a successful preparation process. The prepared Al@PFTD@P(VDF-HFP) is compared with physically mixed Al/P(VDF-HFP) counterparts by thermal analysis, electric ignition and constant-volume combustion tests. Thermal analysis results show that the reaction onset temperature of Al@PFTD@P(VDF-HFP) is 20 °C lower while its heat release is 135% higher. Electric ignition and constant-volume combustion tests show that the ignition delay, combustion time and pressurization rate are 50% shorter, 50% shorter and 40% faster, respectively. The improved energetic performance is mainly due to PFTD-directed precipitation of P(VDF-HFP) around Al NPs. Moreover, the fluorine-containing PFTD also contributes positively to energy density and reactivity through the pre-ignition reaction.
研究领域:
材料科学
·
化学工程
·
高能材料
✓ 已验证
产品关联
DOI
高影响因子
POLYMER
·
2023
·
IF 4.6
Zhuoyuan Zheng,Xudong Zhang,Wenhui Shi,Shishuo Liang,Haichuan Cao,Yanling Fu,Hongwei Wang,Yusong Zhu
Although sodium metal batteries (SMBs) have drawn numerous attentions as the promising candidate for the next-generation rechargeable batteries, various issues hinder their practical applications, e.g., the growth of dendrites and large volume change of Na metal during cycling, etc.. The adoption of gel polymer electrolyte (GPE) is an effective solution to address the safety issues and increase the lifetime of SMBs. In this study, a novel composite membrane consisting of nonwoven fabric as the supporting matrix and poly (vinylidene fluoride-hexafluoropropylene) (P(VDF-HFP)) as the Na + transmission medium is easily fabricated via non-solvent induced phase inversion method. After plasticized by NaClO 4 -based liquid electrolyte , the obtained composite membrane exhibits an enhanced mechanical strength , high uptake to organic liquid electrolyte (115%), high thermal and electrochemical stability, superior ionic conductivity (1.38 mS cm −1 ) and remarkable Na ion transference number (0.47), which has been demonstrated to effectively suppress the growth of sodium dendrite, improve the fast-charging performance and cycling stability of the corresponding SMBs. This work paves a way for the commercialization of GPE in the fast-charging SMBs.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
ACS Applied Energy Materials
·
2022
·
IF 6.959
Ziyue Wang,Huan Liu,Yicheng Peng,Jiyang Xie,Chengding Gu,Wanbiao Hu
Enhancing the breakdown strength (Eb) and polarization of the polymer-based composites through improving the effective interface bonding between the inorganic fillers and polymer matrix is always pursued to achieve high electrostatic energy storage performances. Along with this, paraelectric–ferroelectric (P–F) structured bipolymer PMMA-P(VDF-HFP) was copolymerized and blended to maintain the high Eb but reduce the residual polarization, and meanwhile, potassium triniobate (KNb3O8) rods synthesized by a molten salt (KCl and K2SO4) method were surface-modified using a polydopamine (PDA) shell to form fillers for the fabrication of the composite films that were prepared by a solution casting process. The fabricated PDA@KNb3O8/PMMA-P(VDF-HFP) composite film by filling only a tiny amount of PDA@KNb3O8 (1.0 wt %) exhibits a much enhanced dielectric constant (ε ∼ 9) and polarization (Pmax ∼ 6.9) and large Eb (∼600 MV m–1), therefore giving rise to a high energy density of 15.30 J cm–3 combined with a discharge energy efficiency of 65%. The results herein can be comparative and superior to those of many high-energy storage inorganic–polymer systems that may render this system much potential for dielectric energy storage capacitors.
研究领域:
材料科学
·
电气工程
·
复合材料
·
能量存储
✓ 已验证
DOI
高影响因子
Journal of Physical Chemistry C
·
2021
·
IF 4.126
Shengbiao Sun,Zhicheng Shi,Liang Liang,Tong Li,Shulei Zhang,Wenfeng Xu,Mingli Han,Meiyu Zhang
Paraelectric/ferroelectric bilayer composites are promising candidates for high-performance dielectric capacitors. However, the energy densities of these composites need to be further improved to satisfy the miniaturization of electronic devices. Herein, an Al2O3/P(VDF–HFP) buffer layer is inserted between a paraelectric PMMA layer and a ferroelectric P(VDF–HFP) layer, forming a novel trilayer structure. It is interesting to find that the buffer layer effectively alleviates the huge electric field gap between the P(VDF–HFP) layer and PMMA layer, yielding substantially improved breakdown strengths (>600 kV/mm), which are over 140% that of the bilayer P(VDF–HFP)/PMMA composite (∼425 kV/mm). In addition, the introduction of the buffer layer also results in improved interfacial polarization, hence, the moderately elevated permittivity. Consequently, a high energy density of 10.03 J/cm3, which is about 260% that of the bilayer P(VDF–HFP)/PMMA composite (∼3.9 J/cm3), is achieved at 600 kV/mm. This work offers a facile strategy to achieve dielectric composites with high breakdown strengths, which is illuminating for the design of high-voltage energy-storage capacitors.
研究领域:
材料科学
·
电气工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）