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As the critical component of proton exchange membrane fuel cell (PEMFC), proton exchange membrane (PEM) determine its overall performance. Current PEMs hardly meet the operating requirements of fuel cells, limiting their commercial applications. With the development of nanocomposite technology, nanofibers introduced into PEMs to prepare nanofiber composite proton exchange membranes (NCPEMs) have been widely studied. In an NCPEM, nanofibers can form long-range channels for proton transport, and reinforced skeleton to reach the target performance of PEMFCs. Focusing on NCPEM, this paper reviews on recent progresses in nanofiber preparation and NCPEM preparation techniques. Furthermore, different types of nanofibers incorporated into NCPEMs are reviewed in terms of fiber composition. The challenges and future perspectives regarding NCPEMs are also discussed.

Commercial lithium-ion batteries still undergo safety concerns due to using perilous and flammable liquid electrolytes that are prone to fire and leakage issues. Meanwhile, the development of high energy density lithium-metal batteries with conventional liquid electrolytes has also encountered bottlenecks because of the growth of lithium-dendrites and parasitic reactions. Therefore, the use of flammable liquid electrolytes in lithium batteries is the main obstacle to be overcome, and at the same time, the contradiction between high energy density and high safety for practical applications needs to be addressed. Currently, solid polymer electrolyte has been considered as a promising solution, and hence solid polymer-based lithium batteries have attracted much attention due to their high safety compared to their counterparts. However, its low ionic conductivity, poor mechanical properties, and insufficient cycle life restrict their practical applications. At present, there are fewer comprehensive reviews available on lithium batteries based on polymer electrolyte systems, so it is substantial worthy of summarizing the existing literature and timely apprises of incessantly improving strategies of this field. This review summarizes the ion transfer mechanism and performance requirements of polymer electrolytes for lithium batteries, the classification and design of polymer electrolytes, and the essential principles and characterization for electrode/electrolyte interface construction and the research of composite electrolyte. Finally, the current status and development prospects of polymer electrolytes are briefly summarized and discussed, enabling a foundation for the wide application of solid polymer electrolyte-based batteries.

In this study, Yb3+ and Gd3+ co-doped CeO2 and the corresponding (Li/K)2SO4 composite electrolyte were prepared. The structures and morphologies of Ce0.8Yb0.1Gd0.1O2-α and Ce0.8Yb0.1Gd0.1O2-α-Li2SO4–K2SO4 were investigated using X-ray diffraction (XRD), Raman spectroscopy, and scanning electron microscopy (SEM). The conductivity of Ce0.8Yb0.1Gd0.1O2-α (1550 °C) as a function of time during humidification in a nitrogen atmosphere at 700 °C was investigated. The log(σT) vs. 1000T−1 plots, logσ vs. log(pO2) curves, and fuel cell performances of Ce0.8Yb0.1Gd0.1O2-α (1550 °C) and Ce0.8Yb0.1Gd0.1O2-α-Li2SO4–K2SO4 (1550 °C) were investigated. At 700 °C, Ce0.8Yb0.1Gd0.1O2-α-Li2SO4–K2SO4 (1550 °C) showed a power density of 197 mW cm−2, which is five times higher than that of Ce0.8Yb0.1Gd0.1O2-α (1550 °C).

The composites of CsH2PO4/NaH2PO4/TiO2 were prepared by chemical route. The structural, thermal, and conductive properties were investigated by X-ray diffraction analysis, thermal analysis, and conductivity measurements, respectively. CsH2PO4 shows a superprotonic phase transition from the monoclinic to the cubic phase at 230 °C at which the conductivity increases by four orders of magnitude. The initial dehydration event that occurred in CsH2PO4 was observed at 250 °C and the dehydration behavior also decreased at high temperatures due to the additives. The performance of CsH2PO4 was improved based on conductivity and stability by adding TiO2 and NaH2PO4. 5CsH2PO4/3NaH2PO4/2TiO2 and 6CsH2PO4/2NaH2PO4/2TiO2 were found to have the lowest weight loss compared to other composites. The conductivity also increases up to 1.5 orders of magnitude at lower temperatures. The conductivity was found to be highest for the composite 8CsH2PO4/1NaH2PO4/1TiO2 with a value of 1.4 × 10−2 S cm−1.

The composite of samarium doped ceria (Sm0.2Ce0.8O2-delta, SDC) and co-doped barium cerate (BaZr0.1Ce0.7Y0.1Yb0.1O3-delta, BZCYYb) is prepared by mechanical mixing and investigated as electrolyte for intermediate temperature solid oxide fuel cells (IT-SOFCs). Coexistence of SDC and BZCYYb are observed for composite electrolyte by X-ray diffraction after sintering at 1500 degrees C for 5 h, while the slight deviation of the diffraction peak indicating the element diffusion between two phases. The scanning electron microscope and electron probe microanalyzer results demonstrate that small BZCYYb grains disperse uniformly around the grains of SDC, limiting the growth of SDC grains and decreasing the average grain size of composite electrolyte. Impedance spectroscopy measurement reveals that the grain boundary resistance can be significantly reduced by about an order of magnitude through adding 15-30 wt. % BZCYYb to SDC. Single cells based on the composite electrolyte are fabricated using nickel cermet (Ni-SDC) anode and perovskite (La0.6Sr0.4Co0.2Fe0.8O3-delta, LSCF) cathode., Relatively high open circuit voltage (OCV), much lower polarization resistance and encouraging high power density are obtained for cells with composite electrolyte compared to those with single SDC electrolyte. Among all of the samples, single cell based on 15 wt. % BZCYYb-85 wt. % SDC composite electrolyte exhibits the lowest total resistances of 0.641 Omega.cm(2) and the highest peak power densities of 0.56 W. cm(-2) at 600 degrees C. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

A SrCe 0.7 Zr 0.2 Eu 0.1 O 3-α (SCZE-SG) electrolyte was successfully fabricated by a sol-gel method using Eu 2 O 3 , Sr(C 2 H 3 O 2 ) 2 2 O, (NH 4 ) 2 Ce(NO 3 ) 6 and Zr(NO 3 ) 4 ·5H 2 O as raw materials and was subsequently reacted with NaCl/KCl. The obtained materials were characterized by XRD and SEM techniques. XRD results showed that SCZE-SG and NaCl/KCl did not chemically react. The SEM images revealed that the particle size of SCZE-SG is uniform, and NaCl/KCl is coated on the surface of SCZE-SG, acting as a binder in SrCe 0.7 Zr 0.2 Eu 0.1 O 3-α -NaCl-KCl (SCZE-SG-NK). The oxide ion and protonic conduction of SCZE-SG was studied using gas concentration cells, and the results indicate that the durability of the fuel cell based on SCZE-SG-NK exhibits excellent cell performance with a maximum power output density of approximately 0.58 W cm −2 during a 40-h operation at 700 °C.

Li-garnet Li7La3Zr2O12 (LLZO) is a promising solid electrolyte for lithium metal batteries owing to its excellent stability and high ionic conductivity. However, there exists serious lithium dendrite problem in LLZO electrolyte under elevated current density, easily leading to internal short-circuit and poor cycling performance. In this work, we demonstrated that Ta-doped LLZO with 4 wt% MgO additive delivered superior endurance to lithium dendrite due to its improved mechanical properties and lower electronic conductivity. The critical current density (CCD) of LLZTO-MgO composite electrolyte reached as high as 1.95 mA⸳cm−2 at room temperature (RT). It also realized stable lithium plating/stripping performance for 1000h under 0.5 mA⸳cm−2. Moreover, the full cell paired with LiNi0·6Co0·2Mn0·2O2 cathode exhibited better cycling stability especially at a high rate. Our work provided an alternative strategy for dendrite-suppression in solid electrolyte besides interfacial modification.

Recently, a reusable polymerized ionic liquid/carbon nanoparticle composite electrolyte was developed and effectively applied to a variety of oxidative transformations. The efficient recovery of the composite material and its application in subsequent electroorganic conversions without sacrificing yield adds to the sustainability of the protocol. Herein, we describe our efforts to expand the operational window of the composite electrolyte to include cathodically initiated processes occurring at potentials up to −2.6 V. The results indicate that the composite electrolyte is applicable to reductive processes, but the scope of transformations appears to be limited.

In the present study, electrical properties of a composite electrolyte composed of a BaZr 0.8 Y 0.2 O 3 -δ (BZY) and a perspective of defect chemistry. A DFT first-principles calculation further confirmed that proton transfer in molten carbonates was a low-energy process.

Li-ion ceramic electrolyte material is considered the key for advanced lithium metal batteries, and garnet-type oxides are promising ceramic electrolyte materials. To disentangle the thinness-strength dilemma in garnet-type Li6.4La3Zr1.4Ta0.6O12 (LLZTO) electrolyte, we designed and successfully synthesized a ceramic–ceramic composite electrolyte, i.e. a honeycomb-Al2O3 pellet supported LLZTO membrane. The honeycomb-Al2O3 pellet acts as a supporter to the thin LLZTO membrane and makes the whole composite electrolyte strong enough, while the straight holes in the Al2O3 supporter can be filled with liquid electrolyte and acts as channels for Li+ transportation. Such a composite design eliminates the concern over the LLZTO membrane's fragility, and keeps its good electrical property.

Development of low-temperature solid oxide fuel cells (LTSOFC) is now becoming a mainstream research direction worldwide. The advancement in the effective electrolyte materials has been one of the ...

Inorganic membranes for high temperature CO2 separation has potential applications in clean energy delivery for CO2 capture. In this work, the gas tight oxygen ion conducting perovskite and carbonate composite electrolyte hollow fibre membranes were developed for CO2 separation at high temperatures. For this purpose, the La0.6Sr0.4Co0.2Fe0.8O3−α (LSCF) perovskite hollow fibre was firstly prepared as the porous support to impregnate and immobilize the carbonate phase. The composite electrolyte hollow fibre membranes were characterised by SEM, XRD, room-temperature gas leakage detection and CO2 permeation test at temperature regime from 500 to 900 °C. The maximum CO2 flux measured reached 1.0 mL cm−2 min−1 at 900 °C, which was improved by a factor up to 5 when compared with the previously developed membranes due to the much thinner separating layer achieved in the current membrane.

In this study, dense composite electrolytes with different H3PO4 doping levels were fabricated. The conductivity property is optimized giving consideration to the influence of H3PO4 doping level. The result of SEM image indicates that the composite of 1P1S-7 is sufficiently dense. The conductivities increase with the order: σ (1P1S)

In this work, the effect of copper, iron and cobalt oxides on electrochemical properties of lithiated NiO cathodes was reported in low temperature solid oxide fuel cell (LT-SOFC) with ceria-carbona ...

Pr2NiO4-Ag composite was synthesized and evaluated as cathode component for low temperature solid oxide fuel cells based on ceria-carbonate composite electrolyte. X-ray diffraction analysis reveals ...

Low temperature solid oxide fuel cells (SOFCs) with metal oxide composite cathode on the ceria–carbonate composite electrolyte have shown promising performance. However, the role of individual elem ...

A co-doped ceria-carbonate (Ce0.8Sm0.2-xCaxO2-delta-Na2CO3) has been synthesized by a co-precipitation method. The detailed electrochemical characterizations (e.g. impedance spectra, polarization c ...

Dense β″-alumina electrolyte tubes with thickness less than 50 μm were slip cast on a porous substrate of β″-alumina. The resistance of the composite electrolyte was measured by a DC method. The area specific resistance of a thin layer electrolyte versus the full thickness electrolyte was lower by a factor of 1.6. The components of cell resistance were determined. It was concluded that interfacial resistance is a dominant factor in the electrolyte resistance.

The proton-conductive MH 2 PO 4 /SiP 2 O 7 -based composites (M = K, Rb, Cs) were synthesized, and their structure and proton conductivity were investigated at intermediate temperatures. For all MH 2 PO 4 /SiP 2 O 7 -based composites, the chemical reaction between MH 2 PO 4 and SiP 2 O 7 has proceeded during the heat treatment at 220 °C for 1 h, resulting in the formation of MH 5 (PO 4 ) 2 . The heat-treated composites exhibited higher conductivity than MH 2 PO 4 due to the new conduction phase of MH 5 (PO 4 ) 2 , regardless of the alkaline metal species. The electrolytes of MH 5 (PO 4 ) 2 /SiP 2 O 7 composites (M = K, Rb, Cs) were also fabricated so as to compare the conductivity with almost the same charge carrier concentration. It is noted that their conductivity is independent of the alkaline metal species.

New lithium ion composite electrolyte, LiI–Li 2 S–La 2 O 2 S m ( m = 1, 2) was synthesized from the binary Li 2 S–LaOI system through solid state reaction. The lithium ion conductive property was investigated by AC impedance spectroscopy. And the highest conductivity of the obtained electrolyte at room temperature was found to be 3.0 × 10 − 6 S cm − 1 . The notable ionic conduction was attributed to the in situ formed amorphous LiI.

The conductivity of Na 4 Zr 2 Si 3 O 12 (NZS) has been measured containing a ferroelectric dispersant, PZT, to form a composite electrolyte. The variation of conductivity with preparation method, dispersant content and sintering regime has been investigated. NZS made by sol-gel had a lower conductivity than that made by mechanical mixing. At 300°C the maximum conductivities were 4×10 −5 and 4×10 −4 S cm −1 respectively. Adding PZT did not enhance the conductivity at all. Thermal history is the most important factor determining the conductivity.

D.C. conductivity, susceptibility of pure and α-Fe 2 O 3 (β-AgI) composite electrolyte has been measured below room temperature. It is found that the Morin transition temperature of α-Fe 2 O 3 is decreased by the addition of β-AgI. The results of Mossbauer spectra quantitatively coincide with these investigations.

A light microscopy study has led to the discovery of a liquid phase within the discharge product of Li/I2 cells with P2VP-coated lithium anodes. The liquid phase apparently results from a reaction between lithium, P2VP, and iodine, and is capable of transporting lithium ions. The improved performance observed for Li/I2 batteries with P2VP coated anodes is attributed to the presence of this liquid electrolyte. Spectral analysis suggests that the liquid electrolyte is most likely a 2-iodoethyl aliphatic amine capable of solvating or complexing with lithium ions.