Fengjing Jiang

• PhD
• Senior Researcher at CIC Energigune

This study integrates electrochemical testing and physical characterization to systematically examine the impact of pretreatment processes on the performance of titanium-based porous transport layers (PTLs) in proton exchange membrane water electrolyzers (PEMWEs). It is revealed for the first time that surface defects in PTLs are the primary cause...

Sulfonated poly(ether ether ketone) (SPEEK) is a potential low-cost candidate to replace fluorine-based Nafion membranes in some redox flow batteries (RFBs). In this work, the ionic conductivity of SPEEK membranes is increased almost fourfold by conducting a well-controlled irreversible swelling of the membrane. Atomic Force Microscopy images and s...

The proton exchange membrane water electrolyzer (PEMWE) is a crucial device for hydrogen production, both currently and in the future, due to its environmentally friendly, safe, efficient, and long-lasting characteristics, as well as its rapid start-up capabilities, which confer significant commercial value. Proton conduction resistance of the anod...

Proton exchange membrane water electrolysis (PEMWE) is regarded as one of the most suitable technologies for integrating with renewable energy sources due to its fast response, high efficiency, and compact structure, and its products are carbon-free and can be stored as energy carriers. However, current research predominantly concentrates on optimi...

Proton exchange membrane water electrolysis (PEMWE) is a vital power to gas (P2G) technology due to its rapid response, which is superior to alkaline cells. However, thin membranes pose degradation risks at high temperatures, making thermal management crucial. This study develops a 1 Nm3/h PEMWE system, establishing a digital twin model based on el...

Liquid water is sometimes found exhausted from the anode exit of an air-cooled proton exchange membrane fuel cell (ACFC) even if dry hydrogen is input as fuel while its utilization rate is kept constant, i.e., having the forced convection of H 2 in the anode. The anode liquid water accumulation may block the hydrogen into the anode catalyst layer (...

Porous ion-selective membranes are promising alternatives for the expensive perfluorosulfonic acid membranes in redox flow batteries. In this work, novel non-ionic porous polyvinylidene fluoride-hexafluoro propylene membranes are designed for iron-lead single-flow batteries. The membranes are prepared using a multiple template approach, involving s...

Currently, there are only some general concepts about the performance difference between an LT-PEMFC (low temperature proton exchange membrane fuel cell) and an HT-PEMFC (high temperature proton exchange membrane fuel cell), i.e., no literature has been found to conduct direct comparisons between them. In this research, for the first time, accordin...

Ion-selective membranes based on non-ionic polymers are promising for redox flow batteries due to their superior chemical stability and low cost. In this work, a poly(vinylidene fluoride) (PVDF) ion-selective membrane is successfully prepared using a solvent-controlled swelling method, where Nafion is used as a channel-forming promoter. The influen...

Nafion, as the mostly used proton exchange membrane material in vanadium redox flow batteries (VRFBs), encounters serious vanadium permeation problems due to the large size difference between its anionic nanophase (3-5 nm) and cationic vanadium ions (∼0.6 nm). Bulk hybridization usually suppresses the vanadium permeation at the expense of proton co...

With the increasing demand of renewable energy, large-scale energy storage technology has attracted extensive attention. Vanadium redox flow battery (VRFB), benefiting from its adjustable capacity, high safety and long life, has become one of the fastest developing batteries for large-scale energy storage. Ion exchange membrane is a key component o...

Porous membranes based on low-cost, chemically robust and non-ionic polymers are found to be promising as ion-selective membranes in redox flow batteries. Herein, we fabricate a dual-porous structured membrane where micro and macro pores are formed in the Nafion/poly(vinylidene fluoride) hybrid matrix. The dual-porous structure of the membranes is...

Low‐cost and high‐performance ion‐conducting membranes are of urgent need for the large‐scale launch of vanadium redox flow batteries. In this work, sulfonated poly(ether sulfone) (SPES) with extremely low sulfonation degree of 5% is utilized to prepare ion‐selective membranes, which possess significantly enhanced chemical stability as compared wit...

Finely controlled swelling is reported as a universal and facile method to construct abundant ion-selective channels in polymer membranes. In this work, excellent ion-selectivity of H⁺/Vⁿ⁺ is achieved by using a swelling-solidification method based on sulfonated poly(ether sulfone) (SPES) with only 20% sulfonation degree. The swelling degree of the...

To sufficiently improve the electrical conductivity of composite bipolar plates is crucial for their application in fuel cells and redox flow batteries. Eliminating the resin-rich layer on the surface of composite bipolar plates turns to be an effective approach. In this work, graphite/resin composite bipolar plates with advanced performance and du...

Blending perfluorosulfonic acid (e.g. Nafion) with other polymers is an effective approach to reduce the cost and adjust the properties of durable proton conducting membranes. In particular, poly(vinylidene fluoride) (PVDF) composites have attracted much attention because of its outstanding chemical/thermal stability and it can enhance the barrier...

Redox flow battery has become one of the most promising technologies for large-scale energy storage. However, as a key component, bipolar plate is still under development to achieve high electrical conductivity and sufficient flexural strength simultaneously. With this purpose, an innovative low-carbon-content bipolar plate with hybrid conductive m...

High ion selectivity and mechanical strength are critical properties for proton exchange membranes in vanadium redox flow batteries. In this work, a novel sulfonated poly(ether sulfone) hybrid membrane reinforced by core-shell structured nanocellulose (CNC-SPES) is prepared to obtain a robust and high-performance proton exchange membrane for vanadi...

Carbon aerogel modified graphite felt is prepared as electrodes for vanadium redox flow batteries. Morphology and the nano-porous structure of the carbon-carbon composite electrode is characterized. Properties such as cyclic voltammetry, electrochemical impedance and battery performance of the carbon-carbon composite electrodes are investigated. Th...

To develop cost-effective ion-exchange membrane is of great importance for the large-scale industrialization of flow batteries. In this work, a novel method is proposed to prepare ion-selective microporous membranes based on non-electrolytic polymers. For the first time, poly (vinylidene fluoride) (PVDF) membranes with symmetric microporous structu...

To develop high ion-selective proton exchange membranes is of great importance for vanadium redox flow batteries. In this work, a novel asymmetric porous sulfonated poly (ether sulfone) (SPES) membrane with ultra-high ion selectivity is prepared via ionic-liquid-induced phase separation. The characteristics of the prepared porous membrane, includin...

High performance nitrogen-doped graphite felts are successfully prepared via urea hydrothermal treatment at low temperatures below 180°C and is demonstrated as enhanced electrodes for vanadium redox flow batteries. Effect of urea hydrothermal treatment temperature on the nitrogen-bonding configurations is investigated. Properties of the modified gr...

The photo-crosslinked polyamide 6 (PA 6)-LiCl nanofibrous membranes (NFMs) with presence of benzophenone (BP) and triallyl isocyanurate (TAIC) have been successfully manufactured as novel desiccant materials. The FTIR spectra illustrated the crosslinking of the PA 6. The sorption isotherms suggested that the crosslinked PA 6-LiCl NFMs could sorb 0....

Bipolar plates possessing both high electrical conductivity and mechanical strength has been urgently required for redox flow batteries and fuel cells. Contrary to the conventional method of increasing carbon content to maximize the bipolar plate's electrical conductivity, a novel low‐carbon‐content design based on the bridging effect of graphene i...

Suppressing vanadium ions crossover is a top priority in the development of membranes for vanadium redox flow battery (VRFB). One method is to dope inorganic fillers into polymer matrix, which usually decreases membrane's ion conductivity. In this work, sulfated zirconia (S–ZrO2) is synthesized as a novel additive doped in sulfated poly (ether sulf...

Polyamide 6-LiCl (PA 6-LiCl) electrospun nanofibrous membranes (NFMs) have been successfully prepared as novel solid desiccant materials. The NFM with LiCl content of 20% had a sorption capacity of 1.8 g g-1 at 25℃ and 95% RH (relative humidity), which was 4 times more than that of silica gels. The desorption isobars of the NFMs indicated that over...

In this study, the optimal magnitudes of silicon solar cell key parameters were calculated and verified using the PC1D simulation program. By varying the parameters such as emitter thickness, base thickness, emitter dopant density and base dopant density, the corresponding I–V curves were generated. According to open circuit voltage (Voc) and short...

A new polymer-based composite desiccant, Polyvinyl alcohol-LiCl nanofibrous membrane (PVA-LiCl NFM), has been prepared by the electrospinning technique. The newly-developed desiccant membrane not only has large moisture adsorption capacity, fast moisture adsorption rate and favorable stability, but also is featured by its low regeneration temperatu...

Electrospun PVA (polyvinyl alcohol)-LiCl composite membranes were prepared as novel solid desiccants. Experimental results show that nanofibrous membranes (NFMs) exhibit notable advantages in sorption capacity, sorption rate and low-temperature desorption rate, as compared with the solution-cast PVA-LiCl membranes (SCMs). The PVA NFM with 15 wt% Li...

In order to decrease the swelling of Nafion® and reduce the dependency of proton conductivity on high relative humidity (RH), mesoporous hollow silica spheres were synthesized and dispersed in Nafion matrix as micro-water-tanks in the proton exchange membranes (PEM). The morphologies of MHSi and Nafion/MHSi composite membranes are characterized by...

Ceramic-layer coated Lithium ion batteries (LIBs) separator shows excellent thermal stability, good electrolyte wettability, but usually poor mechanical strength. For the first time, Silica Encapsulated Nanofibrous Separator (SENS), in which ceramic coating layer is covalently bonded to the polymer nanofibers, is prepared as an advanced composite s...

A single lithium-ion polyelectrolyte composite membrane was designed and prepared. It consisted of lithiated Nafion®, propylene carbonate (PC) and mesoporous hollow silica spheres (MHSi). SEM and TEM analysis illustrated that the MHSi disperse uniformly in the membrane. The thermal stability of the composite membrane was tested using TGA which show...

Lithium ion phosphate (LiFePO4) nanocrystals are successfully in-situ grown on interconnected carbon nanotubes/mesoporous carbon nanosheets (designated as LFP@CNTs/CNSs) with a soft-templated method, which involves the multi-constituent co-assembly of a triblock copolymer, CNTs, resol and precursors of LFP followed by thermal treatment. X-ray diffr...

Poly(4-vinyl pyridine) nano-spheres (P4VP-NS) stabilized poly(vinyl phosphonic acid) (PVPA) membranes were prepared as proton conducting membranes for fuel cells. The acid–base interactions between P4VP-NS and PVPA were utilized to improve the dimensional and thermal stability of PVPA. In this work, the effects of acid–base interactions on proton c...

A novel and facile in situ soft-templated method is proposed for synthesizing a LFP/mesoporous carbon nanosheets (LFP/meso-CNSs) nanocomposite, which involves solvent evaporation induced self-assembly of triblock copolymers, with resol and inorganic salts as co-precursors of CNSs and LFP, followed by a heat treatment. The LFP/meso-CNSs nanocomposit...

Electrocatalytic reactions of glucose oxidation based on enzyme-labeled electrochemical biosensors demand a high enzymatic activity and fast electron transfer property to produce the amplified signal response. Through a "green" synthesis method, Pt@BSA nanocomposite was prepared as a biosensing interface for the first time. Herein we presented a co...

Dense poly(4-vinyl pyridine) (P4VP) brushes were grafted on the surface of silica nanoparticles (SiO2-NP) via surface-initiated atom transfer radical polymerization (ATRP). The "grafting from" method was discussed and the morphology, composition and structure of the P4VP-grafted SiO2 were characterized. Two different macroinitiators were synthesize...

An innovative and facile approach for preparing mesoporous silica membranes is described. The prepared membranes possess abundant, accessible, wormlike pores across the membrane. Narrow pore-size distribution and tunable pore sizes ranging from 2 to 6 nm have been obtained by using a sol–gel method with phosphoric acid as pore-forming agent. The pr...

An ultra-thin, free-standing proton-conductive membrane of Nafion®/Phosphosilicate/Nafion® (NPN) with a sandwich structure has been prepared. The NPN membrane of thickness 960 nm shows extremely low methanol permeability of 1 × 10−8 cm2 s−1, and area specific resistance (ASR) smaller than 0.2 Ω cm2.

An ultra-thin, flexible proton-conducting (PEI-PCGF)/phosphosilicate/(PEI-PCGF) (PPP) membrane with organic/inorganic multilayer structure is prepared. The total thickness of the membrane is ca. 500nm. In the multilayer structure, the brittle inorganic phosphosilicate layer was supported and protected by organic PEI-PCGF layers, which provide suffi...

A proton-conducting glass membrane based on porous phosphosilicate and perfluorosulfonic acid polymer was prepared via a modified sol–gel approach. The morphology, pore structure, water uptake property, proton conductivity and fuel cell performance of the membrane were investigated in this work. The hybrid glass membrane showed extremely high proto...

We report monolithic and transparent phosphosilicate membranes (PSMs) for high proton conduction. The membrane material was derived from the sol–gel precursors of tetraethoxysilane (TEOS) and orthophosphoric acid (H3PO4), which were subjected to hydrothermal treatment at 150 °C for 30 h. The obtained PSMs exhibited proton conductivities of up to 10...

Based on Nafion®/phosphosilicate (NPS) glass and sulfonated poly(ether ether ketone) (SPEEK) polymer, proton-conducting NPS/SPEEK composite membranes are prepared by a simple mechanical ball-milling approach. The chemical structure, morphology, pore structure, and proton conductivity of the NPS/SPEEK composite membranes are investigated. Due to the...

Soft magnetic composite particles of reduced iron coated with ultrathin films of poly(p-xylylene) (PPX) were prepared via chemical vapor deposition (CVD) polymerization. The structure, morphology, magnetic properties, and chemical stability of PPX encapsulated reduced iron particles were studied. It can be confirmed from FTIR spectrum that the poly...

The miscibility of poly(vinylphosphonic acid) (PVPA) and poly(ethylene oxide) (PEO) is studied for the first time in this work, and a miscibility diagram is obtained based on thermoanalytical (DSC) and optical microscopy data. On the basis of this knowledge, homogeneous PVPA/PEO blends are prepared as proton-conducting polymer films. The mobility o...

An ultra‐thin, flexible, free‐standing, proton‐conducting membrane of (PEI/PCGF)/SiO 2 /(PEI/PCGF) with a sandwich structure has been prepared. Giant membranes with areas up to about 16 cm ² and thicknesses of 600 nm have been obtained. The inorganic silica layer suppresses methanol permeation, while the two organic layers provide sufficient mechan...

The proton conductivities of poly(vinylbenzyl phosphonic acid) (PVBPA) homopolymer and its statistical copolymers with 4‐vinyl pyridine [poly(VBPA‐ stat ‐4VP)s] are comprehensively studied in this work. Temperature and composition‐dependent “dry” proton conductivities of the copolymers have been determined and the self‐condensation of phosphonic ac...

Most of the anhydrous proton conducting membranes are based on inorganic or partially inorganic materials, like SrCeO3 membranes or polybenzimidazole (PBI)/H3PO4 composite membranes. In present work, a new kind of anhydrous proton conducting membrane based on fully organic components of PBI and tridecyl phosphate (TP) was prepared. The interaction...

Copolymerization of diisopropyl-p-vinylbenzyl phosphonate (DIPVBP) and 4-vinylpyridine (4VP) by atom transfer radical polymerization (ATRP) was studied in the presence of different catalyst systems using DMF as solvent. When a CuIBr complex was used as catalyst and the reaction was carried at 90 °C in DMF, dramatically fast radical termination was...

Carbon nanotube (CNT)/Fe3O4 composites were prepared by depositing Fe3O4 onto CNTs. The morphologies, magnetic properties, sedimentation stability and magnetorheological properties of the composite particles were investigated by transmission electron microscopy, vibrating sample magnetometer, and a viscosimeter with magnetic equipment. The diameter...

Magnetorheological (MR) fluid is a novel material, of which the apparent viscosity and other rheological properties of the fluids can be controlled by the intensity of the magnetic field applied on the MR fluids. However, low sedimentation stability, due to the large difference of apparent density between soft magnetic particles and carriers in MR...

Magnetorheological (MR) fluids based on glycol, iron powder, polyvinylpyrrolidone (PVP), and carbon nanotubes (CNTs) were prepared. Effects of polyvinylpyrrolidone and carbon nanotubes on sedimentation stability and magnetorheological properties were studied. It is found that the synergetic effects of PVP and CNTs improve the sedimentation stabilit...

In present work, a kind of one-dimensional soft magnetic particles of carbon nanotubes (CNTs)/Fe3O4 composite was prepared. The effects of temperature, pH, and material composition on the formation of the magnetic composite particles are discussed. The experimental results show that these factors will influence the preparation of such kind of soft...

The soft magnetic composite of reduced iron particles encapsulated with polysiloxane shell was prepared by hydrolysis–condensation polymerization of tetraethylorthosilicate (TEOS) on the surface of iron particles. The structure, morphology, magnetic properties, and chemical stability of the polysiloxane coated iron particles were studied. The thick...

CNT (carbon nanotube)/Fe3O4 nanocomposites were prepared. The diameter of the CNT/Fe3O4 composites prepared was about 60 nm, while the diameter of the CNTs was about 20 nm according to the results of transmission electron microscopy (TEM) measurements. The average apparent density of the CNT/Fe3O4 nanoparticles was about 1.8 g cm−3, which is only a...