Anion exchange membrane water electrolysis (AEMWE) offers the ambition of combining the advantages of alkaline electrolysers, i.e. the use of cheap and plentiful catalytic materials, with those of proton exchange membrane electrolysis of water, i.e. high performance and fast response to changing operating conditions. However, the development of performing and durable anion exchange membranes is still the major challenge for the ultimate industrial adoption of AEMWE. Here, we introduce an innovative nanocomposite AEM based on trimethylammonium functionalized silica nanoscale ionic materials (NIM-N+) incorporated in quaternized polysulfone (qPSU). The presence of NIM-N+ in the hydrophilic clusters of qPSU produces a remarkable enhancement in the dimensional and thermo-mechanical stability of the composite AEM. Furthermore, Nuclear Magnetic Resonance (NMR) and Electrochemical Impedance Spectroscopy (EIS) investigations highlighted that the nanoparticles are directly involved in the transport process of hydroxide ions. This enabled qPSU/NIM-N+ composite membrane to achieve impressive anionic conductivity values, e.g. about 110 mS cm-1 at 80 degrees C and 95% relative humidity (RH). The AEMWE single cell, equipped with this membrane, operated properly both with 1 or 0.5 M KOH solution, displaying a current density larger than 3.5 A cm-2 at 2.2 V and 80 degrees C.

'Green' hydrogen production using anion exchange membrane (AEM) water electrolysis is one of the most promising approaches to address the severe energy crisis facing human society. However, to enable commercially viable hydrogen generation, huge improvement in the AEM technology is imperative, including membrane stability, higher operating temperature, ion conductivity, power performance, and cost reduction. Herein, a novel anion conductive membrane for water electrolysis is synthesized using low-cost and eco-friendly polysulfone as the base polymer, while chemical grafting of quaternary ammonium functionalities has been exploited to confer anion conductive properties. The physico-chemical features, the mechanical properties, and the electrochemical performance were widely investigated by a combination of various techniques including DMA, pulsed field gradient nuclear magnetic resonance spectroscopy, electrochemical impedance spectroscopy, and linear sweep voltam-metry in an electrolysis cell. The quaternary-ammonium-modified polysulfone (qPSU) membrane exhibited impressive hydrolytic and mechanical stabilities as a result of a nanophase segregation be-tween hydrophilic/hydrophobic domains in such electrolytes. The latter feature enables the formation of wide percolating ion clusters in the qPSU AEM, which form a highly interconnected pathway for efficient hydroxide conduction. Water electrolysis single cells equipped with this membrane reached the remarkable current density of 4.2 A/cm2 at 2.2 V and 90 degrees C.(c) 2022 Elsevier Ltd. All rights reserved.

Autonomic self-healing (SH), namely, the ability to repair damages from mechanical stress spontaneously, is polarizing attention in the field of new-generation electrochemical devices. This property is highly attractive to enhance the durability of rechargeable Li-ion batteries (LIBs) or Na-ion batteries (SIBs), where high-performing anode active materials (silicon, phosphorus, etc.) are strongly affected by volume expansion and phase changes upon ion insertion. Here, we applied a SH strategy, based on the dynamic quadruple hydrogen bonding, to nanosized black phosphorus (BP) anodes for Na-ion cells. The goal is to overcome drastic capacity decay and short lifetime, resulting from mechanical damages induced by the volumetric expansion/contraction upon sodiation/desodiation. Specifically, we developed novel ureidopyrimidinone (UPy)-telechelic systems and related blends with poly(ethylene oxide) as novel and green binders alternative to the more conventional ones, such as polyacrylic acid and carboxymethylcellulose, which are typically used in SIBs. BP anodes show impressively improved (more than 6 times) capacity retention when employing the new SH polymeric blend. In particular, the SH electrode still works at a current density higher than 3.5 A g-1, whereas the standard BP electrode exhibits very poor performances already at current densities lower than 0.5 A g-1. This is the result of better adhesion, buffering properties, and spontaneous damage reparation.

Blended electrolyte membranes based on sulfonated Polyethersulfone (sPES) and sulfonated Poly(ether ether ketone) (sPEEK) were prepared in two different ratios (i.e. 50/50 and 25/75) via a simple, scalable and inexpensive solution casting process to investigate their suitability for direct methanol fuel cell (DMFC) applications. Thermo-mechanical analysis revealed higher flexibility and thermal resistance with the blending of these two macromolecules, without any evidence of phase-segregation, and with good chemical stability. Furthermore, the proton transport was facilitated while the methanol permeability was dramatically reduced. The DMFC tests confirmed outstanding performance by using the membrane with the blend ratio 25/75, reaching a power density of about 130 mW cm(-2) at 80 degrees C in 4 M methanol solution. These features and the cost-effectiveness of sPES-SPEEK membranes make them interesting candidates for use in next-generation DMFCs. (c) 2020 Elsevier Ltd. All rights reserved.

High performing and cost effective nanocomposite membranes for DMFC application are synthesized by incorporating hygroscopic layered double hydroxides (LDH) particles into sulfonated polysulfone (sPSU). A significant improvement in the dimensional stability as well as in the water and methanol molecular dynamics of the sPSU_LDH composite membrane is observed in comparison with both pristine sPSU and Nafion 212. The strong electrostatic interaction occurring between positively charged LDH platelets and negatively charged polymer chains of sPSU alters the microstructure of the ionic domains, allowing an effective reduction of the methanol permeability whilst improving the proton conductivity. The methanol crossover measurements confirmed that sPSU_LDH membranes are able to withstand high methanol concentration without significant aftermath on the chemical stability of the electrolyte. The features enable the single DMFC assembled with the sPSU_LDH nanocomposite to achieve the remarkable power density of 150 mW cm(-2) at 80 degrees C in 5 M methanol solution. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Poly(ε-caprolactone) (PCL) is a cheap and sustainable polymer with long-term degradation (3–4 years) and low temperature transition (Tm=∼60°C). We report on the investigation of PCL as a valid green candidate for Carbon Capture and Utilization (CCU). Studies were carried out by two complementary tools: a Sievert-type volumetric apparatus, to thoroughly analyse the CO2 adsorption/desorption process inside the polymer, and Nuclear Magnetic Resonance (NMR) spectroscopy for a deeper study of the molecular dynamics and confinement effects through 13C – pulsed field gradient (PFG) method (self-diffusion measurements), relaxation times (T1) and spectral analysis. The morphology of the solid-state PCL was also investigated by Scanning Electron Microscopy (SEM). The effects of both the physical state and the adsorption process conditions on the PCL's CO2 sorption capabilities were investigated as well as those concerning the cyclic life and the regeneration process. We find that two kind of adsorption sites are present in PCL matrix. Furthermore, PCL show a remarkable and complete thermoreversibility of the CO2 adsorption process, a key condition in view of possible applications in this field.

Composite membranes based on Nafion with the inclusion of cationic and anionic nanoclays, Laponite, and layered double hydroxide (LDH), respectively, were used to increase the operating temperature of a direct methanol fuel cell (DMFC). The electrochemical behavior of the hybrid nanocomposites was investigated in a single cell at different temperatures (from 90 to 110 °C), and the results were compared with those obtained on the filler-free Nafion membrane. Cell resistance measurements showed a significant improvement of the water retention capability at intermediate temperature for the composite membranes, in particular the LDH-based one. This feature was investigated and explained by a thorough NMR study (diffusometry, relaxometry, and 1H spectral analysis) on the different membranes. Furthermore, the dispersion of 2D plate-like nanolayers in the polymeric matrix demonstrates to be a physical barrier, considerably reducing the methanol mobility through an increase of the tortuosity of the diffusional paths of methanol molecules.

Graphene oxide (GO) is well known as an excellent amphiphilic material due to its oxygen-containing functional groups and its chemical tunability. By intercalation chemistry, organo-modified GO containing sulfonilic terminal groups were prepared and used as nanoadditive in Nafion polymer for the creation of hybrid exfoliated composites. The incorporation of hydrophilic 2D platelike layers in the Nafion membranes is expected to induce advantages in terms of thermal stability and mechanical and barrier properties (limitation of the methanol crossover by increased tortuosity and obstruction effect), although it may negatively affect the proton conductivity. In this work, we show how different preparation methods of the nanocomposites influence morphology, transport properties, and barrier effect to methanol. The hybrid membranes are characterized by powder X-ray diffraction and microscopies (SEM, TEM, and AFM). Water and methanol transport properties inside the nanocomposites are investigated by NMR spectroscopy (diffusivity and relaxation times), unveiling a reduction of the methanol diffusion and, nevertheless, an increase in the proton mobility and water retention at high temperatures. Finally, the electrochemical properties are investigated by direct methanol fuel cell (DMFC) tests, showing a significant reduction of the ohmic losses at high temperatures, extending in this way the operating range of a DMFC.