ChemElectroChem最新文献

Due to its high electrical conductivity and large specific surface area, graphene is a highly promising material for electrochemical energy storage applications. However, its practical use remains limited due to stability issues, primarily due to π–π stacking interactions between the graphene sheets. Herein, a graphene-based composite is reported that overcomes this limitation. This composite consists of reduced graphene oxide (rGO) decorated with polyoxometalate (POM) nanoclusters, [SiW₁₂O₄₀]⁴⁻. To obtain this composite, first, [SiW₁₂O₄₀]⁴⁻ ions are electrochemically reduced, then the solution is mixed with a suspension of graphene oxide (GO). The reduced POMs reduce GO and deposit on the graphene sheets, leading to a rGO@POM composite. The composite suspension could be drop casted onto an electrode without requiring binders. The interest of [SiW₁₂O₄₀]⁴⁻ is its reversible redox properties with the potentials in cathodic domain allowing to explore an unusual potential domain (1.6 V) in an aqueous electrolyte (Na₂SO₄/H₂SO₄, pH 4). This approach afforded a pseudocapacitive material with excellent stability, showing no capacitance loss over 20,000 cycles at 1 V•s⁻¹. Furthermore, the synergistic effect between the faradaic contributions due to [SiW₁₂O₄₀]⁴⁻ and the rGO capacitive behavior results in a high volumetric capacitance exceeding 300 F cm⁻³ and an outstanding energy density of 26 mWh cm⁻³.

Polymeric electrochromic devices (ECDs) can be used in a wide range of applications like smart windows or displays. For ideal electrochromic performance and stability, the charge balancing in these devices is crucial. In this study, roll-to-roll slot-die coating is used to prepare three film thicknesses of the in situ polymerized sidechain-modified poly(3,4-ethylenedioxythiophene) derivative PEDOT-EthC6 on indium tin oxide coated polyethylene terephthalate, ranging from approx. 100 nm to 170 nm. The PEDOT-EthC6 electrodes show transmittance modulations varying from τ_v = 31% ↔ 78% to τ_v = 13% ↔ 68%. Constant current constant voltage measurements reveal that the volumetric charge density increases with film thickness from 0.15 C cm⁻³ to 0.18 C cm⁻³. The three films are used in hybrid ECDs with Ni oxide as the counter electrode, where the PEDOT-EthC6 electrode is either under-dimensioned, matching, or over-dimensioned. The latter shows the largest transmittance modulation of τ_v = 12% ↔ 55%. Using three-electrode cells, it is found that the over-dimensioned PEDOT-EthC6 electrode limits the potential range of this electrode, preventing side reactions. Simultaneously, the potential window is widened at the Ni-oxide electrode, enabling it to be fully switched. The ECD shows good cycling stability over 5000 cycles at 25 °C and 65 °C.

This review showcases crucial factors in mechanisms of electrochemical CO₂ reduction by taking Pd-based electrocatalysts (mainly, monometallic Pd and Pd-based alloy nanoparticles) as examples. There are dependencies of experimental conditions (e.g., applied potentials) and constituent elements of the electrocatalysts on the reduction products of electrochemical CO₂ reduction. Moreover, Pd-based electrocatalysts have unique characteristics in electrochemical CO₂ reduction: alteration in selectivities for CO and HCOOH formations by applied potentials, almost no overpotential for HCOOH formation, deactivation of their electrocatalyses by poisoning with CO formed through CO₂ reduction, and in situ formation of palladium hydride. Here, we survey the characteristics of Pd-based electrocatalysts in terms of experimental and theoretical insights. Then, it is described that formation energies of intermediates estimated by density functional theory calculations are understandable factors to explain experimental performances of Pd-based electrocatalysts. Considering the estimated factors, this review exhibits a perspective of utilization of the factors to advance the research activity of electrochemical CO₂ reduction to its new horizon by using data science and high-throughput experiments.

Aromatic nitriles are extensively produced chemicals with a wide variety of applications. The high demand of these compounds justifies the search for sustainable synthesis alternatives using renewable energy. Here, an electrochemical oxidation of toluene and xylene derivatives to aromatic nitriles using NH₃ and H₂O under ambient conditions in a one-pot, two-step protocol is reported. In a first step, the toluene derivative is oxidized in the absence of a catalyst to the aldehyde. In the second step, ammonia is added together with LiI as an electrocatalyst to obtain the nitrile. The reaction network and mechanism are investigated using control experiments and cyclic voltammetry.

This study introduces a novel quasi-solid-state battery system as a proof of concept. A 55-nm solid-state electrolyte layer of lithium phosphorous oxynitride (LiPON) is deposited on slurry-based graphite electrodes and assembled against lithium metal to evaluate interfacial compatibility and electrochemical performance under controlled conditions. In contrast to thin-film quasi-solid-state batteries, this approach leverages a realistic electrode architecture, where LiPON adjusts to the rough surface of the slurry-cast graphite. By utilizing LiPON's dual functionality as both a solid-state electrolyte and a separator, the system eliminates the need for a conventional separator, while requiring only 5–10% of the liquid electrolyte used in equivalent systems. This design significantly reduces internal resistance and prevents contact loss during cyclic volume changes. Electrochemical analyses, including cyclic voltammetry, galvanostatic cycling, and impedance spectroscopy, demonstrate lithium intercalation stages consistent with those in liquid electrolyte-based systems, stable cycling behavior at room temperature and reduced electrode impedance of a few 10 Ω cm². Furthermore, X-ray photoelectron spectroscopy and scanning transmission electron microscopy confirm the formation of a solid–liquid electrolyte interface and the structural integrity of LiPON, which enhances charge transfer and long-term stability. These findings highlight the potential of quasi-solid-state batteries for safer, more compact, and cost-effective energy storage solutions.

This cover artwork illustrates the development of emerging materials such as MOFs, 2D materials, SACs, HEAs, perovskites, and MXenes as highly efficient electrocatalysts for water splitting. It highlights the advances in synthesis and heterostructural engineering for judicious synchronization of the synthesis strategies with the emerging electrocatalysts for exploring the potentials and challenges of the next generation of high-performing advanced electrocatalysts for sustainable hydrogen production. Further information can be found in the Research Article by Thangjam Ibomcha Singh, Seunghyun Lee, and co-workers (DOI: 10.1002/celc.202500014).

This study presents the synthesis of biomass-derived carbon-metal organic framework (C-MOF) using modified sawdust as a sustainable precursor and elucidates its electrochemical performance as an anode material for sodium-ion batteries (SIBs). Optimization at a pyrolysis temperature of 1000 °C with 7.5% catalyst concentration, C-MOF achieves a high surface area of 312 m⁻²g⁻¹ and electrical conductivity of 28 S cm⁻¹, contributing to its long cycling electrochemical performance compared to commercial hard carbon (HC). The C-MOF delivers a maximum discharge capacity of 348.5 mAh g⁻¹ at 25 mA g⁻¹ and exhibits an outstanding cycling stability over 600 cycles with minimal degradation. Electrochemical techniques (cyclic voltammetry, impedance, and galvanostatic charge–discharge) reveal efficient sodium-ion intercalation and favorable ion diffusion characteristics within the porous C-MOF structure. These findings position C-MOF as a promising, sustainable, and long-standing anode material for advanced SIB applications, offering enhanced rate capability, durability, and effective sodium-ion kinetics.

The synthesis of peptide-based linkers for antibody-drug conjugates involves an oxidative decarboxylation step. Traditional Hofer–Moest electrolysis conditions are not suitable to achieve this transformation due to the presence of an oxidatively labile Fmoc-protecting group. Herein, a solvent-enabled electrochemical procedure has been established, whereby the solvent electrochemical window prevents degradation of the protecting group. The method has been demonstrated for several relevant peptides in good to very good yields (64–92%).

Physical and chemical parameters, such as temperature, water/hydrogen/oxygen partial pressures, are distributed inhomogeneous inside a polymer electrolyte fuel cell during the operation and have a large influence on its performance and durability. In this study, the oxygen partial pressure (p(O₂)) is visualized in real-time/space using an oxygen-sensitive dye on the surface of the gas diffusion layer (GDL) during power generation at temperatures of 80, 100, and 110 °C using a 20 mm × 20 mm single cell with ten straight gas flow channels. p(O₂) on the surface of the GDL is visualized for the first time at temperatures higher than 100 °C, desired especially for heavy-duty vehicle application, due to advantages such as less susceptibility to catalyst poisoning and the option to use smaller and lighter radiators. The oxygen partial pressure on the surface of the GDLs is monitored to be higher than the values expected from a simple model and decreased only slightly along the gas flow channel with increasing current densities. The work shows that high p(O₂) on the surface of the GDL is due to the short gas flow channels and accumulating water/vapor inside the GDL and the catalyst layer limiting the gas diffusion.

Lithium–sulfur batteries have attracted great research interest due to the high theoretical capacity of sulfur of 1672 mAh g⁻¹. However, they have various problems due to the shuttle current caused by molecular sulfur dissolving in the electrolyte. Hence, electrolyte design is a key focus when optimizing the batteries. This study investigates the relationship between cycling data and electrochemical properties measured with cyclovoltammetric measurements, shuttle current measurements, and impedance spectroscopy. Using the acquired data, a partial least squares model to screen solvent candidates in reference to these findings is introduced. This model is based on cycling data as well as density functional theory-calculated Conductor-like Screening Model for Real Solvents data of the solvents and (solvated) lithium–polysulfides. The usefulness of the converged method is demonstrated by using it to identify new possible electrolyte systems. A subset of ten selected electrolyte systems is evaluated experimentally and their performance is reported. One of those electrolytes, 1.4 M LiTFSI, in pimelonitrile solution and without any further additives, displays exceptional cycling stability already on the first attempt, reaching a state of health of 50% after 115 cycles and maintaining a Coulombic efficiency of close to 100% during the entire cycling procedure.