Electrochemical science advances最新文献

The rapid adoption of electric vehicles (EVs) has intensified the focus on lithium-ion battery (LIB) fire safety, particularly the risks posed by thermal runaway (TR). This study evaluates the performance of a novel foam-based fire extinguishing agent under two distinct application protocols: Protocol 1, employing intermittent short-duration sprays, and Protocol 2, involving an initial prolonged spray followed by intermittent applications. Within the two tested configuration–protocol pairs, the intermittent-spray protocol achieved 2.75 times greater extinguishing efficiency than the prolonged-spray protocol, while conserving resources and providing sustained cooling. Soft-pack LIBs, with their layered structure, facilitated deeper foam penetration, resulting in faster cooling (2.8°C/s) and effective smoke suppression. In contrast, hard-shell LIBs, characterized by their rigid design, exhibited slower cooling (1.10°C/s) and prolonged smoke dissipation due to limited foam diffusion. These findings emphasize the importance of tailoring suppression strategies to battery design and highlight the superior performance of intermittent foam application. This work provides a framework for optimizing fire safety protocols in large LIB storage systems with freely accessible battery packs and offers configuration-specific insights rather than a full protocol ranking.

Direct formate fuel cells (DFFCs) provide a safe liquid-fuel pathway for renewable energy storage, yet achieving high performance under alkali-free conditions remains challenging due to limitations in ion transport and catalyst-layer structure. Here, for the first time, a cation-exchange membrane (CEM) was combined with cationic ionomers (CI) in both catalyst layers to establish a fully alkali-free configuration, and the effects of ionomer loading were systematically examined. Optimizing the anode ionomer content to ionomer-to-carbon (I/C) ratio of 0.83 produced a well-balanced liquid–catalyst–ionomer triple-phase boundary and improved reaction kinetics. Fuel-composition analysis revealed that Na⁺ transport across the CEM accounted for only 20%–30% of the theoretical value, indicating that proton transport dominates charge compensation under alkali-free operation. At the cathode, reducing CI content enhanced oxygen transport by thinning the ionomer film and increasing access to catalytic sites, achieving a peak power density of 92 mW·cm⁻²—over twice that of previously reported alkali-free Na-ion-conducting DFFCs. Although lower ionomer loading increased HCOO⁻ crossover and accelerated voltage decay, these results demonstrate that appropriate CI tuning in both electrodes effectively balances oxygen transport, crossover and ion conduction, thereby enabling substantially improved performance in alkali-free DFFCs without external alkali additives.

The transport of hydrogen for the import of renewable energy will play an important role for the highly industrialized regions in Europe to meet their energy needs. As the storage and transportation of neat hydrogen comes with considerable downsides with respect to energy density and infrastructure compatibility, chemical hydrogen carriers are a promising concept to enable large-scale hydrogen import. This perspective discusses the advantages, limitations and current technology readiness levels of chemical hydrogen carriers for intercontinental transport by ship. In terms of rapid scale-up and market entry, ammonia and methanol are the most promising short-term options. If the market for chemical hydrogen carriers grows as expected, it is likely that chemical hydrogen carriers optimized for certain applications will coexist, optimizing the individual value chains.

Urea is formed from the metabolism of proteins and used as a biomarker for diagnosing and monitoring various medical conditions. In this work, a urea biosensor based on an electrolyte-insulator-semiconductor capacitor (EISCAP) modified with a stacked polyelectrolyte polyallylamine hydrochloride (PAH)/urease bilayer prepared by the layer-by-layer (LbL) technique is presented for the first time. The LbL formation of the PAH/urease bilayer was monitored with an underlying charge-sensitive Al/p-Si/SiO₂/Ta₂O₅ EISCAP using convenient capacitive-voltage and constant-capacitance mode measurements. Urea-sensitive EISCAP biosensors were electrochemically characterised in buffer solutions and artificial urine (AU) samples spiked with various concentrations of urea between 0.1 mM and 50 mM. The biosensors exhibited urea sensitivities of ca. 35.4 mV/dec and 32.1 mV/dec in buffer and AU solutions, respectively. Finally, local surface pH changes as a function of urea concentration have been evaluated. The obtained findings demonstrate the potential of PAH/urease-modified EISCAPs for non-invasive urea biomarker detection in urine samples at homecare or in-field settings.

The energy storage performance of supercapacitors—defined by specific capacitance, energy density, and power density—is strongly influenced by the structural and electrochemical properties of electrode materials. While cathode development has advanced significantly, research on efficient and sustainable anode materials remains limited, hindering further improvements in energy density. This study presents a low-cost, sustainable anode material derived from Abelmoschus esculentus (AE) seed biomass. Activated carbon (AE-AC) was prepared via chemical activation and subsequently coated with magnetic Fe₃O₄ nanoparticles synthesised through co-precipitation to form an AE-AC-doped Fe₃O₄ nanocomposite. The materials were characterised using XRD, SEM–EDX, BET surface area analysis, and other techniques. Electrochemical performance was evaluated using cyclic voltammetry (CV), galvanostatic charge/discharge (GCD), and electrochemical impedance spectroscopy (EIS). At a scan rate of 2.5 mV/s, both electrodes exhibited peak capacitance. GCD analysis showed specific capacitances of 119.97 F/g for AE-AC and 205.86 F/g for AE-AC-doped Fe₃O₄ at 0.05 A/g. EIS results confirmed enhanced performance of the nanocomposite in acidic medium. These findings highlight the potential of AE-based activated carbon composites as environmentally friendly and efficient anode materials for next-generation supercapacitors.

Anion exchange membrane (AEM) electrolysis is one of the most promising water electrolysis technologies, combining the advantages of proton exchange membrane (PEM) electrolysis, such as high gas purity, high current densities and dynamic operation, while using cheap transition metal electrocatalysts known from alkaline water electrolysis (AWE). AEM water electrolysis (AEMWE), when operated liquid (electrolyte or water) free (dry) at the cathode side, offers simplified water management, reducing the balance-of-plant. Numerous factors, such as cell design, membrane properties, flow rate of electrolyte and operation parameters, directly or indirectly, impact the performance of AEMWE, which becomes even more vital when the cathode compartment is operated liquid free. Herein, this work presents a comprehensive overview of several factors involved in the performance of a dry cathode AEMWE. Advancements and challenges in membrane materials, asymmetric electrolyte feeds and operating parameters were analysed. Finally, to have a durable and efficient AEMWE, this article discusses current development on the dry cathode AEMWE technology and outlines prospective avenues for further improving the system.

Dopamine (DA) plays a vital role as a neurotransmitter in the central nervous system (CNS), and its accurate quantification is essential for diagnosing neurological disorders. However, selective and sensitive detection of DA in complex biological matrices remains a challenge due to interference from coexisting biomolecules. In this study, a platinum nanoparticle-decorated carbon nanotubes/polypyrrole-carbon (Pt@CNTs/PPy-C) nanocomposite was synthesized via a facile two-step process involving ultrasonication and photo-reduction, eliminating the need for stabilizers or dispersants. Structural and morphological analysis confirmed the uniform distribution of Pt nanoparticles within the CNTs/PPy-C matrix, enhancing electrocatalytic activity. Electrochemical kinetic studies revealed that DA electro-oxidation on the nanocomposite-modified glassy carbon electrode (GCE) follows adsorption-controlled kinetics, with a transfer coefficient (α) of 0.51 and a heterogeneous rate constant of 8.37 s⁻¹. Differential pulse voltammetry (DPV) demonstrated a high sensitivity of 3.45 µA µM⁻¹ cm⁻² over a linear range of 2.0–24.0 µM with a detection limit of 0.034 µM. The sensor exhibited outstanding selectivity for DA in the presence of various interfering species, along with excellent reproducibility, repeatability and stability. Additionally, the sensor demonstrated high accuracy and reliability in detecting DA in a commercial pharmaceutical formulation, with recovery rates ranging from 96.72% to 101.40%. These findings highlight the potential of the Pt@CNTs/PPy-C nanocomposite as a promising electrocatalyst for DA detection, contributing to the development of highly efficient electrochemical sensors for biomedical and pharmaceutical applications.

The conventional electrolytes for Li-ion batteries are based on the $�{\mathrm{LiPF}}_6$ salt and carbonate solvents. Due to challenges with the stability, alternative salts are sought, and lithium bis(fluorosulfonyl)imide (LiFSI) is an interesting candidate. In this work, we investigate the performance of concentrated electrolytes based on LiFSI (range 1–10 M) and carbonate solvents, in combination with low-cost, micron-sized silicon anodes. LiFSI has an excellent solubility, and by use of concentrated electrolytes, corrosion of the aluminium current collector on the cathode side can be avoided, which is otherwise a challenge. The 5 M LiFSI electrolyte (molar salt to solvent ratio of 1:2.5) shows a similar ohmic resistance and rate performance as the 1 M LiFSI electrolyte. The solid electrolyte interphase formed in 5 M LiFSI is thin and dominated by inorganic compounds, in particular LiF. For long-term galvanostatic cycling with a lower cut-off potential of 50 mV, the 1 M LiFSI electrolyte shows the best stability. However, by limiting the lithiation, and thus the expansion of the silicon by increasing the cut-off voltage to 120 mV, the cycling performance is similar for all electrolytes and electrodes deliver $�>$ 1000 mAh/g for more than 300 cycles.

The ability of organic electrochemical transistor–based biosensor to distinguish between salt stress tolerances of two different succulent species, Cactaceae and Euphorbia Milii, has been demonstrated. Channel current modulation at the transistor's output has been established as the sensing tool. An equivalent electric circuit model for the in vivo biosensor device has been derived with the help of electrochemical impedance spectroscopy technique.