Electrolyte serves as the ion transport carrier and reactant supplier at electrolyte-electrode interfaces, and its formulation critically determines the performance of lithium-ion batteries (LIBs). It mainly comprises lithium salts, solvents and additives. In commercial LIB electrolytes, carbonate esters dominate with over 80 wt% content, and show high selectivity due to the high reactivity of carbon-involved chemical bonds. Apart from carbon-skeleton organic components, phosphorus-based compounds have long been applied in electrolytes, with lithium hexafluorophosphate (LiPF6) being the most classic lithium salt. Various phosphorus-containing components have been developed to optimize LIB performance. This work reviews phosphorus-containing electrolyte ingredients, categorizing them into lithium salts including LiPF6, lithium difluorophosphate (LiDFP) and lithium difluorobis(oxalato)phosphate (LiDFOP), and solvents/additives such as phosphate esters, phosphite esters and phosphazenes. These components effectively improve flame retardancy, low-temperature adaptability and high-voltage stability of LIBs. The review reveals the regulation mechanisms of phosphorus-containing components on LIB performance and provides theoretical support for their practical applications.
The development of efficient electrocatalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is essential for advancing metal-air batteries and related sustainable energy systems. In this work, we present a straightforward and eco-friendly approach to fabricate nitrogen-doped porous carbon shells encapsulating metal (M@NC), utilizing biomass-derived guanine as a green precursor for both carbon and nitrogen. A combined templating methodology is adopted, wherein tetraethyl orthosilicate (TEOS) serves as a rigid scaffold and polytetrafluoroethylene (PTFE) acts as an in-situ template-removing agent, thereby yielding a well-defined nanoporous architecture. Among the prepared catalysts, the optimized NiFe@NC composition demonstrates outstanding OER performance in 1.0 M KOH, achieving a low overpotential of 255 mV at 10 mA cm−2 along with remarkable stability over 70 h. In contrast, the Fe@NC variant exhibits superior ORR activity, featuring a high half-wave potential of 0.85 V and a nearly ideal four-electron reduction pathway. When employed as a hybrid air cathode (combining NiFe@NC and Fe@NC) in a rechargeable zinc-air battery, the assembled system delivers an open-circuit voltage of 1.48 V, a peak power density of 144.6 mW cm−2 and exceptional cycling stability, all of which significantly surpass the performance of a reference device using Pt/C + RuO2. These findings underscore the promise of biomass-derived precursors and a synergistic template strategy in crafting high-performance, cost-effective bifunctional electrocatalysts for energy storage and conversion applications.
Controlling the balance between cobalt (Co) dissolution and surface passivation is essential for chemical mechanical polishing (CMP) of Co interconnects, yet the interfacial role of organic ligands can vary with both solution chemistry and substrate crystallography. Here, the effects of the oxidizing environment and crystallographic orientation on tartrate acid (TA) - Co interfacial reactions were investigated in alkaline solutions relevant to Co CMP. Potentiodynamic polarization measurements showed that TA produced opposite electrochemical responses depending on the presence of H2O2. In H2O2-containing solutions, increasing the TA concentration increased the corrosion current density and Co dissolution, indicating that complexation-assisted dissolution became the dominant interfacial pathway. X-ray photoelectron spectroscopy further revealed a decrease in CoO and relative increase in the Co3O4-like (or mixed-valence) component, consistent with repeated oxide dissolution, exposure of fresh Co, and subsequent reoxidation. In the absence of H2O2, TA decreased the corrosion current density by several orders of magnitude and reduced dissolved Co from 2.76 to 0.01 μg/L. This behavior was attributed to the formation of a surface-associated Co(II)-TA-containing passive layer that inhibited further Co dissolution. X-ray diffraction and electron backscatter diffraction analyses further indicated that the oxidation and dissolution reactions were crystallographically nonuniform, with non-basal orientations showing a higher oxidation tendency than the (0001) basal orientation. These results demonstrate that the oxidizing environment determines the dominant interfacial pathway of TA, while crystallographic orientation modulates its local manifestation on polycrystalline Co, providing an electrochemical basis for controlling dissolution and passivation in Co CMP.
The development of reliable and cost-effective analytical methods for the enantioselective determination of chiral drugs remains a critical challenge in pharmaceutical and clinical analysis. Herein, we report a novel voltammetric chiral sensor based on a glutathione–graphene oxide (GO-Glut) hybrid material, fabricated via copper-catalyzed azide–alkyne cycloaddition (CuAAC) click chemistry for atenolol (Atn) enantiorecognition. Covalent functionalization of GO with the propargyl derivative of glutathione (PropGlut) was confirmed by FTIR, XPS, and SEM analyses. The modified electrode (GCE/GO-Glut) exhibits excellent electrochemical properties: the charge transfer resistance (0.79 kΩ) is even lower than that of the bare glassy carbon electrode, and the electroactive surface area is significantly restored compared to non-functionalized GO. Density functional theory (DFT) calculations revealed that R-Atn forms two additional hydrogen bonds with the glutathione selector, resulting in an 8.33 kJ/mol higher interaction energy than that of S-Atn. Kinetic studies further demonstrate that the rate-determining step differs between the two enantiomers: the electrode process is adsorption-controlled for R-Atn but diffusion-controlled for S-Atn. This theoretical and kinetic insight is fully reflected in the experimental voltammetric response: the GCE/GO-Glut sensor discriminates R- and S-Atn with a peak potential difference (ΔEpS-R) of 40 mV and an enantioselectivity coefficient (ipR/ipS) of 2.0. The sensor provides a linear response for both enantiomers in the ranges 50–150 μM and 150–1000 μM, with detection limits of 0.6 μM (R-Atn) and 1.0 μM (S-Atn). Moreover, the sensor enables quantitative determination of the enantiomeric composition in mixtures, as demonstrated by the linear dependence of both peak current and peak potential on the mass fraction of S-Atn. Most importantly, the method was successfully applied to the determination of atenolol enantiomers in human urine without any elaborate sample pretreatment. Spike-recovery tests gave recoveries of 96.1–98.8% with RSD values below 2%, confirming the accuracy and reliability of the sensor in a complex biological matrix. The developed GCE/GO-Glut sensor offers a straightforward, rapid, and economical platform for enantioselective voltammetric analysis of atenolol, with great potential for quality control and therapeutic monitoring.
