State of Charge Dependency of Graphitized-Carbon-Based Reactions in a Lithium-ion Secondary Cell Studied by Electrochemical Impedance Spectroscopy

Scaling behavior of iron in capacitive deionization (CDI) system

This study investigated the fouling and scaling behaviors in a capacitive deionization (CDI) system in the presence of iron and natural organic matter (NOM). It was found that the salt adsorption capacity (SAC) significantly decreased when treating Fe-containing brackish water, with higher Fe concentrations leading to severer SAC reduction. Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) analysis demonstrated that Fe₂O₃ appeared to be the predominant foulant attached on the electrode surface, which was difficult to be removed via backwashing, indicating the irreversible property of the foulant. Further characterizations (e.g., N₂ sorption-desorption isotherms, electrochemical impedance spectroscopy and cyclic voltammetry) revealed that the CDI electrodes suffered from obvious deterioration such as specific surface area loss, resistance increase and capacitance decline with the occurrence of Fe scaling. While the presence of NOM alleviated the Fe scaling through NOM-Fe complexing effects, NOM itself was found to have negative impacts on CDI desalination performance due to their strong interactions with the carbon electrodes.

Critical Review of the Use of Reference Electrodes in Li-Ion Batteries: A Diagnostic Perspective

Use of a reference electrode (RE) in Li-ion batteries (LIBs) aims to enable quantitative evaluation of various electrochemical aspects of operation such as: (i) the distinct contribution of each cell component to the overall battery performance, (ii) correct interpretation of current and voltage data with respect to the components, and (iii) the study of reaction mechanisms of individual electrodes. However, care needs to be taken to ensure the presence of the RE does not perturb the normal operation of the cell. Furthermore, if not properly controlled, geometrical and chemical features of the RE can have a significant influence on the measured response. Here, we present a comprehensive review of the range of RE types and configurations reported in the literature, with a focus on critical aspects such as electrochemical methods of analysis, cell geometry, and chemical composition of the RE and influence of the electrolyte. Some of the more controversial issues reported in the literature are highlighted and the benefits and drawbacks of the use of REs as an in situ diagnostic tool in LIBs are discussed.

Synergistic lithium storage of a multi-component Co2SnO4/Co3O4/Al2O3/C composite from a single-source precursor

Co₂SnO₄/Co₃O₄/Al₂O₃/C composite is prepared from a laurate anion-intercalated CoAlSn-layered double hydroxide single-source precursor, and delivers highly enhanced electrochemical performances.