Reversibility of disulphide formation and breakage on l-cysteine examined through vibrational modes using in situ Raman spectroscopy.

LiFePO 4 electrodes, composed of 5% PVDF and 5% carbon, were coated on aluminum foil. The LiFePO 4 electrodes were calendered to 2.5 g cm −3 . A comparison of the electrochemical performance of uncalendered and calendered LiFePO 4 electrodes was made. Electrochemical impedance spectroscopy analysis of LiFePO 4 symmetric cells and analysis of four-point probe resistance measurements showed that calendering of the electrodes resulted in a large decrease in contact resistance at the current collector -electrode interface. Rate capability data of Li/LiFePO 4 coin cells showed that calendered electrodes maintained their capacity better than uncalendered electrodes at high rates. The contact resistance, made up of constriction resistance and film resistance, was analyzed with contact theory for plastic deformation.

Black phosphorus (BP) is a promising anode material in lithium‐ion batteries (LIBs) owing to its high electrical conductivity and capacity. However, the huge volume change of BP during cycling induces rapid capacity fading. In addition, the unclear electrochemical mechanism of BP hinders the development of rational designs and preparation of high‐performance BP‐based anodes. Here, a high‐performance nanostructured BP–graphite–carbon nanotubes composite (BP/G/CNTs) synthesized using ball‐milling method is reported. The BP/G/CNTs anode delivers a high initial capacity of 1375 mA h g−1 at 0.15 A g−1 and maintains 1031.7 mA h g−1 after 450 cycles. Excellent high‐rate performance is demonstrated with a capacity of 508.1 mA h g−1 after 3000 cycles at 2 A g−1. Moreover, for the first time, direct evidence is provided experimentally to present the electrochemical mechanism of BP anodes with three‐step lithiation and delithiation using ex situ X‐ray diffraction (XRD), ex situ X‐ray absorption spectroscopy (XAS), ex situ X‐ray emission spectroscopy, operando XRD, and operando XAS, which reveal the formation of Li3P7, LiP, and Li3P. Furthermore, the study indicates an open‐circuit relaxation effect of the electrode with ex situ and operando XAS analyses.

Chemiresistive sensors based on graphene-like carbon films are very stable and sensitive. They can be used for continuous online monitoring of free chlorine.

Aluminum foil is the predominant cathodic current collector in lithium-based batteries due to the high electronic conductivity, stable chemical/electrochemical properties, low density, and low cost. However, with the development of next-generation lithium batteries, Al current collectors face new challenges, such as the requirement of increased chemical stability at high voltage, long-cycle-life batteries with different electrolyte systems, as well as improved electronic conductivity and adhesion for new electrode materials. In this study, we demonstrate a novel graphene-like carbon (GLC) coating on the Al foil in lithium-based batteries. Various physical and electrochemical characterizations are conducted to reveal the electronic conductivity and electrochemical stability of the GLC-Al foil in both carbonate- and ether-based electrolytes. Full-cell tests, including Li–S batteries and high-voltage Li-ion batteries, are performed to demonstrate the significantly improved cycling and rate performance of batteries with the use of the GLC-Al foil as current collectors. The cell using the GLC-Al foil can greatly reduce the potential polarization in Li–S batteries and can obtain a reversible capacity of 750 mAh g–1 over 100 cycles at 0.5C. Even with high-sulfur-loading cathodes, the Li–S battery at 1C still maintains over 500 mAh g–1 after 100 cycles. In high-voltage Li-ion batteries, the GLC-Al foil significantly improves the high-rate performance, showing an increased retained capacity by over 100 mAh g–1 after 450 cycles at 1C compared to the bare foil. It is believed that the developed GLC-Al foil brings new opportunities to enhance the battery life of lithium-based batteries.