Charging the cells above a conventional voltage of 4.2 V is a promising attempt to increase the energy density of Lithium Cobalt Oxide (LCO), however, the problem of crystal instability at high voltage that leading deterioration of cycle performance needs to be urgently resolved. In this work, as an effective and easy approach to improve the cycle performance and crystal stability of LCO cycling at 4.5 V high voltage, we demonstrate direct surface modification of a LCO cathode by poly [N,N-bis(2-cryano-ethyl)-acrylamide]. The results of SEM, TEM and XRD all indicate that the crystal structure of polymer coating LCO remains unchanged after cycling at 4.5 V high voltage for 60 times. Furthermore, the XPS study of valence of cobalt on the surface of LCO demonstrates that cobaltic ion of polymer coating LCO can be reduced to cobaltous ion after charging the cell. Thus, the activity of the crystal surface can be weakened, as a result, the stability is improved, leading to the performance improvement.
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http://dx.doi.org/10.1038/s41598-018-19176-6 | DOI Listing |
ACS Nano
January 2025
School of Engineering, RMIT University, 124 La Trobe Street, Melbourne, Victoria 3001, Australia.
Modern-day applications demand onboard electricity generation that can be achieved using piezoelectric phenomena. Reducing the dimensionality of materials is a pathway to enhancing the piezoelectric properties. Transition-metal dichalcogenides have been shown to exhibit high piezoelectricity.
View Article and Find Full Text PDFChem Commun (Camb)
January 2025
Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge CB21EW, UK.
Metal-air batteries are promising energy storage systems with high specific energy density and low dependence on critical materials. However, their development is hindered by slow kinetics, low roundtrip efficiency, deficient capacity recovery, and limited lifetime. This work explores the effect of cycling protocols on the lifetime of Li-O cells, and the interplay between electrolyte composition and the upper cut-off voltage during charge.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
School of Sciences, Beihua University, Jilin 132013, China.
The search for new anode materials with high lithium-ion battery (LIB) capacity has attracted considerable attention due to the increasing need for electrical power. Here, we utilized first-principles calculations to develop a honeycomb-structured BCN monolayer, which exhibits an ultra-high Li-ion storage capacity of 2244 mA h g as an anode material for LIBs. Furthermore, the calculations show that the BCN monolayer has a comparatively small diffusion barrier of 0.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
University of Science and Technology of China, Division of Nanomaterials & Chemistry, Hefei National Laboratory for Physical Sciences at Microscale, CHINA.
Electrolysis of carbon dioxide (CO2) in acid offers a promising route to overcome CO2 loss in alkaline and neutral electrolytes, but requires concentrated alkali cations (typical ≥3 M) to mitigate the trade-off between low pH and high hydrogen evolution reaction (HER) rate, causing salt precipitation. Here we report a strategy to resolve this problem by introducing tensile strain in a copper (Cu) catalyst, which can selectively reduce CO2 to valuable multicarbon products, particularly ethylene, in a pH 1 electrolyte with 1 M potassium ions. We find that the tension-strained Cu creates an electron-rich surface that concentrates diluted potassium ions, contributing to CO2 activation and HER suppression.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
National Engineering Research Centre for Mg Alloys, Chongqing University, Chongqing 400044, PR China.
Rechargeable Mg batteries are promising candidates for achieving considerable high-energy-density. Enhancing the energy density can be achieved by integrating metallic Mg anodes with conversion-type cathode materials, which are characterized by multi-electron transfer process and elevated specific capacities in contrast to intercalation-type materials. Despite these advantages, the conversion-type cathodes still have some challenges of substantial volume expansion, sluggish diffusion kinetics and intricate mesophase evolution during repeated electrochemical reactions.
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