Investigation of Fluorine and Nitrogen as Anionic Dopants in Nickel-Rich Cathode Materials for Lithium-Ion Batteries.

Advanced lithium-ion batteries are of great interest for consumer electronics and electric vehicle applications; however, they still suffer from drawbacks stemming from cathode active material limitations (e.g., insufficient capacities and capacity fading).

New Insights into the Instability of Discharge Products in Na-O2 Batteries.

Sodium-oxygen batteries currently stimulate extensive research due to their high theoretical energy density and improved operational stability when compared to lithium-oxygen batteries. Cell stability, however, needs to be demonstrated also under resting conditions before future implementation of these batteries. In this work we analyze the effect of resting periods on the stability of the sodium superoxide (NaO2) discharge product.

One- or Two-Electron Transfer? The Ambiguous Nature of the Discharge Products in Sodium-Oxygen Batteries.

Rechargeable lithium-oxygen and sodium-oxygen cells have been considered as challenging concepts for next-generation batteries, both scientifically and technologically. Whereas in the case of non-aqueous Li/O2 batteries, the occurring cell reaction has been unequivocally determined (Li2O2 formation), the situation is much less clear in the case of non-aqueous Na/O2 cells. Two discharge products, with almost equal free enthalpies of formation but different numbers of transferred electrons and completely different kinetics, appear to compete, namely NaO2 and Na2O2.

How To Improve Capacity and Cycling Stability for Next Generation Li-O2 Batteries: Approach with a Solid Electrolyte and Elevated Redox Mediator Concentrations.

Because of their exceptionally high specific energy, aprotic lithium oxygen (Li-O2) batteries are considered as potential future energy stores. Their practical application is, however, still hindered by the high charging overvoltages and detrimental side reactions. Recently, the use of redox mediators dissolved in the electrolyte emerged as a promising tool to enable charging at moderate voltages.

Carbon-Free Cathodes: A Step Forward in the Development of Stable Lithium-Oxygen Batteries.

Lithium-oxygen (Li-O2 ) batteries are receiving considerable interest owing to their potential for higher energy densities than current Li-ion systems. However, the lack stability of carbon-based oxygen electrodes is believed to promote carbonate formation leading to capacity fade and limiting the cycling performance of the battery. To improve the stability and cyclability of these systems, alternative electrode materials are required.