Shedding Light on the Oxygen Reduction Reaction Mechanism in Ether-Based Electrolyte Solutions: A Study Using Operando UV-Vis Spectroscopy.

Using UV-vis spectroscopy in conjunction with various electrochemical techniques, we have developed a new effective operando methodology for investigating the oxygen reduction reactions (ORRs) and their mechanisms in nonaqueous solutions. We can follow the in situ formation and presence of superoxide moieties during ORR as a function of solvent, cations, anions, and additives in the solution. Thus, using operando UV-vis spectroscopy, we found evidence for the formation of superoxide radical anions during oxygen reduction in LiTFSI/diglyme electrolyte solutions.

2,4-Dimethoxy-2,4-dimethylpentan-3-one: An Aprotic Solvent Designed for Stability in Li-O Cells.

In this study, we present a new aprotic solvent, 2,4-dimethoxy-2,4-dimethylpentan-3-one (DMDMP), which is designed to resist nucleophilic attack and hydrogen abstraction by reduced oxygen species. Li-O cells using DMDMP solutions were successfully cycled. By various analytical measurements, we showed that even after prolonged cycling only a negligible amount of DMDMP was degraded.

The importance of solvent selection in Li-O cells.

We have examined the effect of glyme selection on the cycling behavior of Li-O cells. We conclude that diglyme is the optimal solvent for prolonged cycling. We have also focused on the effect of electrolyte solution instability as compared to other cell components.

Feasibility of Full (Li-Ion)-O Cells Comprised of Hard Carbon Anodes.

Aprotic Li-O battery is an exciting concept. The enormous theoretical energy density and cell assembly simplicity make this technology very appealing. Nevertheless, the instability of the cell components, such as cathode, anode, and electrolyte solution during cycling, does not allow this technology to be fully commercialized.

A single subunit directs the assembly of the Escherichia coli DNA sliding clamp loader.

Multi-protein clamp loader complexes are required to load sliding clamps onto DNA. In Escherichia coli the clamp loader contains three DnaX (tau/gamma) proteins, delta, and delta', which together form an asymmetric pentameric ring that also interacts with psichi. Here we used mass spectrometry to examine the assembly and dynamics of the clamp loader complex.