A lithium-air battery and gas handling system demonstrator.

The lithium-air (Li-air) battery offers one of the highest practical specific energy densities of any battery system at >400 W h kg. The practical cell is expected to operate in air, which is flowed into the positive porous electrode where it forms LiO on discharge and is released as O on charge. The presence of CO and HO in the gas stream leads to the formation of oxidatively robust side products, LiCO and LiOH, respectively.

Critical Role of the Interphase at Magnesium Electrodes in Chloride-Free, Simple Salt Electrolytes.

Magnesium (Mg) batteries are a potential beyond lithium-ion technology but currently suffer from poor cycling performance, partly due to the interphase formed when magnesium electrodes react with electrolytes. The use of magnesium bis(trifluoromethanesulfonyl)imide (Mg(TFSI)) electrolytes would enable high-voltage intercalation cathodes, but many reports identify poor Mg plating/stripping in the electrolyte solution due to a passivating interphase. Here, we have assessed the Mg plating/stripping mechanism at bulk Mg electrodes in a Mg(TFSI)-based electrolyte by cyclic voltammetry, Fourier-transform infrared spectroscopy, and electron microscopy and compared this to the cycling of a Grignard-based electrolyte.

Molecular redox species for next-generation batteries.

This Tutorial Review describes how the development of dissolved redox-active molecules is beginning to unlock the potential of three of the most promising 'next-generation' battery technologies - lithium-air, lithium-sulfur and redox-flow batteries. Redox-active molecules act as mediators in lithium-air and lithium-sulfur batteries, shuttling charge between electrodes and substrate systems and improving cell performance. In contrast, they act as the charge-storing components in flow batteries.