Lithium–air batteries promise to greatly exceed the energy-storage capacity of conventional lithium-ion batteries and a study shows that they can retain 95% of their capacity even after 100 recharges.

Current is generated in lithium–air batteries when lithium ions from the anode react with oxygen from the air — rather than with a limited volume of oxidizing agent, as in conventional batteries. Peter Bruce and his colleagues at the University of St Andrews, UK, created a lithium–air battery using an electrolyte of dimethylsulphoxide, through which the lithium ions flow, and a porous gold cathode where oxygen is reduced before it reacts with the lithium ions. These materials seem to prevent the side-reactions that have quickly degraded the performance of previous lithium–air batteries.

Science http://dx.doi.org/10.1126/science.1223985 (2012)