Radical anion based liquid electrode materials

Electrochemical batteries for wind and solar renewable energy storage have attracted world-wide attention, due to their merits of flexibility, modularity and being environmental friendly. Nowadays, new rechargeable battery systems are highly desired for large-scale electrical energy storage. Here in this paper, we report that alkali metal can be dissolved into aromatic compound-ether solvent to obtain a dark blue solution with high conductivity. This solution consists of alkali metal cation and radical anion generated by electron transfer reaction between alkali metal and aromatic compounds. For instance, sodium and biphenyl can be dissolved into 1,2-dimethoxyethane to obtain a dark blue solution which exhibits high electronic conductivity (8.410-3Scm-1), high ionic conductivity (3.6 10-3Scm-1), low potential 0.09 V vs. Na/Na+ and low cost. Using this solution as the anode, we demonstrate a new rechargeable battery with quinone liquid cathode. It is found that the battery with anthraquinone (AQ) liquid cathode displays long cycle ability, low cost properties. This work proposes a new strategy for designing the electrode materials and rechargeable battery systems. Furthermore, this kind of liquid may possess other unique physical properties and might be used in other devices, like thermoelectric battery.