Electrochemical characterization of LiCoO2 as rechargeable electrode in aqueous LiNO3 electrolyte

The development of lithium ion aqueous batteries is getting renewed interest due to their safety and low cost. We have demonstrated that the layer-structure LiCoO2 phase, the most commonly used electrode material in organic systems, can be successful delithiated and lithiated again in a water-based electrolyte at currents up to 2.70 A/g. The capacity is about 100 mAh/g at 0.135 A/g and can be tuned by cycling the electrode in different potential ranges. In fact, increasing the high cut-off voltage leads to higher specific capacity (up to 135 mAh/g) but the Coulomb efficiency is reduced (from 99.9% to 98.5%). The very good electrode kinetic is probably due to the high conductivity of the electrolyte solution (0.17 Scm- 1 at 25 °C) but this behavior is affected by the electrode load.