Electrochemical characterization of NaFe2(CN)6 Prussian Blue as positive electrode for aqueous sodium-ion batteries

The electrochemical performance of sodium Prussian Blue Na1-xFe1+(x/3)III[Fe-II(CN)(6)]center dot yH(2)O in aqueous electrolyte is here reported. Remarkable cycling stability and coulombic efficiency close to 100% have been achieved by suppressing the process at high voltage since results in Na-PB peptization and electrode disintegration. Under these conditions, this material is able to deliver 65 mAh g (1) of capacity, which is slightly higher than the capacity obtained in organic electrolyte despite the voltage window used in aqueous electrolyte is narrower. This is possible thanks to the significant reduction of overpotential in aqueous medium which is here discussed and compared with previous results obtained with NaFePO4 in aqueous electrolyte. (C) 2016 Elsevier Ltd. All rights reserved.