Aqueous Li-Ion rechargeable batteries (ARLB) could be a promising candidate for a low cost and potentially green battery technology with medium energy level. Nevertheless, their practical interest is mainly linked to the increase of their nominal voltage beyond the water electrochemical stability window. This paper deals with the use of the diazonium chemistry for increasing water reduction overvoltage through the films formed on the electrode surface though their reduction. According to the chemistry chosen, we have put in evidence that the use of difunctional diazonium doesn't limit the performances of the positive LFP electrode on aqueous electrolyte and allows increasing from 200 mV to 400 mV. the water reduction overpotential. (C) 2013 The Electrochemical Society. All rights reserved.