LITHIUM-ION CELLS WITH AQUEOUS-ELECTROLYTES

The electrochemical intercalation of lithium can occur in aqueous electrolytes provided that the host material, the Li+ ion concentration and the pH, are carefully selected. Therefore, rechargeable cells with aqueous electrolytes based on the intercalation of lithium in both electrodes can be made. Here we describe some examples of these cells including Li1-xMn2O4/Li1+xMn2O4, Li1-xMn2O4/gamma-Li0.36MnO2, and LiMn2O4/VO2(B) using several aqueous electrolytes. The voltage vs. charge relation for these aqueous cells predicted from the difference of the voltages of Li/LiMn2O4, Li/gamma-Li0.36MnO2, and Li/VO2(B) nonaqueous cells is in excellent agreement with experiment, proving that lithium intercalation is occurring in the cells with aqueous electrolytes. The cells have poor cycle life (approximately 25 cycles) for reasons that are not yet understood.