Intercalation of lithium into the vacant sites of a host compound can be achieved electrochemically using nonaqueous electrolytes. The use of aqueous electrolyte is less common because of the reactivity of many lithium intercalation compounds with water. Here, we propose that lithium could be intercalated into the manganese dioxide cathode in a battery using saturated lithium hydroxide as the electrolyte. The positive electrode reaction at MnO2 in this medium is shown to be lithium insertion rather than the usual protonation, and acceptable rechargeability is observed. Using X-ray photoelectron spectroscopy and scanning electron microscope analysis on the discharged cathode material we confirmed the presence of lithium ions in the host structure of MnO2. Further, the incorporation of small amounts (<3 wt %=weight percent) of titanium disulphide (TiS2) additive to the cell MnO2 cathode leads to a significant improvement in cell performance.