The discharge characteristics of manganese dioxide (γ-MnO2 of electrolytic manganese dioxide (EMD) type) as a cathode material in a Zn-MnO2 battery containing saturated aqueous LiOH electrolyte have been investigated. The X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) data on the discharged material indicate that lithium is intercalated into the host structure of EMD without the destruction of its core structure. The XPS data show that a layer of insoluble material, possibly Li2CO3, is deposited on the cathode, creating a barrier to H2O, thus preventing the formation of Mn hydroxides, but allowing the migration of Li ions into the MnO2 structure. The cell could be reversibly charged with 83% of voltaic efficiency at 0.5 mA/cm2 current density to a 1.9 V cutoff voltage. The percentage utilization of the cathode material during discharge was 56%.
- Aqueous battery
- Lithium insertion