Incorporation of TiB2 additive into MnO2 cathode and its influence on rechargeability in an aqueous battery system

Electrochemical and surface characterization have been conducted to establish the role of small amounts (1, 3 and 5 wt.%) of titanium diboride (TiB2) additive into manganese dioxide (MnO2) cathode with Zn as an anode in an aqueous saturated lithium hydroxide electrolyte battery. The incorporation of small amounts of TiB2 additive into MnO2 was found to improve the discharge capacity from 150 to a maximum of 220 mAh/g. The electrode reaction of MnO2 with TiB2 in this aqueous electrolyte is shown to be lithium insertion while suppressing the proton insertion mechanism. This mechanism is confirmed using various techniques i.e. X-ray diffraction (XRD), Scanning electron microscopy (SEM), Fourier transform infra-red spectroscopy (FT-IR), Transmission electron microscopy (TEM) and Secondary ion mass spectrometry (SIMS) analysis on the discharged cathode material. The influence of the TiB2 additive on the performance of MnO2 as a cathode and its cycling ability has been determined. (C) 2008 Elsevier B.V. All rights reserved.