Using ion current to probe nanostructured battery materials in different oxidation states

摘要

Ionic currents were used to probe amorphous MnO2, which is a battery cathode material in lithium ion batteries, that was template electrodeposited in polycarbonate cylindrical nanopores. The porous MnO 2 occupies the volume extending approximately 1 mum into the pore from one end and nanovoid channels, in the MnO2, allow for electrolyte solution to pass through from one end to the other.;Presented in this thesis are the results of ionic current studies used to probe ion transport through amorphous MnO2, in different oxidation states, with 100 mM LiClO4 electrolyte in propylene carbonate (PC) solvent. Current-voltage curves, from ionic current-measurements, were unable to resolve excess surface charge in the electrodeposited MnO 2. A comparison of current-voltage curves from when the MnO 2 was cycled between lithium inserted and deinserted oxidation states showed a trend of increasing resistance over a series of three lithium insertion and deinsertion cycles.