Electrochemical properties of lead oxide films obtained by spray pyrolysis as negative electrodes for lithium secondary batteries

Abstract

Lead(II) oxides in bulk and thin film form were assessed as electrodes for lithium rechargeable batteries. Films were prepared by spray pyrolysis of aqueous solutions of Pb(CH 3–COO) 2·2H 2O and deposited onto lead substrates at 175°C. Films heated at 250°C were found to consist of well-crystallized tetragonal PbO and evolve to the orthorhombic polymorph with prolonged heating. Cycling of the cells at a current density of 0.25 mA/cm 2 over the range 1.0–0.0 V led to the formation of various Li y Pb alloys. Cells made from bulk oxides, whether tetragonal or orthorhombic, were found to exhibit poor performance (their capacity rapidly faded with cycling). By contrast, PbO film electrodes exhibited reversible capacity above 500 mA h/g beyond 40 cycles. The lead substrate must thus appreciably influence the electrochemical properties of the cell by facilitating adhesion of Li y Pb microcrystals to its surface, thereby favoring alloying/de-alloying processes.