Effect of Pb doping on structural and electrochemical properties of combustion synthesised LiCoO₂ powder

Pb-doped LiCoO₂ cathode materials, containing 0–10 mol% of Pb were synthesised by the starch-assisted combustion technique. X-ray diffraction analyses revealed the existence of rhombohedral LiCoO₂ (R-3m) for all compounds. Scanning electron microscopy showed a distinct grain growth with increasing Pb content. The synthesised samples are characterised using X-ray photoelectron spectra (XPS), to investigate the elementary states on the system. The electrical conductivity of Pb-doped LiCoO₂ system tends to increase with Pb content significantly. Decrease of the electrode impedance was observed with increase in Pb content in system. An excellent reversible capacity was observed for the cathode containing 5.0 mol% Pb, when 2016 type coin cells were cycled at 0.1 C rate. This has been ascribed to the structural stability induced by Pb doping.