Nanostructural effect of AlPO4-nanoparticle coating on the cycle-life performance in LiCoO2 thin films

To control the nanostructure of an AlPO4-coating layer, nanoparticles with three AlPO4 phases were synthesized: amorphous, tridymite, and cristobalite phases. These colloids were layered on LiCoO2 thin films by spin coating, and subsequently annealed at 400 degrees C. The interdiffusion variations at the interface were eliminated by the spin-coating method, while the cycle-life performance of the coated cathode depended on the nanostructure of the AlPO4-nanoparticle-coating layer. The LiCoO2 thin-film cathode coated with amorphous nanoparticles and annealed at 400 degrees C showed the best cycle-life performance, and effectively suppressed the degradation of Li+-diffusion kinetics during cycling. (c) 2006 The Electrochemical Society.