Preparation of LiCoO2 thin film consisting of nanosize particles on carbon substrate with the rugged surface via electrodeposition

LiCoO2 thin films composed of nanoparticles were synthesized by hydrothermal treatment of the precursor films electrodeposited on a glassy carbon with a flat surface and on a carbon paper substrate with ruggedness and their electrochemical properties were investigated. LiCoO2 films composed of nanometer-size particles were homogeneously coated on the surfaces of the carbon substrates. The capacity of LiCoO2 film electrodes on the rugged substrate increased in proportion to the deposition charge, whereas the LiCoO2 film on the flat substrate exhibited a proportional limit in the relationship between the deposition charge and rechargeable capacity. The rate performance and cycle stability of the films coated on the rugged substrate with a larger amount of LiCoO2 were superior to those of films with a smaller amount of LiCoO2. This may be caused by the carbon defects which are introduced on the uncoated surface of the substrate during annealing process.