To this end, an element different from cobalt such as zirconium and titanium is added to the lithium cobalt oxide, acting as the...http://www.google.fr/patents/US7939207?utm_source=gb-gplus-shareBrevet US7939207 - Non-aqueous electrolyte lithium ion secondary cell with improved cycle characteristics and method for fabricating the same Recherche avanc???e dans les brevets Num???ro de publicationUS7