Phospho-olivine compounds

Among all polyanion-type materials, the phospho-olivine LiMPO4 family, where M can be Fe, Mn, Co and Ni, respectively, having the following redox potentials: 3.5 V, 4.1 V, 4.8 V and 5.2 V vs. Li/Li+, has received particular attention. Nowadays, only LiFePO4 (LFP) is used in commercial LIBs due to its excellent cycling and thermal stability as well as low cost and non-toxicity. However, the main drawback of this material arises from its slow 1D ionic conductivity and poor intrinsic electronic conductivity. Consequently, LFP can only be used with a reduction in particle size to nanometer level, coating with conductive films, or doping in order to enhance the ionic and electronic conductivity.