Li-site, Fe-site and P-site substituted LiFePO4 phosphoolivines were synthesized and examined in terms of crystal structure, electrical conductivity, charge–discharge performance in Li/Li+/LiFePO4-type cells, as well as chemical stability against the LiPF6-EC–DEC electrolyte. Despite possible improvement of electrical conductivity of the substituted phosphoolivines, it seems that the optimization of morphology and reduction of grain size is the most efficient way of improvement of electrochemical performance of LiFePO4, while chemical stability of the substituted materials remains high.