Li-rich solid solution cathode materials having 3d transition metals or 4d transition metals are the candidate of next generation cathode material. In order to clarify the rate performance of 3d or 4d transition metal oxides, we focused two typical Li-rich solid solution cathodes; Li Ni Co Mn O as a model of 3d transition metal oxide and Li Ni Co Ru O cathode as a model solid solution cathode containing 4d transition metal. We have applied operando hard and soft X-ray absorption spectroscopies clarify electronic and local distortion of both cathodes. From the results of XAS measurements, the reaction mechanism of Li Ni Co Ru O cathode was clearly explained by reversible transition metal redox reaction without the oxygen redox process. The EXAFS analysis suggests that Li Ni Co Ru O cathode also had the small distorted structure around Ru compared with around Mn of Li Ni Co Mn O cathode. The small distorted structure takes advantages for Li diffusion, resulting in the high rate performance of the Li Ni Co Ru O cathode. 1.2 0.13 0.13 0.54 2 1.2 0.13 0.13 0.54 2 1.2 0.13 0.13 0.54 2 1.2 0.13 0.13 0.54 2 1.2 0.13 0.13 0.54 2 1.2 0.13 0.13 0.54 2 +