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_1.2Ni_0.13Co_0.13Mn_0.54O₂ as a model of 3d transition metal oxide and Li_1.2Ni_0.13Co_0.13Ru_0.54O₂ 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_1.2Ni_0.13Co_0.13Ru_0.54O₂ cathode was clearly explained by reversible transition metal redox reaction without the oxygen redox process. The EXAFS analysis suggests that Li_1.2Ni_0.13Co_0.13Ru_0.54O₂ cathode also had the small distorted structure around Ru compared with around Mn of Li_1.2Ni_0.13Co_0.13Mn_0.54O₂ cathode. The small distorted structure takes advantages for Li⁺ diffusion, resulting in the high rate performance of the Li_1.2Ni_0.13Co_0.13Ru_0.54O₂ cathode.

具有3d过渡金属或4d过渡金属的富锂固溶体阴极材料是下一代阴极材料的候选者。为了阐明3 d或4 d过渡金属氧化物的速率性能，我们重点研究了两个典型的富锂固溶体阴极。作为3d过渡金属氧化物模型的Li _1.2 Ni _0.13 Co _0.13 Mn _0.54 O ₂和作为含有4 d模型固溶体阴极的Li _1.2 Ni _0.13 Co _0.13 Ru _0.54 O ₂阴极过渡金属。我们已应用操作硬X射线和软X射线吸收光谱来阐明两个阴极的电子畸变和局部畸变。通过XAS测量的结果，通过无氧氧化还原过程的可逆过渡金属氧化还原反应清楚地说明了Li _1.2 Ni _0.13 Co _0.13 Ru _0.54 O ₂阴极的反应机理。的EXAFS的分析表明，锂_1.2镍_0.13钴_0.13钌_0.54 Ò ₂阴极也有围绕茹小失真的结构相比周围的Li的Mn _1.2镍_0.13钴_0.13 Mn _0.54 O ₂阴极。较小的扭曲结构利用了Li ⁺扩散的优势，从而实现了Li _1.2 Ni _0.13 Co _0.13 Ru _0.54 O ₂阴极的高倍率性能。