This work attempts to understand the rate capability of layered transition metal oxides LiNi y Mn y Co1−2y O2 (0.33 ≤ y ≤ 0.5). The rate capability of LiNi y Mn y Co1−2y O2 increase with increasing Co in the compounds and with increasing amount of carbon additives in the electrodes. The lithium diffusion coefficients and electronic conductivities of Li x Ni y Mn y Co1−2y O2 are investigated and compared. The 333 compound has higher diffusivity and electronic conductivity and thus better rate performance than 550. Chemical diffusion coefficients for both delithiation and lithiation of Li x Ni y Mn y Co1−2y O2 investigated by GITT and PITT experiments are calculated to be around 10−10 cm2 s−1, lower than that of Li x CoO2. The electronic conductivity of Li x Ni y Mn y Co1−2y O2 is inferior compared to Li x CoO2 at same temperature and delithiation stage. However, the Li x Ni y Mn y Co1−2y O2 are able to deliver 55%–80% of theoretical capacity at 5 C with good electronic wiring in the composite electrode that make them very promising candidates for electric propulsion in terms of rate capability.