Novel 2D LiNi1/3Co1/3Mn1/3O2 hierarchical nanosheets are successfully synthesized through a simple sol-gel strategy with ethanol dispersion of carbon nanotubes as addictive. The nanosheets with thickness of ∼100 nm appear porous and are formed by 100 nm nanoparticles. As cathode for lithium ion battery, the 2D porous hierarchical nanosheets demonstrate high specific capacity of 137.7 mAh g−1 at 20C (1C = 200 mA g−1), which is much higher than those of its counterparts. The high capacity can be still maintained during 100 charge/discharge cycles and the capacity retention is up to 90.1%. The excellent rate capability and cyclability may be attributed to the distinct 2D porous hierarchical structure.