Metal oxide/carbon nanotubes nano-hybrid materials for energy storage applications

Nano-sized metal oxides are expected to improve the high rate capability of cathode materials for lithium-ion batteries because of the considerably higher effective interfacial area between the nano-sized metal oxide and electrolyte, and its shorter lithium diffusion length during charge/discharge. Since nano-sized metal oxides tend to agglomerate, good dispersion and improved conductivity of an electrode composed of nano-sized oxides is very important for achieving high rate capability. In this study, metal oxide/CNT nano-hybrid materials (LiMn₂O₄/CNT, LiCoO₂/CNT and Li₄Ti₅O₁₂/CNT nanocomposites) were synthesized through selective heterogeneous nucleation and growth of the oxides on CNT surface using microwave-hydrothermal process. In the composites, CNTs acted as a substrate to deposit nano-sized metal oxide and to connect the nanoparticles along 1-dimensional conduction path. The nano-hybrid materials showed excellent high rate capability and good structural reversibility for energy storage applications.