Engineering hetero-epitaxial nanostructures with aligned Li-ion channels in Li-rich layered oxides for high-performance cathode application

As a promising cathode material for Li-ion batteries (LIBs), Li-rich layered oxide (LLO) has attracted the most interest due to its superior performance and attractive characteristics, such as, extremely high capacity and energy density, low cost, and environmental friendliness. However, LLO cathode materials are facing a fundamental challenge of performance degradation as a result of the intrinsically poor rate capability and structural instability. Here we report the synthesis of high performance spinel/LLO heterostructured composite with aligned Li-ion channels by a composition modulated epitaxy method. The hetero-epitaxial nanostructure provides highly anisotropic Li-ion diffusion channels in spinel/LLO composite that significantly improve the electrochemical performance. Discharge capacities as high as 307, 282, 269, 227, 200 mA h g(-1) at 0.1, 0.5, 1.0, 3.0 and 5.0 C rates, respectively, and reversible capacity of 286 mA h g(-1) after 100 cycles at 0.2 C rate can be attained. This work sheds light on the comprehensive design of heterostructured composites for high-performance electrode applications and opens up new opportunities for next-generation LIBs.