Morella-rubra-like metal–organic-framework-derived multilayered Co3O4/NiO/C hybrids as high-performance anodes for lithium storage
Co3O4/NiO/C microspheres with a multilayered ball-in-ball hollow nanoarchitecture were synthesized via carbonization and oxidation treatments of Morella-rubra-like CoNi-based metal–organic frameworks (CoNi-MOFs). The shell walls of each ball were entirely composed of uniform nanorods. This unique multilayered hollow structure can strongly mitigate the change in the volume of the electrodes, which maintains the structural integrity of the Co3O4/NiO/C hybrids during the lithiation–delithiation process. In addition, the C scaffolds improve the conductivity of the electrode and function as a buffer material to mitigate the pulverization of Co3O4 and NiO nanoparticles. Therefore, in Li-ion cells, the multilayered Co3O4/NiO/C hybrids exhibit a high reversible capacity (864 mA h g−1 at 1 A g−1), an excellent rate capacity (421 mA h g−1 at 4 A g−1), and a long-lifetime cycling performance (776 mA h g−1, even after 1000 cycles at 1 A g−1) for Li storage.