Ball-in-Cage Nanocomposites of Metal-Organic Frameworks and Three-Dimensional Carbon Network: Synthesis and Capacitive Performance
In order to improve the electrical conductivity of metal-organic frameworks (MOFs) which have drawn remarkable attention to the potential application in energy storage field, Co-based zeolitic imidazolate framework (ZIF-67) polyhedron was in-situ integrated into three-dimensional carbon network (3DCN) to construct a Ball-in-Cage (BIC) nanostructure. The introduced 3DCN acting as the electronic pathway can provide the nucleation sites of MOF particles. The further growth of which is confined by the size effect of 3DCN consequently. The BIC frame not only controls the MOF particle size, but also ensures a high electron conductivity of the entire structure. The as-prepared BIC electrode displays an outstanding capacitance of 119 F g-1 at a current density of 0.5 A g-1 and great rate performance as well, which can be expected to be a promising approach to enhance the electrochemical performance of pristine MOFs in the future.