High performance mesoporous C@Se composite cathodes derived from Ni-based MOFs for Li-Se batteries

A mesoporous carbon matrix derived from MOF-Ni prepared via a hydrothermal method was used for encapsulating selenium as a cathode material for Li-Se batteries. Thermogravimetric analysis and energy-dispersive X-ray analysis confirm that selenium is highly homogeneously distributed in the composite with a mass loading up to 48%. It exhibits an initial discharge capacity of 599.7 mA h g(-1) and retains 417 mA h g(-1) with a high coulombic efficiency of 99.9% after 100 cycles at a high rate of 3C, of which the excellent electrochemical performance is mainly attributed to the high conductivity and the hollow structure of the carbon matrix.