The enhanced performance of Li-ion batteries based on Co-MOF/MXene composites

Electrospinning is carried out to fabricate Ti(3)C(2)Tx@Co nanocomposite films composed of 2D Ti3C2-encapsulated Co nanoparticles derived from Co-MOF precursors. The unique 1D nanochain structure inherits not only the high electrochemical activity, but also excellent electron and ionic conductivity. The Co nanoparticles with good conductivity and MXene with high electrochemical activity improve the electrochemical properties giving rise to high capacity and good cycling stability. The Ti3C2 flakes partially accommodate the volume changes during Li+ insertion/extraction and the electrospinning technique prevents self-aggregation of Ti3C2 flakes and aggregation of ZIF-67 nanoparticles, consequently producing a larger surface area and more active sites on the flexible anode. As a result, the MXene/Co composite has excellent properties such as a high reversible capacity of 422 mA h g(-1) after 500 charging-discharging cycles at a current density of 1 A/g and retained capacity of 177 mA h g(-1) at a rate of 5 A/g. The materials and strategy have large potential in commercial energy storage devices.