Formation of graphene-like 2D spinel MnCo₂O₄ and its lithium storage properties

Two-dimensional (2D) materials fulfill the requirements for fast lithium storage due to the large exposed surface area and the open shortened path for Li insertion/extraction. Novel graphene-like 2D spinel MnCo₂O₄ powders have been synthesized, which inherit the morphology and structure of special metalorganic precursor (MeO₂C₂H₄) (Me = Co and Mn). When tested in an electrochemical system, it delivers high initial discharge capacities of 1157.3 mAhg^-1 at 0.2 Ag^-1 and 1006.3 mAhg^-1 at 0.4 Ag^-1; and also exhibits advanced capacity retention and superior rate performance (~780.0 mAhg^-1 at 0.2 Ag^-1 and ~550.0 mAhg^-1 at 0.4 Ag^-1 after 200 cycles). Remarkably, the 2D layered structure is retained perfectly after 200 cycles at 0.4 Ag^-1. Hence, the type of unique self-assembly metal-organic precursors could provide a flexible and general way to synthesize 2D layered metal oxides as templates for high-performance lithium-ion batteries.