Assembling MnCo2O4 nanoparticles embedded into MXene with effectively improved electrochemical performance

•MnCo2O4 nanoparticles were embedded into MXene sheets using Co(OAc)2 and Mn(OAc)2 as intercalators by a simple hydrothermal method.•The optimized MXene/MnCo2O4–2# electrode exhibits a high specific capacity of 806.67 f g−1 at 1 a g−1 and excellent cycle performance.•The assembled MXene/MnCo2O4–2#//AC device achieves an energy density of 26.8 Wh kg−1 at a power density of 2.88 kW kg−1.