Facile preparation of Co₃O₄ nanoparticles incorporating with highly conductive MXene nanosheets as high-performance anodes for lithium-ion batteries

There is considerable scientific interest in the newly available family of MXenes material. An analog as graphene, this two-dimensional (2D) layered material with the structure of transition metal carbides or nitrides exhibits superior electronic conductivity, large interlayer spacing for highly efficient lithium ions diffusion pathways and environmental benignity, making it useful as energy storage material. However, the inferior capability to store lithium ions impedes its wide application in lithium-ion batteries. Therefore, a facile strategy for preparing Co₃O₄ nanoparticles incorporated with MXene nanosheets on Ni foams has been developed. Small-size Co₃O₄ nanoparticles are uniformly distributed within the MXene nanosheets leading to the highly efficient lithium ions and electrons transmission, as well as the prevention for the restacking of MXene nanosheets and huge volume change of the Co₃O₄ nanoparticles. Under the cooperative effect of Co₃O₄ nanoparticles and MXene nanosheets, the Co₃O₄/MXene composite electrode with the mass ratio of Co₃O₄/MXene = 1:1 exhibits an excellent reversible capacity of 1005 mAh g⁻¹ after 300 cycles at the current density of 1 C, which significantly exceeds that of pristine Co₃O₄ electrode. Though the current density climbs to 5 C, the composite electrode remains a stable capacity of 307 mAh g⁻¹ after 1000 cycles. It is demonstrated that Co₃O₄/MXene composite electrode has the potential as an anode for the high-performance lithium-ion batteries.