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 Co 3 O 4 nanoparticles incorporated with MXene nanosheets on Ni foams has been developed. Small-size Co 3 O 4 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 Co 3 O 4 nanoparticles. Under the cooperative effect of Co 3 O 4 nanoparticles and MXene nanosheets, the Co 3 O 4 /MXene composite electrode with the mass ratio of Co 3 O 4 /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 Co 3 O 4 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 Co 3 O 4 /MXene composite electrode has the potential as an anode for the high-performance lithium-ion batteries. The scheme illustrates a facile strategy of mixing MXene nanosheets and Co 3 O 4 NPs to form the Co 3 O 4 /MXene composite. The composite electrode with the mass ratio of Co 3 O 4 /MXene = 1:1 fabricated by this strategy delivers an excellent capacity of 1005 mAh g−1 after 300 cycles at the current densities of 1 C (C = 890 mA g−1). Image 1 • Co 3 O 4 nanoparticles/MXene nanosheets composite was prepared on the nickel foams. • MXene nanosheets acted as a buffer to accommodate the volume change and prevent the agglomeration of Co 3 O 4 nanoparticles. • MXene nanosheets were used to improve the conductivity of the electrode. [ABSTRACT FROM AUTHOR]