Heterostructured core?shell ZnMn2O4 nanosheets@carbon nanotubes? coaxial nanocables: a competitive anode towards high-performance Li-ion batteries

In this study, we rationally designed a rapid, low-temperature yet general synthetic methodology for the first time, involving in situ growth of two-dimensional (2D) birnessite-type MnO2 nanosheets (NSs) upon each carbon nanotube (CNT), and we designed the subsequent phase transformation into untrathin mesoporous ZnMn2O4 NSs with a thickness of ?2?3 nm at room temperature to efficiently fabricate heterostructured core?shell ZnMn2O4 NSs@CNT coaxial nanocables with well-dispersed and tunable ZnMn2O4 loading. The underlying insights into the low-temperature formation mechanism of the unique core?shell hybrid nanoarchitectures were tentatively proposed here. When utilized as a high-performance anode for advanced LIBs, the resultant core?shell ZnMn2O4@CNTs? coaxial nanocables (?84.5 wt.% loading) exhibited large specific discharge capacity (?1033 mAh g?1), good rate capability (?528 mAh g?1) and excellent cycling stability (average capacity degradation of only ?5.2% per cycle) at a high current rate of 1224 mA g?1, originating from the distinct core?shell synergetic effect of fast electronic delivery and from the large electrode/electrolyte contacting surfaces/interfaces provided by three-dimensional entangling coaxial CNT-based nanonetwork topology.