3D δ-MnO2 nanostructure with ultralarge mesopores as high-performance lithium-ion battery anode fabricated via colloidal solution combustion synthesis

Metal oxides with uniform mesoporous structure demonstrate great potential as high-performance electrode materials for lithium-ion batteries. In this study, a three-dimensional δ-MnO2 nanostructure with ultralarge close-packed mesopores composed of nanoscale building crystals is synthesized on a large-scale through an energy- and time-efficient colloidal solution combustion synthesis method. Its unique structural features can accommodate large volumetric expansion/contraction during cycling, provide a shortened diffusion paths of lithium-ions, extensive contact area with electrolyte and suppress the pulverization and aggregation during charge/discharge cycles. As the anode of lithium-ion battery, δ-MnO2 shows a high lithium storage capacity of 905 mAh g−1 at 0.1 A g−1, excellent cycling performance after 200 cycles at 1 A g−1 and rate capability. This economical method with its exceptional advantages can be extended to produce other functional materials with controlled mesoporous nanostructures for high-performance lithium-ion batteries.