Scale-up production of high-tap-density carbon/MnO_x/carbon nanotube microcomposites for Li-ion batteries with ultrahigh volumetric capacity

Electrode materials with high tap density are important for their practical application to achieve high volumetric energy density Li-ion batteries. In this work, large-scale fabrication of microsized carbon/MnO_x/carbon nanotube composites by a low-cost spray-drying method is reported. The carbon/MnO_x/carbon nanotube is characteristic of microspherical morphology consisting of interconnected carbon nanotubes and nano-MnO_x with an exterior carbon coating. The micropacking enables the composite to exhibit a tap density as high as 2.54 g cm⁻³. When evaluated as anode materials for Li-ion batteries, the high-tap-density carbon/MnO_x/carbon nanotube electrode delivers a specific capacity of 927 mAh g⁻¹ after 100 cycles, corresponding to an ultrahigh volumetric capacity of 2355 mAh cm⁻³. The carbon network also has dual-functions of excellent electrical conductivity and good mechanical elasticity for the MnO_x to sustain superior rate and cycling properties. The scale-up production method provides a reliable practical avenue of fabricating high-tap-density metal-oxide materials for high-performance Li-ion batteries.