**Jung Sang Cho**

Department of Engineering Chemistry, Chungbuk National University, Chungbuk 361-763, Korea; jscho@cbnu.ac.kr; Tel.: +82-43-261-2489; Fax: +82-43-262-2380

Received: 22 February 2019; Accepted: 27 March 2019; Published: 3 April 2019

**Abstract:** This paper introduces a large-scale and facile method for synthesizing low crystalline MoO3/carbon composite microspheres, in which MoO3 nanocrystals are distributed homogeneously in the amorphous carbon matrix, directly by a one-step spray pyrolysis. The MoO3/carbon composite microspheres with mean diameters of 0.7 μm were directly formed from one droplet by a series of drying, decomposition, and crystalizing inside the hot-wall reactor within six seconds. The MoO3/carbon composite microspheres had high specific discharge capacities of 811 mA h g<sup>−</sup><sup>1</sup> after 100 cycles, even at a high current density of 1.0 A g<sup>−</sup><sup>1</sup> when applied as anode materials for lithium-ion batteries. The MoO3/carbon composite microspheres had final discharge capacities of 999, 875, 716, and 467 mA h g<sup>−</sup><sup>1</sup> at current densities of 0.5, 1.5, 3.0, and 5.0 A g<sup>−</sup>1, respectively. MoO3/carbon composite microspheres provide better Li-ion storage than do bare MoO3 powders because of their high structural stability and electrical conductivity.

**Keywords:** molybdenum oxide; carbon composite; spray pyrolysis; anodes; lithium-ion batteries
