Large Scale Process for Low Crystalline MoO₃-Carbon Composite Microspheres Prepared by One-Step Spray Pyrolysis for Anodes in Lithium-Ion Batteries.

Jung Cho

doi:10.3390/nano9040539

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−1 after 100 cycles, even at a high current density of 1.0 A g−1 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−1 at current densities of 0.5, 1.5, 3.0, and 5.0 A g−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.

Highlights

Lithium-ion batteries (LIBs) have been attractive as the most important type of power source for energy-storage system, electric vehicles, and other electronic devices because of their high specific capacities and energy densities [1,2,3]
A carbon matrix could prevent the aggregation of the active materials during repeated cycles by surrounding them, which increases the structural stability of anode materials [12,13]
The cell assembled with TiO2–graphene composite nanofibers as an anode retained 84% of the reversible capacity after 300 cycles at a current density of 150 mA g−1, which is 25% higher than bare TiO2 nanofibers did under the same test conditions

Summary

Introduction

Lithium-ion batteries (LIBs) have been attractive as the most important type of power source for energy-storage system, electric vehicles, and other electronic devices because of their high specific capacities and energy densities [1,2,3]. The low intrinsic electric conductivity and the large volume expansion of TMOs during a charge/discharge cycle result in rapid capacity fading, which hinders the commercial application of TMOs for anodes in current LIBs [7,8]. To solve these problems, compositing TMOs with carbonaceous materials has been regarded as a possible solution. The simple process introduced in this study is expected to be useful for the large-scale synthesis of TMOs/carbon composite microspheres as practical anode materials for LIBs. the synthesis strategy introduced is generally applied to synthesize various metal TMOs/carbon composites, including NiO, Co3O4, SnO2, and Fe2O3, for a wide variety of applications including energy storage

Sample Preparation

Characterization Techniques

Electrochemical Measurements

Results and Discussion