Enhanced Lithium Storage Performance of α-MoO3/CNTs Composite Cathode

Abstract

Orthorhombic molybdenum oxide (α-MoO3), as a one-layered pseudocapacitive material, has attracted widespread attention due to its high theoretical lithium storage specific capacity (279 mAh/g) for lithium-ion batteries’ cathode. Nevertheless, low conductivity, slack reaction kinetics, and large volume change during Li+ ions intercalation and deintercalation seriously limit the practical application of α-MoO3. Herein, we added a small number of CNTs (1.76%) to solve these problems in a one-step hydrothermal process for preparing the α-MoO3/CNTs composite. Because of the influence of CNTs, the α-MoO3 nanobelt in the α-MoO3/CNTs composite had a larger interlayer spacing, which provided more active sites and faster reaction kinetics for lithium storage. In addition, CNTs formed a three-dimensional conductive network between α-MoO3 nanobelts, enhanced the electrical conductivity of the composite, accelerated the electron conduction, shortened the ion transport path, and alleviated the structural fragmentation caused by the volume expansion during the α-MoO3 intercalation and deintercalation of Li+ ions. Therefore, the α-MoO3/CNTs composite cathode had a significantly higher rate performance and cycle life. After 150 cycles, the pure α-MoO3 cathode had almost no energy storage, but α-MoO3/CNTs composite cathode still retained 93 mAh/g specific capacity.