MOF-derived in situ synthesized carbon-coated ilmenite cobalt titanate nanocrystalline, high-stability lithium-ion batteries

Abstract

Recently, due to their high capacity and excellent cycle stability, bimetallic transition-metal oxides have attracted great interest from researchers for use as anode materials in lithium ion batteries. The main disadvantages of bimetallic transition-metal oxides are poor conductivity and easy aggregation during charge and discharge. Here, Co-based metal-organic frameworks (MOFs) are compounded with amorphous titanium oxide by a solvothermal reaction. After the high-temperature alloying of the precursor, carbon-coated CoTiO3 nanocrystallites are synthesized. CoTiO3 nanocrystallites coated by amorphous carbon not only improve the conductivity of the material but also effectively inhibit the aggregation of the CoTiO3 nanocrystallites during charge and discharge. A total of 1400 cycles were cycled at a high current density of 2000 mAg−1, and the reversible capacity was maintained at 610 mAhg−1. In addition, cycling 100 cycles at the current density of 100 mAg−1 reveals the reversible capacity of 630 mAhg−1. Thus, the anode demonstrates excellent lithium storage performance. Then, we characterized the material composition, morphology and specific surface area by means of X-ray diffraction, high resolution transmission electron microscopy and nitrogen adsorption-desorption experiments. These experiments confirmed the unique structure of cobalt-coated CoTiO3 nanocrystallites and excellent lithium storage performance.