Controlled synthesis of CoO/C and Co/C nanocomposites via a molten salt method and their lithium-storage properties

Abstract

We report a facile molten salt approach for the fabrication of CoO and Co nanoparticles, which homogeneously embedded in two-dimensional (2D) amorphous carbon nanosheets as an advanced anode materials for high-performance lithium-ion batteries (LIBs). With the aid of Na₂SO₄ particles, the ultra-small CoO/C or Co/C hybrid nanocomposites were synthesized simultaneously through a single heating procedure using the Co(OH)₂@OA complex as the precursors for both CoO(Co) and thin carbon layers. The hybrid nanocomposites (C500, C600) exhibited an unexpected initial discharge capacity of 1618.2 and 873 mA h g⁻¹ and high reversible specific capacity (642.1 and 500 mA h g⁻¹ over 50 cycles at 70 mA g⁻¹). The design of ultrafine CoO (Co) nanoparticles encapsulated with thin carbon layers can not only achieve long cycle life, but also effectively avoid the particle cracking, pulverization and aggregation upon cycling. Moreover, the findings open new paths for the exploiting of advanced active materials and electrolytes for Li ion batteries and other energy storage devices.