Porous polyhedral and fusiform Co3O4 anode materials for high-performance lithium-ion batteries

Abstract

Co3O4 is commonly used as a potential anode material for Li-ion batteries (LIBs). In this study, novel porous polyhedral and fusiform Co3O4 powders have been synthesized successfully through the hydrothermal method with different solvents followed by thermal treatment. It is shown that both of the polyhedrons (1.0-3.0μm in side length) and the spindles (2.0-5.0μm in length, 0.5-2.0μm in width) are composed of similar irregular nanoparticles (20-200nm in diameter, 20-40nm in thickness) bonded to each other. Evaluated by electrochemical measurements, both of them have high initial discharge capacities (1374.4 mAhg−1 and 1326.3 mAhg−1) and enhanced cycling stabilities at the low rate (the capacity retention ratios at 0.1C after 70 cycles are 91.6% and 92.2%, respectively). However, the rate capability of the spindles (93.8%, 90.1% and 98.9% of the second discharge capacities after 70 cycles at 0.5C, 1C and 2C, respectively) is better than the polyhedrons’ (only 76.2%, 42.1% and 59.3% under the same conditions). Remarkable, the unique morphologies and special structures may be extended to synthesize other similar transition metal oxides (NiO, Fe3O4, et al.) as high performance anodes for LIBs.