Carbon aerogel capsulated cobalt oxides with nanomicro-hierarchical architectures as anodes for lithium-ion batteries

Abstract

N-doped carbon aerogel capsulated Co₃O₄ (Co₃O₄@NCA) is prepared via a hydrothermal method using an N-doped carbon aerogel (NCA) as a conductive carbon matrix and coating layer. Kinetic parameters are investigated using CV and GITT methods, and the improved performance could be ascribed to rapid lithium-ion diffusion and enhanced pseudocapacitance contribution induced by the introduction of carbon aerogel conductive matrices and the construction of porous nanomicro-hierarchical architectures, which endow the material with a large surface area, good conductivity, abundant pore channels, and plentiful defects and active sites, thus greatly increasing the lithium storage capacity. Used as an anode for lithium-ion batteries, Co₃O₄@NCA-1 displays a reversible capacity of 600.2 mA h g⁻¹ during the 200th cycle under 100 mA g⁻¹, 5.13 times larger than the specific charge capacity of 116.8 mA h g⁻¹ for Co₃O₄ samples. Even if the current density is increased to 1 A g⁻¹, it has 4.48 times the charge capacity of pure Co₃O₄. The Co₃O₄ modification strategy using NCA as a matrix to fabricate nanomicro-hierarchical architectures demonstrates potential applications in the energy storage field.