Facile fabrication of layer-cake-like nano-micro hierarchical structure for high performance Li storage

Abstract

In this work, a cobalt-based nano-micro hierarchical structure is prepared via a facile one-pot hydrothermal process. Showing similar morphology to the traditional Chinese food “thousand-layer-cake”, it integrates both the advantages of microscale size and nanoscale design to achieve an efficient balance between Li storage capacity and tap density. On the one hand, its microscale overall dimensions are beneficial to a high tap density, and prevent excess formation of SEI film. On the other hand, its nanoscale building units and inner voids provide a shortened electron diffusion path and sufficient free space to buffer the volume variation during cycles. After calcination and coating processes, the final Co₃O₄/C exhibited a capacity as high as 739 mA h g⁻¹ after 150 cycles, accompanied by excellent long-term cycle stability and rate performance. This layer-cake-like design may provide new ideas for low-cost synthesis of high tap density anode materials for lithium ion batteries.