Pore perforation of graphene coupled with in-situ growth of Co 3 Se 4 for high-performance Na-ion battery.

Graphene-based nanomaterials have sprung up as promising anode materials for sodium-ion batteries due to the intriguing properties of graphene itself and the synergic effect between graphene and active materials. However, the two-dimensional graphene sheet only allows the rapid diffusion of sodium ions along the parallel direction while that of the vertical direction is difficult, limiting the rate capability of graphene-based electrode materials. To tackle this problem, pore-forming engineering has been employed to perforate graphene and concurrently achieve the in-situ growth of Co 3 Se 4 nanoparticles. The generation of in-plane nanohole breaks through the physical barriers of the graphene nanosheets, enabling the fast diffusion of electrolyte ions in the longitudinal direction. In addition, this design limits the aggregation of Co 3 Se 4 nanoparticles because of the high affinity of Co 3 Se 4 on graphene. Benefiting from the high conductivity and fast ion transport bestowed by the ingenious architecture, the Co 3 Se 4 /holey graphene exhibits a remarkable rate performance of 519.5 mAh g -1 at 5.0 A g -1 and desirable cycle stability. Conclusions drawn from this investigation are that the transport of sodium inside the graphene-based composites is crucial for rate performance enhancement and this method is effective in modifying graphene-based nanomaterials as potential anode materials. This article is protected by copyright. All rights reserved.