Sea-Urchin-like Hierarchical Carbon Spheres with Conical Pores as a Three-Dimensional Lithium Host for Dendrite Suppression

Abstract

Three-dimensional (3D) porous carbon structures have attracted considerable attention in recent years because of their large surface area and porosity, which enable superior lithium accommodation. In this study, we report a sea-urchin-like hierarchical carbon sphere with a conical pore structure for use as a 3D lithium host for dendrite suppression. Electron microscopic images and battery performance results show that the numerous valley-like arrangements in the conical pore structure leads to better accommodation of lithium compared with previously reported 3D porous carbon structures. The core part of the pores induces lithium deposition by functioning as the homogeneously distributed charge center. Nucleation occurs from the inside and affects the subsequent growth of lithium. In addition, the hierarchical 3D porous structure can effectively accommodate lithium, preventing volume expansion. Our proposed carbon scaffold design can substantially suppress dendritic lithium growth, resulting in enhanced battery performance with a long- term cycle life of over 250 cycles at a current density of 0.5 mA cm(-2) and enhanced kinetics at higher current densities up to 5 mA cm(-2).