Hierarchical porous LiNi1/3Co1/3Mn1/3O2 with yolk-shell-like architecture as stable cathode material for lithium-ion batteries

摘要

The relatively sluggish lithium ion diffusion of LiNi1/3Co1/3Mn1/3O2 (NCM) is one of the fatal factors which can significantly prevent its widespread usage in high-power applications. In this work, the monodispersed hierarchical porous yolk-shell-like LiNi1/3Co1/3Mn1/3O2 (YS-NCM) with exposure to {010} electrochemical active facets was successfully synthesized, aiming to elevate the lithium ion diffusion ability and thus to enhance the electrochemical performance. The hierarchical porous nano-/microsphere morphology as well as the voids between the yolk and the shell allow for shortened Li+ diffusion pathways, leading to improved Li+ diffusion capability. These voids are also beneficial for providing more buffers for the volume changes during repeated charge and discharge. Additionally, the exposure of {010} electrochemical active facets provides more open structure for unimpeded Li+ migration. Therefore, by this design strategy, the lithium ion transport kinetics is greatly improved, yielding superior electrochemical performances. When examined as the cathode material for lithium-ion batteries (LIBs), the YS-NCM-based cells have achieved superior rate capability and stable cycling performance, rendering it as a promising cathode candidate for practical lithium-ion battery applications.