One-dimensional channel to trigger high-performance sodium-ion battery via doping engineering

Doping is argued to be a promising strategy to optimize the structure, chemistry, and composition of the electrode materials to withstand the strain/stress caused by the repeated intercalation and removal of guest ions. However, the underlying science behind the doping behavior remains elusive owing to the physically microstructural complexity and the lack of spatially diagnostic tools for a detailed dig at microscopic scale. Herein, we propose the feasible doping of mono-/tri-valent ions into the host structure to unravel the correlation between doping chemistry and crystal morphologies. Using a synergistic combination of electron microscopy and synchrotron X-ray tomography, we demonstrate that the open framework of CuS model is blocked by the doping of trivalent ion (Fe3+). In contrast, a one-dimensional (1D) channel from "surface to bulk" can be created by the doping of monovalent ions (Na+), which governs the dynamic transmission of the guest ions. The surface and bulk microstructure can be modulated to trigger high-performance sodium-ion batteries (SIBs) by the doping chemistry, suggesting an electro-chemo-structural interplay. Such a 1D channel is of fundamental significance for the design of anode materials with high-rate capability.