Topologically Robust New Silica Phase Decoupling Intrinsic Zero-Strain Feature and High-Capacity Li+ Storage.

Conventional silicon-based anodes present high specific capacity but show huge volume expansion, whereas the zero-strain anodes generally show low specific capacity, presenting the zero-strain and capacity paradox. Here, inspired by the typical zero-strain anodes (such as Li4Ti5O12) and the high specific capacity of silicon-based anodes, we report a new topologically robust silica phase (TRS) that enables an intrinsic zero-strain feature with high lithium-ion storage performance by fundamentally decoupling capacity from volume expansion. TRS features rigid Si-O bonds with large topological rings, providing sufficient internal space and mechanical robustness to accommodate numerous lithium-ions and achieving an intrinsic zero-strain feature simultaneously. Comprehensive in-situ transmission electron microscope (TEM), in-situ Raman and in-situ X-ray diffraction (XRD) confirm its zero-strain nature, exhibiting constant phase and lattice parameters during (de)lithiation, and revealing reversible lithium-ion solid-solution storage. The TRS anode delivers a high reversible capacity and energy density, which are higher than those of typical reported zero-strain and graphite anodes, and maintains exceptional cycling stability. This topological structural strategy provides a new paradigm for designing next-generation anodes with zero-strain and high lithium-ion storage performance.