Zero‐Strain High‐Capacity Silicon/Carbon Anode Enabled by a MOF‐Derived Space‐Confined Single‐Atom Catalytic Strategy for Lithium‐Ion Batteries

Developing zero‐strain electrode materials with high capacity is crucial for lithium‐ion batteries (LIBs). Here, a new zero‐strain composite material made of ultrasmall Si nanodots (NDs) within metal organic framework‐derived nanoreactors (Si NDs⊂MDN) through a novel space‐confined catalytic strategy is reported. The unique Si NDs⊂MDN anode features a low strain (<3%) and a high theoretical lithium storage capacity (1524 mAh g ‐1 ) which far surpasses the traditional single‐crystal counterparts that suffer from a low capacity delivery. The zero‐strain property is evidenced by substantial characterizations including ex/in situ transmission electron microscopy and mechanical simulations. The Si NDs⊂MDN exhibits superior cycling stability and high reversible capacity (1327 mAh g ‐1 at 0.1 A g ‐1 after 100 cycles) in half‐cells and high energy density (366 Wh kg ‐1 after 300 cycles) in a full cell. This study reports a new catalog of zero‐strain electrode material with significantly improved capacity beyond the traditional single‐crystal zero‐strain materials.