Nickel‐Doping Modified Interface Synergized With Hollow Confinement Constructs Highly Stable Silicon Anodes for Long Cycling Lithium‐Ion Batteries

ABSTRACT Silicon‐based materials possess a theoretical specific capacity of 4200 mAh g ⁻¹ , making them an ideal anode material for current high‐energy‐density lithium‐ion batteries. However, their significant volume expansion (>300%) and inherently poor electrical conductivity limit their large‐scale application. In this study, an innovative synergistic design approach was employed to propose a nickel (Ni)‐doped hollow carbon‐coated silicon composite material (Ni/HSi@C). This material integrates structural engineering with a carbon layer coating the hollow silicon structure, thereby facilitating volume changes toward internal expansion. Additionally, phase state regulation and interface optimization were integrated, with Ni‐doping introduced to promote the formation of amorphous silicon while inducing the formation of a stable solid electrolyte interface film rich in LiF during charge–discharge cycles, thereby achieving synergistic optimization. Experimental results indicate that after 1000 cycles at a current density of 1000 mA g ⁻¹ , the specific capacity of Ni/HSi@C remains at 1318 mAh g ⁻¹ . Furthermore, the pouch cell achieves an energy density of 379 Wh kg ⁻¹ . In situ impedance and distribution of relaxation times analysis demonstrate that Ni‐doping significantly reduces interfacial impedance and suppresses electrolyte decomposition.