Collaborative Hollow Porous Structure Design and N Doping to Achieve a Win–Win Situation of “Stable” and “Fast” Lithium Battery

ABSTRACT Polymer‐derived SiOC materials are widely regarded as a new generation of anodes owing to their high specific capacity, low discharge platform, tunable chemical/structural composition, and good structural stability. However, tailoring the structure of SiOC to improve its electrochemical performance while simultaneously achieving elemental doping remains a challenge. Besides, the lithium storage mechanism and the structural evolution process of SiOC are still not fully understood due to its complex structure. In this study, a hollow porous SiOCN (Hp‐SiOCN) featuring abundant oxygen defects is successfully prepared, achieving both the creation of a hollow porous structure and nitrogen element doping in one step, finally enhancing the structural stability and improving the lithium storage kinetics of Hp‐SiOCN. In addition, the formation of a fully reversible structural unit, SiO 3 C─N, through the chemical interaction between N and Si/C, showcases a strong lithium adsorption capacity. Taking advantage of these combined benefits, the as‐prepared Hp‐SiOCN electrode delivers a reversible specific capacity of 412 mAh g −1 (93% capacity retention) after 500 cycles at 1.0 A g −1 and exhibited only 4% electrode expansion. This work offers valuable mechanistic insights into the synergistic optimization of elemental doping and structural design in SiOC, paving the way for advanced developments in battery technology.