Long-range ordered intermetallic stabilized 3D porous Si/SixFeAly heterostructure for durable lithium storage

Despite the tremendous potential for high theoretical capacity, silicon anode material still faces formidable challenge that hinder its widespread commercialization in lithium-ion batteries owing to the extreme volume change (over 300%) and intrinsic low electrical conductivity during lithium insertion and extraction. This work focuses on the fabrication of three-dimensional (3D) micro-nano porous Si/Al 9 FeSi 3 /Al 5 FeSi (NP-Si/Si x FeAl y ) composite through a scalable and facile dealloying strategy. Benefiting from multiscale porous architecture and the long-range ordered matrix from the incorporated double intermetallic, NP-Si/Si x FeAl y composite exhibits outstanding lithium storage performance, delivering a high reversible capacity of 529.4 mAh g −1 after 1000 cycles at 500 mA g −1 and retaining 446.1 mAh g −1 after 500 cycles at 1000 mA g −1 , significantly outperforming the NP-Si anode. Remarkably, full-cell configurations coupled with LiFePO 4 cathodes exhibit high reversible capacity of 836.3 mAh g −1 and stable cycling durability for 300 cycles under a current density of 500 mA g −1 , confirming its promising practical applicability. The synergistic role of long-range ordered intermetallic matrix and multiscale ion transport pathways offers new perspectives for developing advanced silicon-based anodes.