Edge-Surface-Inter Carbon Nanoarchitecture on Silicon

Abstract

The huge volume changes of silicon (Si) anodes during cycling lead to continuous solid electrolyte interphase thickening, mechanical failure, and loss of electrical contact, which have become key bottlenecks limiting their practical applications. This work presents a trimodal in situ growth strategy for constructing hierarchical carbon nanoarchitecture networks on Si substrates (Si@Gr@CNT). The designed “Edge-Surface-Inter” (E-S-I) architecture exhibits three synergistic features: an edge-protruding structure forming vertical conductive channels for rapid Li + transport, a surface-entangled structure providing mechanical enhancement, and an interbridging structure constructing continuous three-dimensional electron transport networks. The Si@Gr@CNT electrode demonstrates a 63.2% improvement in half-cell rate performance compared with traditional Si@Gr. The E-S-I architecture contributes to suppressing excessive LiF formation through improved local current distribution, devoted to the stable and thinner solid electrolyte interphase layer. The three-dimensional conductive network possesses a significant stress regulation effect, which provides stress release space in the vertical direction and lateral stress buffering through surface flexible entanglement. For practical applications, the full cell assembled with the LiFePO 4 cathode and the Si@Gr@CNT/graphite composite anode delivers high energy density and enhanced durability. This study establishes a strategy for hierarchical carbon nanoarchitectures and provides design insights into high-performance Si-based electrodes.