Liquid Crystal Phase-Regulated Hierarchical Structures for High-Performance Silicon-Graphene Anodes

Hydrophilic graphene oxide (GO) has emerged as a versatile two-dimensional nanoscale building block capable of being assembled into diverse macroscopic forms to create high-performance graphene-based structures after reduction. For example, solution GO-derived graphene has been extensively studied as a matrix for hosting active electrode materials in high-performance battery electrodes. Increasing the GO concentration allows it to transition from an isotropic colloidal solution to a nematic liquid crystal (LC) phase, thereby enhancing the material properties through the LC-regulated alignment of the GO sheet building blocks. In this study, we fabricated a GO LC-regulated hierarchically macroscopic structure with long-range ordering, resembling an artificial “parent crystal lattice″. Within this structure, silicon (Si) nanoparticles (NPs) were incorporated as the “secondary phase atoms″. This unique architecture facilitates expedited charge transport pathways and mechanically robust backbones, effectively alleviating large volume changes during charge-discharge processes. The resulting Si-graphene electrode, with a mass loading of 4 mg cm^-2, achieved a maximum capacity of 8 mAh cm^-2 at 0.21 mA cm^-2 and maintained a practical capacity of 4.2 mAh cm^-2 at 1.68 mA cm^-2. Moreover, the Si-graphene anode demonstrated excellent cycling stability with a high Coulombic efficiency of 99.5% and nearly 100% capacity retention over 200 cycles.