Engineering micro-nano structures of SiOC via boron doping-induced self-assembly for superior cyclic stability of lithium-ion batteries

Micro-nano structures present significant potential for transformative advancements in secondary battery technology. Through tailoring micro-nano architectures and establishing efficient ion/electron transport networks, it can alleviate stress fluctuations during cycling, balance the trade-off between high density and porosity, reduce internal impedance, and ultimately enhance the energy density of batteries. In this study, we report the fabrication of hollow porous SiOCB (Hp-SiOCB) powders with a three-dimensional (3D) interconnected micro-nano framework via an innovative boron doping-induced interconnection-assembly strategy. The 3D interconnected micron-scale network, featuring nanoscale channels, enables rapid Li + intercalation while maintaining electrode compactness. The Hp-SiOCB electrode with optimized structure demonstrates low charge transfer resistance (∼80 Ω), excellent rate performance (reversible specific capacities of 473, 387, and 284 mAh g −1 at 1.0, 2.0, and 5.0 A g −1 , respectively), and outstanding cycling stability, retaining 99% of a 598 mAh g −1 capacity after 300 cycles at 0.5 A g −1 . Further in situ investigations and COMSOL multiphysics finite element simulation provide further insight into the volume expansion behaviour of the Hp-SiOCB during the lithiation/delithiation processes, demonstrating the exceptional structural stability and cyclic stability. • A boron doping-induced interconnection-assembly strategy is employed. • SiOCB with 3D interconnected micro-nano structure was constructed and carefully analyzed through a series of characterization. • The boron doping and micro-nano structures enhance the rate capability and cycling stability of SiOCB anodes. • The micro-nano structure enables control of volume expansion and electrode stabilization during lithiation.