Unveiling the prospects of hydrogen bond networks and multiple chemical bonds in biomass-derived Ni-doped hydrochar for high-performance integrated silicon anodes

Abstract

Considering the large-scale production of lithium-ion battery anode materials, the advantages of silicon-based anodes would be overshadowed if both performance and cost were not properly optimized. However, current preparation methods for silicon‑carbon anodes face challenges such as low efficiency and high energy consumption, limiting the sustainable commercialization. This work proposes a novel, cost-effective method for fabricating silicon‑carbon anodes by utilizing a hydrogen bond network in combination with multiple chemical bonds. Through a one-step hydrothermal method, silicon nanoparticles, nickel foam, and a Ni-doped hydrochar-based amorphous carbon network are assembled into the integrated NF-Si@GC electrode. The calculation demonstrates that multiple chemical bonds between each component in composite structure introduces a built-in electric field across the three materials, which generates a driving force for electron transfer on the surface of Si. As expected, the NF-Si@GC electrode exhibits a high reversible charge capacity of 1454 mAh g⁻¹ at 0.1 A g⁻¹, maintains 970 mAh g⁻¹ at a high areal loading of 1.41 mg cm⁻², and achieves one of the lowest preparation costs for common silicon anodes reported to date. The study of this reaction mechanism provides inspiration for the large-scale production of other battery materials and the scalable manufacturing of high-performance electrodes.