Design of Low-Stress robust silicon and Silicon-Carbide anode with high areal capacity and high energy density for Next-Generation Lithium-Ion batteries

Utilization of biomass-converted products in the energy industry is a pathway to sustain the demand of high energy lithium cells, and silicon anode could be a solution before the lithium metal. The high percentage of silicon (>10 wt%) in the anode for capacity gain can't prevent crack generation during cycling and results in capacity fading and cell failure. Here, we present a unique anode structure like an in-situ nano-layer of carbon-coated silicon–silicon carbide (Si-SiC@C) from black rice husk ash (BRHA)-biomass. A specific proportion of the “SiC” phase in Si-SiC@C plays a crucial role in the formation of a stable interface, passivation of the Si surface, and suppression of Si cracking, resulting in improved battery cycling performance. Furthermore, the distribution of relaxation times (DRT) experiment was carried out in MATLAB software to more understand the interface mechanism. Nano-indentation and Von-mises stress generation method was used to analyze the mechanical properties of samples. The ‘Si’ and ‘SiC’ phases were distinguished by X-ray Diffraction (XRD) and are thoroughly analyzed via the advanced characterization tools (i.e., FETEM, c-AFM, XPS, etc.). The optimized Si-SiC@C composition showed excellent cyclic stability up to 700 cycles with an areal capacity of ∼2.3 mAh cm⁻² at a rate of 0.2 A g⁻¹ vs. Li/Li⁺. Moreover, a pouch cell is fabricated with the Si-SiC@C (i.e., ∼3.8 mg cm⁻²) as anode and NMC811 as cathode (∼11.5 mg cm⁻²). The developed 300 mAh pouch cell performed excellently (>85 % capacity retention) over 200 cycles. In light of easy and energy-efficient synthesis, robustness, and cyclic stability, the specially designed Si-SiC@C from BRHA can be a promising choice as the next-generation anode material for rechargeable battery applications, particularly for lithium-ion batteries.