Nickel-rich nickel manganese cobalt (LiNixMnyCozO2 x ≥ 0.8) cathode material is widely studied due to its high specific capacity, high energy density, and low toxicity. Despite these advantages, NMC811 (LiNi0.8Mn0.1Co0.1O2) suffers from structural instability and is susceptible to degradation upon exposure to ambient air. Surface coating using silica has been demonstrated to mitigate these issues by acting as a protective barrier against air and electrolyte. In the present study, rice husk was used as a cost-effective and renewable source of silica for coating NMC811. The extracted silica was characterized by an amorphous structure, spherical particles, and a purity of 97.54%. Coating with 1.5 wt.% rice husk-derived silica improved electrochemical performance of NMC811, yielding enhancements in electrical conductivity (3.11 × 10-5 S/cm), lithium-ion diffusion coefficient (9.77 × 10-14 cm2/s), and specific capacity (325.30 mAh/g) in comparison to pristine NMC811 (2.68 × 10-5 S/cm, 3.63 × 10-14 cm2/s, 212.93 mAh/g, respectively). These findings highlight the potential of rice husk-derived silica as sustainable and effective coating material for enhancing the stability and electrochemical performance of NMC811 cathodes. © 2025 The Authors