Ultrafast joule heating conversion of rice husk into C/SiOx composite anodes for sustainable lithium-ion batteries: Electrochemical performance and life cycle assessment

Abstract

Transforming agricultural waste into functional lithium-ion battery (LIB) anodes offers a sustainable pathway toward low-carbon energy storage and circular resource utilization. In this work, rice husk (RH) was converted into carbon/silicon oxide (C/SiO x ) composite anodes using a rapid Joule heating (RJH) process (1400–2600 °C, ∼30 s). The study showed that ultrafast carbonization preserved a defect-rich turbostratic carbon framework, while silicon carbide (SiC) phases formed at elevated temperatures through carbothermal reactions. The sample carbonized at 1800 °C exhibited a porous structure with a specific surface area of 74.83 m 2 g −1 , accompanied by structural rearrangement ( I D /I G = 1.033, d 002 = 0.385 nm). Further compositional engineering by optimizing the carbon black loading for RJH increased the initial reversible specific capacity to 389 mAh g −1 , achieving 93.3% capacity retention over 500 cycles and maintaining 214 mAh g −1 at a threefold higher current density, which outperforms commercial graphite anode in terms of cycling stability and rate capability tested under the same conditions. Life cycle assessment (LCA; TRACI method) indicated lower environmental impacts than graphite production, including reduced global warming potential (1.68 vs. 7.08 kg CO 2 -eq), acidification potential (0.00708 vs. 0.0272 kg SO 2 -eq), and non-carcinogenic toxicity (6.07 × 10 −7 vs. 3.20 × 10 −6 CTUh). Overall, this work demonstrates a rapid, low-energy, and environmentally benign strategy for converting RH into sustainable LIB anode materials, with process-specific LCA based on primary experimental data further confirming its environmental benefits and sustainability potential.