Towards Sustainable Circularity? Prospective Life Cycle Assessment of Lithium-Ion Batteries with Bio-Based Materials

This prospective cradle-to-gate life cycle assessment evaluates lithium-ion battery pouch cells utilising novel bio-silica electrolytes and bio-silicon anodes and aims to integrate environmental sustainability and circularity considerations early in process development. Although the bio-silica and bio-silicon are sourced from barley husk bio-waste with minimal upstream burden, current processing routes are energy- and chemically intensive and generate substantial acid waste. Reliance on high-temperature treatments makes renewable electricity essential. Climate-change impact of cells utilising the novel materials falls from 13,200 kg CO₂-eq/kWh at lab-scale to 62 kg CO₂-eq/kWh when certain key parameters were optimised in an industrial scenario. Key levers for impact reduction include increasing active-material capacity, applying pre-lithiation, and optimising anode processing. However, even the best-case manufacturing energy demand (207 kWh/kWh cell) is around double that of conventional giga-factory production, underscoring the need for process innovation. From a circularity perspective, low material yields and high chemical intensity limit net environmental benefits, demonstrating that circular feedstocks do not inherently deliver sustainable outcomes. For developers, the results highlight the importance of more resource-efficient, higher-yield, and less energy-intensive routes to bio-silica and bio-silicon production, including feedstocks with higher silica content. For LCA practitioners, they emphasise challenges of scaling lab data and the scarcity of industrial benchmarks. Overall, bio-waste represents a potentially valuable feedstock for circular battery materials, although realising sustainable circularity depends on advances in processing efficiency and system-level optimisation.