Research Projects

The increasing global demand for lithium, driven by the rapid growth in lithium-ion battery (LIB) usage across electric vehicles and electronics, has raised critical concerns regarding the sustainability, environmental impact, and economic feasibility of conventional lithium extraction methods. Traditional techniques such as solar evaporation and hydrometallurgical leaching are energy-intensive, environmentally taxing, and slow, especially when dealing with dilute lithium sources like brines or battery waste. Concurrently, the rise in end-of-life LIBs presents an opportunity for secondary lithium sourcing. In this context, the present research proposes an innovative, integrated, and eco-friendly approach for lithium recovery that leverages functionalized biochar as both an adsorbent for lithium from brines and a carbonaceous reductant for the carbothermal processing of spent cathodes. The scientific objectives of this study are: Synthesis and modification of biomass-derived carbon materials with selective surface functionalities for lithium adsorption. Utilization of the lithium-loaded biochar as a dual-function material in high-temperature carbothermal reduction of spent cathode materials. Recovery of lithium as lithium carbonate via water leaching. Extraction of cobalt and manganese from the post-reduction residue through acid leaching and co-precipitation. Valorisation of the final carbon residue as an electrode material for supercapacitor applications and a comprehensive life cycle and techno-economic assessment will also be performed. The central hypothesis being tested is that biochar can serve a dual role: first, as a selective lithium adsorbent from low-concentration sources (brines), and second, as a thermochemically reactive reductant for efficient lithium and metal recovery from battery waste. This model is based on the tunable surface chemistry of carbon materials and their high thermal stability and reactivity. The study will also test the feasibility of reusing thermally treated carbon for energy storage, closing the material loop. The experimental methodology includes: (1) preparation and surface modification of biochar via pyrolysis and metal oxide functionalization, (2) lithium adsorption trials under varying pH, concentration, and temperature, (3) dismantling and processing of spent LIBs to extract cathode powder, (4) thermochemical treatment of spent cathodes with lithium-loaded biochar under controlled conditions, (5) post-reduction leaching for lithium recovery as Li₂CO₃, (6) selective leaching and co-precipitation of cobalt and manganese, (7) characterization and testing of residual carbon as a supercapacitor applications and (8) Life cycle study and technoeconomic analysis. If successful, this project will establish a novel circular framework for lithium recovery that eliminates the need for synthetic reductants and hazardous leaching agents, while achieving multi-element recovery and carbon valorization. From a fundamental standpoint, the study will provide insights into the surface-adsorption behaviour of functionalized biochar, its thermal reductive properties, and the coupling of physicochemical transformations across multiple process steps. From an application perspective, the integrated process could offer a scalable, low-cost, and green alternative to current lithium recovery technologies, particularly beneficial for resource-constrained regions such as India. In addition to lithium, the simultaneous recovery of valuable metals such as cobalt and manganese enhances the economic viability of the process, while the carbon-rich residue can be repurposed for energy storage applications such as supercapacitors, further contributing to circular economy and sustainable material utilization.