The 9th International Conference on Energy, Resources, Environment and Sustainable Development (ERESD 2022)

Designing an eco-friendly and cost-effective process that is ready for commercial implement prior to the time frame of 2025-2030 is urgent for recovering valuable materials, e.g., Li, Co, Ni, etc., from the end-of-life lithium-ion (EoL Li-ion) batteries aiming waste treatment and reduce CO₂ emission from metal extraction from ore. This is because (1) by coupling with Li-ion battery energy storage, power-generation utilities are entering into achieving carbon neutral (e.g. net zero) electricity production with expanded renewable power generation; and (2) 2.1 million EVs have been sold globally in 2019 with the total stock of 7.2 million EVs, and the year-to-year increase in EV registration is approximately 40%.^{[1. https://www.iea.org/reports/global-ev-outlook-2020]} Under such a scenario, by assuming that the average lifespan of the Li-ion batteries is 8-10 years, it is expected that, by 2030, recycling of approximately 200 kilotons of EOL Li-ion batteries globally will be necessary to sustain economic growth and protect environment.^{[2. https://spectrum.ieee.org/lithiumion-battery-recycling-finally-takes-off-in-north-america-and-europe]}
To address this urgency, a thermal-conversion process assisted by H₂ has been invented and developed at University of Kentucky (UK) by utilizing a H₂-fueled reactor to effectively recover the metal elements/alloys from the EOL Li-ion battery followed by separating the individual species in a continuously stirred reactor. Such a process offers the significant advantage versus the existing technologies, which is no in need of strong acids and reducing agents in the process. Using LiCoO₂ as an example is sketched in Figure 1. LiCoO₂ powders are reduced in a H₂-fueled fluidized bed reactor at an elevated temperature. The product is a solid mixture of Li₂O and Co. Since Li₂O is highly soluble in H₂O and Co is magnetic at room temperature, a continuously stirred reactor is subsequently used to separate the elemental Co solids from the Li(OH)-concentrated brine.
In this meeting, UK will present (1) the metal recovery results using a bench-scale process, (2) improving the process performance by altering the operating parameters, e.g., gas flow rate, temperature, etc., and (3) disclosing the underlying mechanisms for decomposing lithium oxides under reducing environments.