(Invited) Synthesizing Cathode Precursors Directly from Lithium Ores

Abstract: With the increasing demand of lithium (Li) used for energy storage, there is a need for diversified Li sources beyond brines. Among the minerals that can satisfy this need, spodumene is most often used for its high Li content and natural abundance. However, the traditional approach to process spodumene is costly and energy-intensive, requiring that the mineral be transformed from its naturally occurring α phase into the more reactive β phase at temperatures exceeding 1000 °C [1, 2]. Acid leaching is then used to extract Li, followed by neutralization to precipitate Li in the form of Li 2 CO 3 , a common precursor for the synthesis of Li-ion battery cathodes. Recently, we have developed an improved procedure to extract Li directly from α-spodumene, which can be performed at lower temperatures and avoids the use of acids. Li 2 CO 3 can be formed with > 90% yield at 750 °C by reacting α-spodumene with inexpensive additives. Following its extraction from spodumene, Li 2 CO 3 can be isolated with high purity by washing the sample using deionized water [3]. The Li extraction process introduced above presents a low-energy and acid-free route to obtain Li 2 CO 3 directly from spodumene, thereby fostering a more sustainable and efficient utilization of natural minerals to produce precursors that are essential for battery industry. We will also demonstrate how the in-situ formation of Li 2 CO 3 opens new opportunities for the direct synthesis of battery materials from raw ores (α-spodumene). References: [1] Karrech, A., et al., A review on methods for liberating lithium from pegmatities, Minerals Engineering , 2020. 145 . [2] Yelatontsev, D. and Mukhachev A., Processing of lithium ores: Industrial technologies and case studies – A review, Hydrometallurgy , 2021. 201 . [3] Shilong, W., Nathan, S., et al., Direct lithium extraction from α-spodumene through solid-state reactions for sustainable Li 2 CO 3 production, under review .