The cost and energy density of commercial Li-ion batteries (LIBs) are largely limited by the cathode. Currently, the LIB cathode market is dominated by intercalation type layered transition metal oxides of the general form LiNi_xMn_yCo_1-x-yO₂ (NMC). As the LIB market continues to grow, there is an increasing risk of over-reliance on cobalt and nickel, which not only leads to increased cost and resource depletion, but also raises ethical concerns related to the cobalt mining industry. Hence, there is an urgent need to develop new cathodes based on earth abundant materials.

Disordered rocksalt (DRX) oxides and oxyfluorides have emerged as a promising candidate for next generation LIB cathodes due to their high energy density and ability to utilize low-cost, earth abundant elements such as Mn and Ti. Studies have shown that anionic substitution of oxygen with fluorine enhances electrochemical performance and cycling stability of DRX cathodes. DRX cathodes are traditionally synthesized using high temperature solid-state and high energy mechanochemical routes. While these methods have yielded promising cathodes, they face challenges with fluorine substitution and process scalability. Keeping this in mind, the goal of this research is to develop alternate synthesis routes to prepare DRX oxyfluoride cathodes and identify key structure – property correlations to optimize cathode performance. Our team recently developed a sol-gel based approach to synthesize Li_1.2Mn_xTi_0.8-xO_2-yF_y (y=0-0.2; x=0.4-0.6) DRX oxides and oxyfluorides. This presentation will discuss recent development related to the synthesis, structure, and performance of these cathodes

Acknowledgements

This research was conducted at Oak Ridge National Laboratory, managed by UT Battelle, LLC, for the U.S. Department of Energy (DOE) and is sponsored by the Office of Energy Efficiency and Renewable Energy (EERE) through the Vehicle Technologies Office (VTO).