Design Framework for Cobalt and Ni-Free High-Capacity Lithium-Ion Cathodes

Abstract

Growing demand for Lithium-ion batteries for electric transportation and grid-scale storage will inevitably put resource constraints in terms of availability of key critical battery materials such as cobalt, nickel, lithium, and graphite. Specifically limited global reserve of elements such as cobalt and nickel will lead to severe supply chain issues driving the cost and contributing to market uncertainty. Given such scenario, there has been a significant effort in the global research community to develop high performance battery materials derived from relatively earth abundant elements. The talk will highlight ongoing research at PI’s Laboratory and collaborators on developing cobalt-free disorder rock salt (DRX) cathodes for next generation Li-ion. Most practical Li-ion cathode materials have well-ordered structures (e.g., spinel, layered, olivine), while the DRX compounds do not require any cation ordering. Instead, Li transport is achieved by percolation through a cation-disordered within the dense crystalline rock salt structure. Since DRX compounds do not necessitate a layered structure, they do not necessarily require cobalt metal and can be synthesized from an extremely wide variety of common metals, including Ti, Mn, Ni, Al, Nb, Mo, V, Zr, etc. Therefore, such class of materials provides plenty of chemical options for cathode design for Li-ion. Another key enabling aspect for this class of cathodes is the role of fluorine in stabilizing the high voltage oxygen redox and capacity retention. The talk will focus specifically on synthesis and structural design of Li-Mn-Ti-OF based DRX compositions and pathways for improving high voltage redox and stability.This work performed at Oak Ridge National Laboratory is supported by the Assistant Secretary for Energy Efficiency and Renewable Energy, Vehicle Technologies Office, under the Applied Battery Materials Program, of the U.S. Department of Energy under Contract No. DE-AC05-00OR22725