Khalil Amine

● Cathode materials based on the AB₂O₄ spinel structure have been studied extensively since the mid-1980s due to their stability, high lithium-ion diffusion, and large number of materials that crystallize with this stoichiometry. In 1996, Amine and co-workers reported the synthesis and electrochemistry of the ordered spinel LiNi_0.5Mn_1.5O₄ (1996), a cathode often called '5V spinel". Its notable for its stable high voltage with a typical capacity of 125 mAh/g. The compound operates using only the nickel content as the active redox species while the structure inhibits charge compensation by oxygen evolution.

● Amine and co-workers have been active in the studying the lithium-ion cathode materials termed NMC cathodes (patent issued 2005). The materials structure is based on intergrowths of constituent nano-domains of two closely related layered oxides. They are widely used cathode materials in consumer electronics and electric vehicles.[10] NMC technology has been incorporated into multiple batteries types around the world including those that powered GM's Chevy Volt and Bolt.[11][12][13][14][15] Depending on the lithium content, these materials show an activation step on the first charging cycle that creates a heterogeneous electrochemically active material with capacities greater than 220 mAh/g.

● One of the instabilities of NMC cathodes involves the redox activity of the highly charged cations at the surface against the solvent molecules of the organic electrolyte. In 2012 Amine and Prof Yang Kook Sun from Hanyang University, [16][17] reported an improvement over the standard NMC cathode by devising a synthetic strategy that slightly orders the constituent cations to create a gradient structure that allows for the surface to be less reactive than the bulk. An advanced version of the NMC cathode technology allows for a wide range of formulations and compositions[18] to be created across each particle to increase both energy and stability at high voltage.[17]

● Lithium-air technology, including a new series of catalysts (2007) developed with Larry Curtiss of Argonne National Laboratory for Lithium-air energy storage systems that increase reversibility, was developed to reduce the overpotential observed in air-based systems associated with the needed electron transfer reactions. [19] [20] In 2013 they improved on the system by developing a closed oxygen system that results in a significant simplification of the purification and storage system. The system stores energy in the couple going from superoxide (O₂⁻) anion to the peroxide (O₂⁻²) anion. The net reaction is (LiO₂ +Li –-> Li₂O₂).[21]