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Investigation of Atomic Layer Deposited Al2O3 High Energy Nickel Cobalt Manganese Oxide Cathode Materials

Wednesday, 6 March 2019
Areas Adjacent to the Forum (Scripps Seaside Forum)
S. K. Heiskanen (The University of Rhode Island), S. Jurng, and B. L. Lucht (University of Rhode Island)
High-Energy Nickel Cobalt Manganese Oxide (HED-NCM) is a state-of-art positive electrode material which achieves a high specific capacity (~250 mAh/g). Overall cycling life is limited by electrode degradation, stemming mainly from oxygen release as well as transition metal dissolution. To mitigate the latter problem, a thin layer of aluminum oxide (Al2O­3­) can be applied to the active material by atomic layer deposition (ALD) to form an artificial cathode-electrolyte interphase (CEI). Testing has shown that the Al2O3 coating improves overall reversible capacity, most notably at high temperature (40oC). However, effect of the Al2O3 on the CEI and SEI formed upon cycling has yet to be understood. The cycling performance and surface chemistry Al2O3 coated HED-NCM materials cycled at room temperature and 40°C were investigated via ATR-FT-IR and XPS spectroscopies, and ICP-MS after the first and 50th cycles. Overall, electrodes made with Al2O3 coated material had lower concentrations of polyethylene carbonate and fluorine species, and Al2O­3­ coating helps in preventing transition metal dissolution.