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 (Al₂O_­3­) 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 (40^oC). 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 50^th cycles. Overall, electrodes made with Al₂O₃ coated material had lower concentrations of polyethylene carbonate and fluorine species, and Al₂O_­3­ coating helps in preventing transition metal dissolution.