MgO As a Water Scavenger in Lithium-Ion Batteries' Separators

In lithium-Ion batteries, multifunctional separators are able to improve performance and energy storage depending on the additives used to synthesize the separator layers. This study explores the possibilities of adding Magnesium Oxide (MgO) to lithium-ion batteries’ separators to act as a water scavenger. It was hypothesized that MgO, a ceramic nanoparticle, would bind to water molecules which prevents them from corroding the battery by reacting with the lithium-based electrolytes. A one-step fabrication method, namely UV-initiated polymerization-induced phase separation (PIPS), was used to fabricate microporous separator layers. As a base, Polyethylene Glycol Diacrylate (PEGADA 400), Ethylene Carbonate (EC), and a choice of photoinitiator were mixed, then varying amounts of MgO were added to the solution. MgO had shown that it does not interfere with the curing process of the layers, as well as an ability to remain trapped within the layers following the washing process. It had also shown to increase the porosity of the layer by 8.4% when 11.11% MgO is in the layer, however, lumping was observed in samples containing 20% MgO, decreasing porosity by -4.87%. Upon cycling a battery with a layer sample containing 11.11% MgO, the coulombic efficiency of the battery drops to 93.5% after 50 cycles, only 3.3% lower than a Celgard commercially sold separator layer sample. The voltage profiles, however, show that the capacity of the batteries were stable across the 50 cycles for both samples.