The next generation of batteries may employ ionic liquid electrolytes with stability windows of more than 6 volts, and migrate from lithium ion chemistries to more earth-abundant cations such as sodium, potassium, or magnesium ions. In this work we revisit known lithium ion battery cathode materials to gain insight into requisite properties for next-generation batteries, with particular emphasis on spinel lithium manganese oxide (LiMn2O4). LiMn2O4 is a common cathode material for lithium ion batteries, with a very fast charge-discharge rate. We synthesize LiMn2O4 by atomic layer deposition of MnO followed by electrochemical treatment. The precise thickness control of the ALD-grown MnO films allows for the study of charge storage size effects in LiMn2O4. We evaluate the charge storage properties of LiMn2O4 in aqueous Li+, Na+, K+, and Mg2+ electrolytes to determine the viability of spinel MnO2 as a cathode material for these cations. Additionally, we employ periodic quantum mechanical calculations to theoretically evaluate the charge storage properties of spinel MnO2 with intercalated Li+, Na+, K+, and Mg2+ within an electronic structure and band diagram framework. In general, the work function and electronic structure of a cation host material determine the equilibrium potential(s) for charge-transfer in the intercalated compound.

Guiding principles for next-generation batteries from theoretical and experimental studies of LiMn2O4

249th National Meeting (2015)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.