Mixed Polyanion Glass Cathodes: Mixed Alkali Effect

Journal Article · Sun Jan 01 00:00:00 EST 2017 · Journal of the Electrochemical Society

DOI:https://doi.org/10.1149/2.1881712jes· OSTI ID:1399383

Kercher, A. K.; Chapel, A. S.; Kolopus, J. A.; Boatner, L. A.

In lithium-ion batteries, mixed polyanion glass cathodes have demonstrated high capacities (200-500 mAh/g) by undergoing conversion and intercalation reactions. Mixed polyanion glasses typically have the same fundamental issues as other conversion cathodes, i.e.: large hysteresis, capacity fade, and 1st-cycle irreversible loss. A key advantage of glass cathodes is the ability to tailor their composition to optimize the desired physical properties and electrochemical performance. The strong dependence of glass physical properties (e.g., ionic diffusivity, electrical conductivity, and chemical durability) on the composition of alkali mixtures in a glass is well known and has been named the mixed alkali effect. The mixed alkali effect on battery electrochemical properties is reported here for the first time. Depending on glass composition, the mixed alkali effect is shown to improve capacity retention during cycling (from 39% to 50% after 50 cycle test), to reduce the 1st-cycle irreversible loss (from 41% to 22%), and improve the high power (500 mA/g) capacity (from 50% to 67% of slow discharge capacity).

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Vehicle Technologies Office (EE-3V)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1399383
• Journal Information: Journal of the Electrochemical Society, Vol. 164, Issue 12; ISSN 0013-4651
• Publisher: The Electrochemical Society
• Country of Publication: United States
• Language: English