2, Vanderbilt University, Nashville, Tennessee, United States
3, Vanderbilt University, Nashville, Tennessee, United States
A critical bottleneck in the development of a high power battery material is to overcome the rate-limiting de-solvation step associated with intercalation of an alkali ion into graphite. Here, I will discuss results focused on utilizing co-intercalation as a method to enable fast charging and high power batteries. This concept pivots on the strong interaction between linear ether solvent molecules and alkali metal ions that results in a solvent shell which chelates the metal ion. This strong interaction leads the ion to maintain its solvent shell through insertion and extraction from graphite, bypassing the normal rate-limiting kinetics associated with desolvation. I will specifically discuss high-rate potassium and sodium co-intercalation into natural graphite that exhibits specific capacities above 100 mAhg-1 at currents of 5 Ag-1. To pair this into a full-cell battery architecture, I will discuss cathode options including Prussian blue nanoparticles that exhibit similar capacities at rates up to 10 C. The results from this work demonstrates how cointercalation of alkali ions poses an exciting option for high power batteries that rely on strategies where moderate energy density and low-cost make them an excellent option for emerging areas of grid storage, electric vehicles, and other high-power applications.