2, Vanderbilt University, Nashville, Tennessee, United States
3, Binghamton University, State University of New York, Binghamton, New York, United States
Co-intercalation chemistry using sodium and potassium ions enable charge storage in graphite electrodes for alternative-ion battery chemistries. Using linear ether solvents (glymes) allows for reversible insertion and de-insertion of alkali ions coordinated by a glyme molecule into graphite electrodes. This unique chemistry boasts increased ion diffusivity in graphitic carbons while generating a large volume expansion (>250%). These unique features allow exploitation of this co-intercalation chemistry in systems ranging from low-power nano- and micro- actuators and energy harvesters to high rate batteries (>10 C with energy densities ~100 Wh/kg), which rival commercial supercapacitors. These results prove the viability of alternative-ion co-intercalation based batteries for use in low-cost, high-power applications.