Durable potassium ion battery electrodes from high-rate cointercalation into graphitic carbons

摘要: We report the first demonstration of potassium ion cointercalation into graphitic carbon electrodes including both natural graphite and multi-layered graphene in diglyme monoglyme based electrolytes. Contrary to conventional desolvation-based intercalation potassium, we demonstrate excellent capacity retention ∼80% at rates up 10 A g−1 (30 second charge), with 95% over 1000 cycles, 100 mA h capacity. Raman X-ray diffraction following cycles demonstrates no signature defects, damage, or change crystallinity compared uncycled pristine materials that is attributed weak ion–lattice interactions due solvated guest K ions. In situ spectroscopy highlights sequential formation a stage 4, 3, 2, 1 compound (GIC) occurs without dilute staging. charged compound, observe lattice expansion from 0.335 nm 1.16 measure work function be ∼3.4 eV. Overall, this system overcomes rate durability bottlenecks limit current K-ion battery electrodes, gives promise for durable, fast, low-cost storage systems.