Mechanism of potassium ion intercalation staging in few layered graphene from Raman spectroscopy

• Published in: Nanoscale 2016-09, Vol.8 (36), p.16435-16439
• Main Authors: Share, Keith, Cohn, Adam P, Carter, Rachel E, Pint, Cary L
• Format: Article
• ISSN: 2040-3364; 2040-3372
• DOI: 10.1039/c6nr04084e

Recently emerging potassium ion (K-ion) batteries offer a lower-cost alternative to lithium-ion batteries while enabling comparably high storage capacity. Here, we leverage the strong Raman spectroscopic response of few-layered graphene to provide the first insight into the electrochemical staging sequence for K + ions in graphitic carbons. Our analysis reveals the signature of a dilute stage I compound that precedes formation of ordered intercalation compounds transitioning from stage VI (KC 72 ), stage II (KC 24 ), and stage I (KC 8 ) and correlates electrochemical responses to the stage formation. Overall, our study emphasizes a minimum barrier to transfer the general understanding acquired for lithium-ion battery anodes to cheaper, earth abundant K-ion battery systems ideally suited for grid-scale storage. Recently emerging potassium ion (K-ion) batteries offer a lower-cost alternative to lithium-ion batteries while enabling comparably high storage capacity.