Device level reversible potassium intercalation into bilayer graphene

Abstract

Electrochemical intercalation and storage of alkali metal ions into the graphite interlayer space is a key ingredient for commercial rechargeable ion batteries. While this has been exceptionally fruitful for lithium, the use of other more abundant chemical species such as potassium has fallen behind due to their less favorable ionic radius and host-guest interactions. Here, we deploy a device level on-chip cell architecture to study the reversible intercalation of potassium into the single van der Waals gallery of a graphene bilayer at room temperature and monitor in a time-dependent manner the electronic properties of the graphene bilayer during the insertion and extraction processes. The potassium diffusion is highly reversible and a charge transfer up to about 2.5×1013 cm-2 is achieved. The diffusion coefficient well exceeds 10-7 cm2 s-1 at room temperature, an order of magnitude larger than previously reported values in graphite and other compounds.

Synergistic Effects of Carbon Vacancies in Conjunction with Phosphorus Dopant across Bilayer Graphene for the Enhanced Hydrogen Evolution Reaction

“…Bilayer graphene also holds promising applications in the field of energy storage and is anticipated to emerge as a favorable electrode material for secondary batteries. − Several studies on the fundamental properties of doped bilayer graphene have been reported previously. − Besides, bilayer graphene codoped with FeN 4 –HfN 4 and FeN 4 –IrN 4 has been reported for its remarkable catalytic prowess in the realms of HER, OER, and ORR . The bilayer heterojunction composed of CoN 4 -embedded graphene and B-doped graphene has been documented to exhibit outstanding oxygen reduction electrocatalytic activity .…”