Giant tunability of interlayer friction in graphite via ion intercalation

Abstract Two dimensional (2D) materials have attracted great interest due to their unique structures and properties. However, the loss of the exceptional properties of 2D constituents in their 3D counterparts poses a grand challenge to the widespread use of 2D materials. How to achieve comparable superior properties in 3D materials made of 2D constituents still remains elusive. Here we demonstrate an effective approach to tailoring the mechanical properties 3D materials made of 2D constituents via ion intercalation. We show that, by intercalating Li ions into graphite, the inter-graphene-layer friction can be drastically increased up to 7 times of that in natural graphite. We attribute the drastic increase of inter-graphene-layer friction to the electrostatic interaction of graphene layers with the intercalants. The layered structure of 2D materials and the weak inter-layer interactions allow for facile intercalation of various foreign species into the vdW gap of 2D materials. Therefore, fertile opportunities exist to leverage ion intercalation to fine tune the interlayer interaction between 2D constituents, paving a promising way to programmable mechanical properties of their 3D counterpart materials.