Enhanced performance of supercapacitors based on rotationally stacked CVD graphene

Abstract

One of the main problems faced by 2D materials used in supercapacitor applications when scaling up is restacking, such that their gravimetric capacitances become dramatically inferior to that of their monolayer forms. This study analyzes the Raman spectra of transferred layers of CVD-graphene revealing decoupling and rotational stacking of layers, with the potential of retention of intrinsic monolayer properties. Rotationally stacked layers have the potential to mitigate restacking and, thus, are capable of easing ion intercalation and boosting their performance in supercapacitor applications. In this pursuit, binder-free supercapacitors are fabricated out of chemical vapor deposited bilayer graphene, successively transferred to form rotationally stacked multilayers. Supercapacitors constructed with rotationally stacked four-layer graphene have an incredible specific gravimetric capacitance of 316.1F g(-1) at 1 mVs(-1), with a corresponding energy density of 28.1 Wh kg(-1) and similar to 100% capacitance retention at 10000 cycles. Published under an exclusive license by AIP Publishing.