X.Y. Shi, L.J. Tian, S. Wang, P.C. Wen, M. Sub, H. Xiao, P. Das, F. Zhou, Z.P. Liu, C.L. Sun, Z.-S. Wu*, X.H. Bao

Journal of Energy Chemistry, 2021, 52, 284-290.

DOI: 10.1016/j.jechem.2020.04.064 [PDF]

Microscale electrochemical energy storage devices, e.g., micro-supercapacitors (MSCs), possessing tailored performance and diversified form factors of lightweight, miniaturization, flexibility and exceptional integration are highly necessary for the smart power sources-unitized electronics. Despite the great progress, the fabrication of MSCs combining high integration with high volumetric performance remains largely unsolved. Herein, we develop a simple, fast and scalable strategy to fabricate graphene based highly integrated MSCs by a new effective continuous centrifugal coating technique. Notably, the resulting highly conductive graphene films can act as not only patterned microelectrodes but also metal-free current collectors and interconnects, endowing modular MSCs with high integrity, remarkable flexibility, tailored voltage and capacitance output, and outstanding performance uniformity. More importantly, the strong centrifugal force and shear force generated in continuous centrifugal coating process lead to graphene films with high alignment, compactness and packing density, contributing to excellent volumetric capacitance of ~31.8 F cm⁻³and volumetric energy density of ~2.8 mWh cm⁻³, exceeding most reported integrated MSCs. Therefore, our work paves a novel way for simple and scalable fabrication of integrated MSCs and offers promising opportunities as standalone microscale power sources for new-generation electronics.