Sand-Milling Fabrication of Screen-Printable Graphene Composite Inks for High-Performance Planar Micro-Supercapacitors

Abstract

Rational engineering and simplified production of printable graphene inks are essential for building high-energy and flexible graphene micro-supercapacitors (MSCs). However, few graphene-based MSCs show impressive areal capacitance and energy density, especially based on additive-manufacturing, cost-effective, and printable inks. Herein, a newstyle and solution-processable graphene composite ink is ingeniously formulated for scalable screen printing MSCs. More importantly, the asformulated inks consist of interwoven two-dimensional graphene and activated carbon nanofillers, which are delaminated by one-step sandmilling turbulent flow exfoliation. Notably, embedding the activated carbon nanoplatelets into graphene layers drastically boosts the electrochemical performance of screen-printed micro-supercapacitors (denoted as Gr/AC-MSCs), such as an outstanding areal capacitance of 12.5 mF cm −2 (about 20 times than pure graphene). The maximum energy density, maximum power density, and exceptional cyclability are 1.07 μW h cm −2 , 0.004 mW cm −2 , and 88.1% after 5000 cycles, respectively. As such, the as-printed MSCs on paper display high resolution and pronounced energy-storage performance. Furthermore, the packaged and optimized Gr/AC-MSCs showcase remarkable mechanical flexibility even under highly folded and excellent water resistance, maintaining 91.8% capacitance retention after being washed for 90 min. The versatile methodology highlights the promise of graphene and analogous 2D nanosheet functional inks for scalable fabrication of flexible energy-storage devices.

All-Printed Paper-Based Micro-supercapacitors Using Water-Based Additive-Free Oxidized Single-Walled Carbon Nanotube Pastes

“…Consequently, electrochemically stable and conductive materials are employed in the preparation of all-printed MSCs. Graphene, MXenes, and nanoporous carbons are used to prepare printable conductive pastes and gels. ,− However, numerous inactive additives, binders, and conductive auxiliaries should be added to prepare printable pastes and gels composed of active materials.…”

Rational Formulation of Graphene Nanocomposite Ink for 2D Mutually Embedded Structure Interdigital Microsupercapacitors

“…The areal capacitance gradually decreases (from 16.1 to 4.54 mF cm –2 for MSC with ⟨ N ⟩ = 8) as the current density increases to 0.5 mA cm –2 (as shown in Figures f and S15), probably due to the intrinsic dissatisfactory rate capability of MnO 2 . The screen-printed Gr/MnO 2 -1 MSCs showcase superior electrochemical performance compared to other reported graphene (or hybrid) systems (Figure g and Table S1, Supporting Information), ,,,,,− particularly in the printed flexible and current collector-free graphene MSCs. Also, the relationship of areal and volumetric capacitances with various current densities is displayed in Figure S16.…”

Biocompatible Parylene-C Laser-Induced Graphene Electrodes for Microsupercapacitor Applications

“…However, LIG-MSCs were produced by a one-step approach by a potentially scalable method. In comparison with other techniques, such as printing , and stamping, , LIG does not require complicated multistep processes. In addition, as a digital method, it is quite simple to change the device format or architecture by laser engraving.…”