Ice-Templated Large-Scale Preparation of Two-Dimensional Sheets of Conjugated Polymers: Thickness-Independent Flexible Supercapacitance

Abstract

Two-dimensional (2D) organic materials hold great promise for use in a multitude of contemporary applications due to their outstanding chemical and physical properties. Herein, 2D sheets of poly­(3,4-ethylenedioxythiophene):poly­(4-styrenesulfonate) (PEDOT:PSS) are prepared from a commercially available PEDOT:PSS suspension using ice as a template. The 2D PEDOT:PSS sheets grow in the boundaries of ice crystals as the polymers are “squeezed” out of the suspension when the water solidifies. The mechanical robustness of the sheets can be enhanced by incorporating WO3 nanowires, and the PSS component can be conveniently removed with a concentrated solution of H2SO4 to afford stable suspensions of PEDOT or WO3@PEDOT sheets, either of which can be converted into flexible films with tunable thicknesses via filtration. Swagelok- or pouch-type supercapacitor devices prepared from the WO3@PEDOT films exhibit outstanding energy-storage characteristics, including high rate capability, thickness-independent energy storage (e.g., 701 mF cm–2 is achieved with a 1-mm-thick film), high resistance toward mechanical deformation, and good cycling stability. Additionally, a high energy density of 0.083 mWh cm–2 is measured for a device prepared using a 1-mm-thick film at a high power density of 10 mW cm–2. The methodology described establishes an efficient and readily scalable approach for accessing 2D organic sheets.

Agarose-Based Hierarchical Porous Carbons Prepared with Gas-Generating Activators and Used in High-Power Density Supercapacitors

“…g Value was obtained at a relative pressure of 0.35. charge transfer in the electrodes is relatively fast. 63 Figure 6b shows the discharge data as recorded at different current densities for supercapacitors prepared from PC-6-700. The linear characteristics of the discharge curves are consistent with the CV data and indicated that an electrochemical double-layer energy storage mechanism is operative.…”

“…The device exhibited CV curves with rectangular shapes, consistent with ideal electrochemical double-layer capacitance. The rectangular shape was retained at elevated scan rates which indicated that charge transfer in the electrodes is relatively fast Figure b shows the discharge data as recorded at different current densities for supercapacitors prepared from PC-6-700.…”

Advances in Emerging Photonic Memristive and Memristive‐Like Devices

“…[ 150 ] 2D materials have been applied in various applications since graphene is successfully prepared in 2009, such as lubricant, [ 151 , 152 , 153 ] triboelectric nanogenerator, [ 154 , 155 , 156 ] field effect transistor, [ 157 , 158 ] and wearable devices. [ 159 , 160 , 161 , 162 ] In particular, graphene serves as the channel materials to apply in the application of photoelectric detection in the year when it is successfully prepared, which proves that graphene has the capability to be light sensitive. [ 163 , 164 ] This work provides a prelude to the applications of 2D materials in photonic devices.…”

Two-Dimensional Frank−Kasper Z Phase with One Unit-Cell Thickness

“…A diffuse scattering ring appears in the SAXS image recorded in the as-quenched sample indicates that no precipitates or clusters are present (Figure 2a). 32,33 The diffuse scattering signal rises in Figure 2b suggests clearly that some nanoscale phases have formed when aging up to 48 h. This scattering appears to be mostly isotropic, although some faint anisotropy is observable. The scattering signal significantly increases when the alloy is aged up to 100 h, and it exhibits more streaks oriented in random directions (Figure 2c Bright-filed TEM images, and corresponding SAED patterns are provided in Supporting Information, Figure S3.…”

“…The upper-right insets in Figure a–c show raw 2D small-angle X-ray scattering (SAXS) images of the Mg–4Sm–2Zn alloy, from the initially quenched state up to 100 h aged at 200 °C. A diffuse scattering ring appears in the SAXS image recorded in the as-quenched sample indicates that no precipitates or clusters are present (Figure a). , The diffuse scattering signal rises in Figure b suggests clearly that some nanoscale phases have formed when aging up to 48 h. This scattering appears to be mostly isotropic, although some faint anisotropy is observable. The scattering signal significantly increases when the alloy is aged up to 100 h, and it exhibits more streaks oriented in random directions (Figure c, as the red arrows indicated), corresponding to the scattering of precipitates within arbitrarily oriented grains.…”