High Performance, Flexible, Solid‐State Supercapacitors Based on a Renewable and Biodegradable Mesoporous Cellulose Membrane

Abstract

A flexible, transparent, and renewable mesoporous cellulose membrane (mCel‐membrane) featuring uniform mesopores of ≈24.7 nm and high porosity of 71.78% is prepared via a facile and scalable solution‐phase inversion process. KOH‐saturated mCel‐membrane as a polymer electrolyte demonstrates a high electrolyte retention of 451.2 wt%, a high ionic conductivity of 0.325 S cm−1, and excellent mechanical flexibility and robustness. A solid‐state electric double layer capacitor (EDLC) using activated carbon as electrodes, the KOH‐saturated mCel‐membrane as a polymer electrolyte exhibits a high capacitance of 110 F g−1 at 1.0 A g−1, and long cycling life of 10 000 cycles with 84.7% capacitance retention. Moreover, a highly integrated planar‐type micro‐supercapacitor (MSC) can be facilely fabricated by directly depositing the electrode materials on the mCel‐membrane‐based polymer electrolyte without using complicated devices. The resulting MSC exhibits a high areal capacitance of 153.34 mF cm−2 and volumetric capacitance of 191.66 F cm−3 at 10 mV s−1, representing one of the highest values among all carbon‐based MSC devices. These findings suggest that the developed renewable, flexible, mesoporous cellulose membrane holds great promise in the practical applications of flexible, solid‐state, portable energy storage devices that are not limited to supercapacitors.

Superflexible Multifunctional Polyvinylpolydimethylsiloxane‐Based Aerogels as Efficient Absorbents, Thermal Superinsulators, and Strain Sensors

“…The aerogels have ad oubly crosslinked organic-inorganic network structure consisting of flexible polydimethylsiloxanes and hydrocarbon chains with tunable cross-linking density,t unable pore sizea nd bulk density.T hey have ah igh hydrophobicity and superflexibility and combine selective absorption, efficient separation of oil and water,thermal superinsulation, and strain sensing.Materials for environmental protection, energy saving,and smart sensing are increasingly needed to meet the growing social demands for sustainable development. [1][2][3][4] Porous materials including aerogels, [5,6] macroporous monoliths, [7] hydrogels, [8] polymer and carbon foams, [9] supramolecular gels, [10] metal-organic frameworks (MOFs), [11] and periodic mesoporous materials [12] have drawn alot of interest for their wide range of applications,s uch as in thermal insulation, oil removal, energy storage,sensing,catalysis and drug delivery. In particular, much attention has been paid to aerogels owing to their unique properties,such as high porosity,high specific surface area (SSA), low density,a nd low thermal conductivity.…”

Crosslinked quaternized poly(arylene ether sulfone) copolymer membrane applied in an electric double‐layer capacitor for high energy density

“…Therefore, the supercapacitor EDLC‐N‐0.2 assembled with c‐PAES‐N‐0.2 exhibited an appropriate specific capacitance value. With the neutral aqueous electrolyte system, E cell of EDLC‐N‐0.2 reached 8.20 W h/kg; this was much higher than that of the EDLCs with a KOH aqueous electrolyte system . The C s , energy densities, and power densities of EDLC‐N and EDLC‐N‐ x at a current density of 1.0 A/g are all listed in Table , and the energy density of each EDLC was higher than 7.0 W h/kg because of the wide potential window provided by the Li 2 SO 4 electrolyte and the high σs of the PAES copolymer membranes.…”

Multi‐walled carbon nanotubes incorporation into cross‐linked novel alkaline ion‐exchange membrane for high efficiency all‐solid‐state supercapacitors

“…To examine the microstructure of the as‐prepared MWCNTs‐CP‐OH − composite membranes, cross‐section scanning electron microscopy (SEM) images of the as‐prepared MWCNTs‐CP‐OH − membranes were obtained and are presented in Figure . It is observed from Figure 2A‐C that with and without MWCNTs, all of the MWCNTs‐CP‐OH − membranes exhibit a three‐dimensional (3D) porous internal architecture that accelerates the movement of charge carriers and leads to high OH − conductivity . The unique 3D porous architecture can also enhance the mechanical properties of the MWCNTs‐CP‐OH − membranes.…”

“…It is observed from Figure 2A-C that with and without MWCNTs, all of the MWCNTs-CP-OH − membranes exhibit a three-dimensional (3D) porous internal architecture that accelerates the movement of charge carriers and leads to high OH − conductivity. [51][52][53] The unique 3D porous architecture can also enhance the mechanical properties of the MWCNTs-CP-OH − membranes. It should also be noted that the original structure of the MWCNTs-CP-OH − composite membranes does not change but became more hierarchical owing to the modifications by the MWCNTs' filler ( Figures 2B,C).…”