Polyurethane films based on renewable sources were prepared as an alternative to petroleum‐based polyurethane. The effects of the structure and ratio of diisocyanate components on polymer properties were investigated. Hexamethylene diisocyanate (HMDI) and diphenylmethylene diisocyanate (MDI) were chosen as the diisocyanate components in polymer synthesis. Membranes were prepared by casting‐evaporation technique and characterized for their gas permeability, film and mechanical properties. The oil‐based membranes were found to be suitable for wound dressing applications.

In this work, to construct a sunlight-powered energy storage system, single wall carbon nanotubes (SWCNTs)-based symmetric micro-supercapacitors (MSCs) were fabricated by a one-step, facile spraying method. The electrodes exhibited satisfactory conductivity with a sheet resistance of 275 Ω/sq. Moreover, potassium hydroxide-poly(vinyl alcohol) (KOH-PVA) and phosphoric acid-nonionic surfactant liquid crystal (PA-NI LC) gel electrolytes were prepared and applied to design all-solid-state MSC devices. Compared to the device assembled using the SWCNTs/KOH-PVA gel electrolyte, the SWCNTs/PA-NI LC electrolyte displayed larger areal capacitance with the largest recorded value of 11.0 mF•cm −2 at a current density of 0.08 mA• cm −2 at room temperature. Additionally, the effect of temperature on the MSC device performance was assessed, and the results revealed that the device based on the SWCNTs/PA-NI LC electrolyte achieved enhanced electrochemical performance at an operating temperature of 65 °C, including a large areal capacitance of 14.7 mF•cm −2 at 0.08 mA•cm −2 , a better rate performance of 88% with 12.9 mF•cm −2 at 0.4 mA•cm −2 , and a higher energy density of 2.04 μWh•cm −2 at a power density of 40.64 μW•cm −2 . In addition, the MSC device featured high cyclic stability under bending conditions (45 or 90°) at room temperature. Furthermore, a sunlight-powered energy storage system was fabricated, combining solar cells with the as-assembled MSC devices. Three MSCs connected in series were charged by solar cells and further acted as the energy supply for a red light-emitting diode (LED), which could be continuously operated for 2 min 30 s. All of the findings herein represent a good indication of the promising practical application potential of the as-prepared MSC devices as energy storage devices at high temperatures.

Summary Proton‐conducting gel electrolytes offer significant advantages for supercapacitors. Among various acids, phosphoric acid (H3PO4·H2O, PA) has the highest proton conductivity for use as a supercapacitor electrolyte. Compared with commonly used acidic and basic electrolytes (H2SO4 and KOH), a high specific capacitance of approximately 620 F g−1 was attained for PA under 0.1 A g−1 test conditions in combination with a reduced graphene oxide (rGO) symmetric electrode. Moreover, the PA electrolyte was further improved by confining it to a liquid crystal (LC) gel matrix. PA and a non‐ionic surfactant (lauryl ether, C12H25[OCH2CH2]10OH) were used to form LC gels with PA:NI mole ratios 60 to 100:1, which had viscosity values in 800 to 5500 mPa s−1 range at a shear rate of 100 s−1 and provided a high gravimetric specific capacitance of approximately 1128 F g−1 when tested at 0.1 A g−1 with an rGO symmetric electrode. The mesophase of the LC gel at each PA:NI mole ratio was comprehensively analyzed using X‐ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR), and polarized optical microscopy (POM) to confirm that the mesostructure was responsible for the high specific capacitance. The electrochemical performance was studied using electrochemical methods and galvonastatic charge/discharge tests. Furthermore, to increase the energy density of supercapacitors, focusing on automotive applications, this LC gel electrolyte could be used in an asymmetrical pseudocapacitor design.