Poly(ionic liquid) Bridge Joining Smectic Lamellar Conducting Channels in Photoelectrochemical Devices as High-Performance Solid-State Electrolytes

Abstract

Nanostructured ionic liquid crystals have emerged as promising electrolytes with the potential to satisfy the demands of both efficient charge transport and stability over conventional liquid electrolytes for advanced energy devices. However, traditional methods via the macroscopic orientation of ionic liquid crystals for charge transport intensification can hardly be achieved during practical device applications. Herein, a simple method was proposed to spontaneously construct long-range continuous conducting channels for significantly improving the charge transport of ionic liquid crystals in the confined space of energy devices. A poly(imidazolium ionic liquid) was designed and in situ prepared in a smectic [C 14 MIm][I]-based electrolyte for photoelectrochemical device fabrication. The composite solid-state electrolyte self-assembled microphase-segregation nanostructures, wherein the poly(ionic liquid) aggregated at the boundaries of layered smectic polydomains. The imidazolium iodide ions in the poly(ionic liquid) acted as imbedded ion tunnels at domain interfaces via π−π stacking and ionic interaction, which facilitated the charge transport crossing the interfacial gaps to join the intradomain lamellar channels as thermally stable and long-range continuous charge transport pathways. By using the poly(ionic liquid) to bridge the domain-interfacial gaps, the ion conductivity of the ionic liquid crystals was up to 7 times increased with a maximum value of 2.0 × 10 −3 S cm −1 , and the derived dye-sensitized solar cell could operate stably at 70 °C with a 2-times enhancement and champion efficiency of 8.2%. The approach here was comparable but more processable to traditional methods via the macroscopical orientation of ionic liquid crystals for charge transport intensification within energy devices, which have great potential to develop high-performance solid-state electrolytes to achieve the best balance between efficiency and durability for energy devices.

Remarkable 8.3% efficiency and extended electron lifetime towards highly stable semi-transparent iodine-free DSSCs by mitigating the in-situ triiodide generation

“…Concerning the addition of EC, we opted for the most concentrated PIL, the PS3 which is rich in Ias the addition of solvent reduces the ionic concentration. Furthermore, for this type of electrolyte, good photovoltaic performances are associated with the creation of ionic/non-ionic phaseseparated domains that favor I − percolation and rapid diffusion [78,79]. As shown in Fig.…”

Polymerized and Colloidal Ionic Liquids─Syntheses and Applications

“…Tan et al prepared a composite solid-state electrolyte by self-assembly of microphase-segregation nanostructures, accompanied by an aggregated PIL at the boundaries of layered smectic polydomains. 721 The imidazolium iodide ions were embedded in the PIL and formed ion tunnels via π−π stacking and ionic interaction, which facilitated the charge transport at domain interfacial gaps between intradomain lamellar channels and long-range continuous charge transport pathways. With the assistance of this PIL helping to bridge domain-interfacial gaps, it showed a high ion conductivity of 2.0 × 10 −3 S cm −1 , and its self-assembled DSSC exhibited a very significant efficiency of 8.2% at 70 °C.…”

“…Nanostructured ionic liquid crystals having long-range continuous conducting channels can greatly improve the charge transport of ions in ILs and in PILs. Tan et al prepared a composite solid-state electrolyte by self-assembly of microphase-segregation nanostructures, accompanied by an aggregated PIL at the boundaries of layered smectic polydomains . The imidazolium iodide ions were embedded in the PIL and formed ion tunnels via π–π stacking and ionic interaction, which facilitated the charge transport at domain interfacial gaps between intradomain lamellar channels and long-range continuous charge transport pathways.…”

Printability of (Quasi-)Solid Polysiloxane Electrolytes for Online Dye-Sensitized Solar Cell Fabrication

“…Thermosetting gel electrolytes are prepared by soaking the synthesized copolymer in liquid electrolyte followed by thermo- [101][102][103][104] or photopolymerization [105][106][107] in situ. Table S1 in Supplementary Materials summarizes the latest achievements of thermosetting polymer electrolytes use in DSSCs.…”