Figure 2.13 An electrochromic device containing DNA‐based electrolyte.
Source: Tihan et al. [135].
2.4 Conclusion and Future Outlook
The field of PE is steadily broadening, as more and more various application are presented. Although lithium‐ion‐based electrolytes have been commercialized, such as applied in pull down window shades on Boeing 787 Dreamliner, smart glass in Ferrari 575 M Superamerica, and Flexity 2 light rail vehicles, some disadvantages such as poor safety, easy leakage, and unstable electrochemical performance limit its further development and wider applications. In this chapter, we have provided fundamental understanding of requirements for EC applications. In the meantime, recent progresses on polymer‐based electrolytes were summarized, including PEO/PVDF/PMMA gel polymer, self‐healing polymer, cross‐linking polymer, ceramic polymer, IL polymer, and gelatin PEs. The use of composite PEs has been identified as a promising method to improve the performance of electrolytes.
Table 2.1 Polymer hosts generally studied with the examples of gel polymer electrolyte complexes and their respective highest ionic conductivities.
| Polymer electrolyte | EC materials | Ionic conductivity (S/cm) | Electrochemical stability window (V) | Optical modulation (%) | Stability | References |
|---|---|---|---|---|---|---|
| p(trimethylenecarbonate [TMC])/PEO | Prussian Blue/PEDOT | 1.33 × 10−6 | −1.5 ∼ 1 | 8 ∼ 30 | Full color switch (>600 s) | [138] |
| PEO/PVDF | TiO2 | 6.98 × 10−6 | — | 90 | — | [15] |
| PEO/LiClO4 | PEDOT:PSS | 4.2 × 10−4 | −3.0 ∼ 3.0 | 22 | No significant change | [139] |
| P(VDF‐TrFE)/PEO | PEDOT:PSS | 6.79 × 10−4 | −1.0 ∼ 0.5 | 60 | — | [140] |
| PEMA/poly (vinylidene fluoride) (PVdF)‐HFP | WO3//CeO2–TiO2 | 1.46 × 10−6 | −1.3 ∼ −0.8 | 81 | — | [141] |
| PVdF‐HFP/silane‐functionalized ZrO2 | PANI:DBSA | 1.78 × 10−3 | −4.0 ∼ 4.0 | 70 | — | [142] |
| PVDF‐HFP/POEI‐ISF4 | Nanofibers | 8.62 × 10−3 | 0 ∼ 1.2 | 68.7 | 95.5% of ΔT | [143] |
| PVDF‐co‐HFP/[EMI][TFSI] | 1,1′‐bis(3‐fluoro‐4‐(trifluoromethyl)phenyl)‐4,4′‐bipyridinium bis(trifluoromethylsulfonyl)imide (TFMFPhV(TFSI)2) | 6.7 × 10−3 | −0.35 ∼ 0 | ∼73 | ∼14% decrease of ΔT after 24 h | [144] |
| IL/PVDF‐HFP | PEDOT:PSS | 1.13 × 10−3 | −1.4 ∼ 1.4 | ∼24 | — | [54] |
| TMPD/HV(BF4)2/SN/PVDF‐HFP | TMPD/HV(BF4)2/succinonitrile | 1 × 10−3 | 0 ∼ 0.9 | 60.1 | 74.7% of the original ΔT after 2000 cycles | [145] |
| [Emim]BF4/PMMA | WO3 | 2.9 × 10−3(RT) | −3.0 ∼ 1.5 | 88 | — | [146] |
| Poly(ether ether ketone) membrane | IR‐VEDs | 6.8 × 10−3 | −1.0 ∼ 1.0 | 47 | Good cycling stability | [147] |
| PVDF‐HFP:PMMA/LiClO4 | — | 2.83 × 10−4 | — | — | — | [148] |
| PMMA/SN‐PC | WO3//brain natriuretic peptide (PBNPs) | 1.46 × 10−3 | −2.5 ∼ 2.0 | 52.4 | 44.5% after 2250 cycles | [149] |
| Poly(ε‐caprolactone) (PCL)/SiO2 | PEDOT: PSS | 5.2 × 10−3 | −4.0 ∼ 1.0 | 30.6 | Good stability (100 cycles) | [150] |
| Polyvinyl butyral (PVB)‐based GPEFs | WO3//Ni1−xO | 4.0 × 10−5 | −2.0 ∼ 2.0 | 65.8 |
|