Gupta Ravindra Kumar, Imran Ahamad, Khan Aslam
King Abdullah Institute for Nanotechnology, King Saud University, Riyadh 11451, Saudi Arabia.
Polymers (Basel). 2024 May 19;16(10):1436. doi: 10.3390/polym16101436.
In a solid-state dye-sensitized solar cell, a fast-ion conducting (σ > 10 S cm) solid redox mediator (SRM; electrolyte) helps in fast dye regeneration and back-electron transfer inhibition. In this work, we synthesized solid Co redox mediators using a [(1 - )succinonitrile: poly(ethylene oxide)] matrix, LiX, Co(tris-2,2'-bipyridine)(bis(trifluoromethyl) sulfonylimide), and Co(tris-2,2'-bipyridine)(bis(trifluoromethyl) sulfonylimide) via the solution-cast method, and the results were compared with those of their acetonitrile-based liquid counterparts. The notation is a weight fraction (=0, 0.5, and 1), and X represents an anion. The anion was either bis(trifluoromethyl) sulfonylimide [TFSI; ionic size, 0.79 nm] or trifluoromethanesulfonate [Triflate; ionic size, 0.44 nm]. The delocalized electrons and a low value of lattice energy for the anions made the lithium salts highly dissociable in the matrix. The electrolytes exhibited σ ≈ 2.1 × 10 (1.5 × 10), 7.2 × 10 (3.1 × 10), and 9.7 × 10 (6.3 × 10) S cm for = 0, 0.5, and 1, respectively, with X = TFSI (Triflate) ions. The log σ- plot portrayed a linear curve for = 0 and 1, and a downward curve for = 0.5. The electrical transport study showed σ(TFSI) > σ(Triflate), with lower activation energy for TFSI ions. The anionic effect increased from = 0 to 1. This effect was explained using conventional techniques, such as Fourier transform infrared spectroscopy (FT-IR), X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), UV-visible spectroscopy (UV-vis), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA).
在固态染料敏化太阳能电池中，一种快速离子传导（σ>10 S cm）的固体氧化还原介质（SRM；电解质）有助于实现快速的染料再生并抑制背电子转移。在本工作中，我们通过溶液浇铸法，使用[(1 - )丁二腈：聚环氧乙烷]基质、LiX、Co(三(2,2'-联吡啶))(双(三氟甲基)磺酰亚胺)以及Co(三(2,2'-联吡啶))(双(三氟甲基)磺酰亚胺)合成了固体Co氧化还原介质，并将结果与其基于乙腈的液体对应物进行了比较。符号 为重量分数（=0、0.5和1），X代表一种阴离子。该阴离子要么是双(三氟甲基)磺酰亚胺[TFSI；离子尺寸，0.79 nm]，要么是三氟甲磺酸盐[三氟甲磺酸盐；离子尺寸，0.44 nm]。阴离子的离域电子和较低的晶格能值使得锂盐在基质中高度可解离。对于X = TFSI（三氟甲磺酸盐）离子，当 = 0、0.5和1时，电解质的电导率分别约为2.1×10 (1.5×10)、7.2×10 (3.1×10)和9.7×10 (6.3×10) S cm。log σ- 图对于 = 0和1呈现线性曲线，对于 = 0.5呈现向下曲线。电输运研究表明σ(TFSI)>σ(三氟甲磺酸盐)，TFSI离子的活化能更低。阴离子效应从 = 0增加到1。使用傅里叶变换红外光谱（FT - IR）、X射线衍射（XRD）、X射线光电子能谱（XPS）、扫描电子显微镜（SEM）、紫外可见光谱（UV - vis）、差示扫描量热法（DSC）和热重分析（TGA）等传统技术对这种效应进行了解释。
