An iodine-free electrolyte based on ionic liquid polymers for all-solid-state dye-sensitized solar cells

An ionic liquid polymer, poly (1-alkyl-3-(acryloyloxy)hexylimidazolium iodide), was employed as an iodine-free electrolyte in all-solid-state dye-sensitized solar cells with an overall conversion efficiency of 5.29% under AM 1.5 simulated solar light (100 mW cm(-2)) illumination.     

Dye-sensitized TiO2 Solid Solar Cell Using Poly （4-vinylphenyloxy-methyltriphenylamine） as Hole Transport Material

A dye-sensitized TiO2 solid solar cell, which contains poly(4-vinylphenyloxy-methyltriphenylamine) in hole transport layer (HTL) doped with LiSCN and methyl-hexyl-imidazolium iodide (MHImI), was oreoared. The solar cell shows that the conversion efficiency is 0.59%, Jsc is 3.03mA/cm^2, and Voc is 0.53V at 1 sun light intensity.     

聚乙烯吡咯烷酮基碘凝胶电解质的制备及在染料敏化太阳能电池中的应用

采用聚乙烯吡咯烷酮(PVP)和聚偏氟乙烯(PVDF)为凝胶剂, 以碘化锂和碘单质为碘源, 碳酸乙烯酯(EC)和碳酸丙烯酯(PC)为溶剂, 制备了染料敏化太阳能电池(DSSCs)用凝胶聚合物电解质(GPE). 使用拉曼光谱、 循环伏安曲线和交流阻抗谱等对GPE进行表征. 结果表明, 聚合物的配比与浓度及碘与碘化锂比例对该电解质性能有很大影响, 当聚合物质量分数为10%、 PVP与PVDF质量比为80∶20、 I₂浓度为0.042 mol/L且LiI与I₂摩尔比为30∶1时, 制备的GPE在室温下电导率达最大值(3.27 mS/cm). 使用该GPE组装的DSSCs在100 mW/cm²的模拟太阳光照射下, 开路电压为0.64 V, 短路电流为13.6 mA/cm², 填充因子为0.595, 能量转化效率为5.18%, 并在30 d内表现出了良好的稳定工作性能.     

Quantum dot doped solid polymer electrolyte for device application

ZnS capped CdSe quantum dots embedded in PEO:KI:I₂ polymer electrolyte matrix have been synthesized and characterized for dye sensitized solar cell (DSSC) application. The complex impedance spectroscopy shows enhance in ionic conductivity (σ) due to charges provide by quantum dots (QD) while AFM affirm the uniform distribution of QD into polymer electrolyte matrix. Cyclic voltammetry revealed the possible interaction between polymer electrolyte, QD and iodide/iodine. The photovoltaic performances of the DSSC containing quantum dots doped polymer electrolyte was also found to improve.     

聚苯并咪唑-锂盐-聚乙二醇单甲醚共混全固态聚合物电解质的制备及性能

使用共混后浇铸成膜的方法,制备了聚苯并咪唑-锂盐-聚乙二醇单甲醚组成的锂离子电池共混全固态聚合物电解质。通过傅里叶红外光谱(FT-IR)、X射线衍射(XRD)、差示扫描量热(DSC)、拉伸与交流阻抗测试表征了共混全固态电解质的结构与性能。研究了不同锂盐以及各组分含量对共混全固态电解质的力学性能与电导率的影响。结果表明:聚苯并咪唑与聚乙二醇单甲醚之间存在氢键;共混全固态电解质中聚乙二醇单甲醚处于无定形态;锂盐的加入使聚乙二醇单甲醚的玻璃化转变温度下降;聚乙二醇单甲醚含量越高,共混膜强度越低,电导率越高,并且使用三氟甲磺酸锂作为锂盐时其电导率最高,室温下可以达到3.58×10~(-5) S/cm,高温下可以达到3.3×10~(-3) S/cm,高温下满足对锂离子电池的使用需求。     

Preparation of a novel polymer gel electrolyte based on N-methyl-quinoline iodide and its application in quasi-solid-state dye-sensitized solar cell

Using poly(acrylonitrile-co-styrene) as polymer host, 1,2-propanediol carbonate, dimethyl carbonate and ethylene carbonate as mixture solvent, N-methyl-quinoline iodide and iodine as the source of I⁻/I₃ ⁻, a novel polymer gel electrolyte with ionic conductivity of 5.12 × 10⁻³ S· cm⁻¹ at 25°C was prepared by sol-gel and hydrothermal methods. Based on the polymer gel electrolyte, a quasi-solid-state dye-sensitized solar cell was fabricated. The solar cell possess better long-term stability and light-to-electrical energy conversion efficiency of 4.04% under irradiation of 100 mW· cm⁻². The influences of polymer host, solvent, N-methyl-quinoline iodide and temperature on ionic conductivity of the polymer gel electrolyte and the performance of the dye-sensitized solar cell was discussed.     

染料敏化太阳电池用聚合物电解质

综述了本研究小组近年来用于染料敏化太阳电池中聚合物电解质的研究概况.设计合成了几类性能优良的聚合物电解质,较好地改进了液体电解质染料敏化太阳电池(DSSC)的使用稳定性,研究结果具有实际应用的价值,并提出了此领域研究今后的发展方向.     

Mg(OOCCH(3))(2) as an electrolyte additive for quasi-solid dye-sensitized solar cells: with the purpose of enhancing both the photovoltage and photocurrent by modifying the TiO(2)/dye/electrolyte interfaces

The interface modification effect within quasi-solid dye-sensitized solar cells and the photovoltaic performance were investigated after the introduction of Mg(OOCCH(3))(2) as an additive into a polymer gel electrolyte. Electrochemical impedance spectroscopy showed that the addition of Mg(OOCCH(3))(2) into the polymer gel electrolyte can efficiently retard charge recombination at the TiO(2)/electrolyte interface. Mg(OOCCH(3))(2) in the electrolyte can also contribute to the enhancement of the incident photon-to-electron conversion efficiency by modifying the dye molecules. This results in an improvement in the photovoltage and photocurrent due to a barrier layer at the TiO(2)/electrolyte interface and the promotion of charge injection at the dye/TiO(2) interface, respectively. Photovoltaic measurements reveal that a conversion efficiency enhancement from 4.05% to 4.96% under 100 mW cm(-2) is obtained after the amount of Mg(OOCCH(3))(2) added was optimized.     

Quasi-solid-state dye-sensitized solar cells assembled with polymeric ionic liquid and poly(3,4-ethylenedioxythiophene) counter electrode

Poly(3,4-ethylenedioxythiophene) nanofibers (PEDOT-NF) with high catalytic activity were synthesized and employed as a counter electrode in dye-sensitized solar cells (DSSCs). A polymeric ionic liquid (PIL) was used as a gelling agent and an iodide source for making a highly conductive gel polymer electrolyte. A quasi-solid-state DSSC assembled with this PIL-based gel polymer electrolyte and PEDOT-NF counter electrode exhibited high conversion efficiency of 8.12% at 100 mW cm^− 2.     

High efficiency dye-sensitized nanocrystalline solar cells based on ionic liquid polymer gel electrolyte

An ionic liquid polymer gel containing 1-methyl-3-propylimidazolium iodide (MPII) and poly(vinylidenefluoride-co-hexafluoropropylene) (PVDF-HFP) has been employed as quasi-solid-state electrolyte in dye-sensitized nanocrystalline TiO2 solar cells with an overall conversion efficiency of 5.3% at AM 1.5 illumination.     

Comprehensive studies on polymer electrolyte and dye-sensitized solar cell developed using castor oil-based polyurethane

Comprehensive characterization of new polymer electrolyte system prepared using polyurethane derived from castor oil polyol was undertaken. The castor oil polyol was synthesized via transesterification and reacted with 4,4′-diphenylmethane diisocyanate to form polyurethane. Polyurethane electrolyte films were prepared by addition of sodium iodide in different weight percentage with respect to the weight of the polymer. The electrolyte films were analyzed using Fourier transform infrared spectroscopy, dynamic mechanical analysis, electrochemical impedance spectroscopy, transference number measurement, and linear sweep voltammetry. Fourier transform infrared spectroscopy results confirmed the complexation between polymer and salt. Tan delta peak observed in the tan δ–temperature curve plotted using data obtained from dynamic mechanical analysis indicated that the glass transition temperature of polyurethane decreased with the addition of sodium iodide. The highest conductivity of 4.28 × 10^?7 S cm^?1 was achieved for the film with 30 wt% of sodium iodide. The performances of dye-sensitized solar cell using the electrolyte systems were analyzed in terms of short-circuit current density, open-circuit voltage, fill factor, and energy conversion efficiency. The polymer electrolyte with 30 wt% sodium iodide showed the best performance with energy conversion efficiency of 0.80%.     

改性LiClO_4－（PEO）_（20）电解质锂离子迁移数的测定

采用交流阻抗和恒电位计时电流法测定了ＬｉＣｌＯ４·（ＰＥＯ）２０·（ＰＣ）１２·（ＥＣ）１２高分子电解质的锂离子迁移数。在非水溶液和高分子电解质中,锂是热力学不稳定的,表面生成一层固体电解质钝化膜,严重地影响了锂离子迁移数的准确测定。本方法避免固体电解质钝化膜的影响,给出正确的锂离子迁移数测定值,实验表明,ＬｉＣｌＯ４·（ＰＥＯ）２０·（ＰＣ）１２·（ＥＣ）１２电解质的电导率为０．８×１０－３／ｃｍ,锂离子迁移数为０．３。     

Dependence of solar cell performance on the nature of alkaline counterion in gel polymer electrolytes containing binary iodides

Performance of dye-sensitized nano-crystalline TiO₂ thin film-based photo-electrochemical solar cells (PECSCs) containing gel polymer electrolytes is largely governed by the nature of the cation in the electrolyte. Dependence of the photovoltaic performance in these quasi-solid state PECSCs on the alkaline cation size has already been investigated for single cation iodide salt-based electrolytes. The present study reports the ionic conductivity dependence on the nature of alkaline cations (counterion) in a gel polymer electrolyte based on binary iodides. Polyacrylonitrile-based gel polymer electrolyte series containing binary iodide salts is prepared using one of the alkaline iodides (LiI, NaI, KI, RbI, and CsI) and tetrapropylammonium iodide (Pr₄NI). All the electrolytes based on binary salts have shown conductivity enhancement compared to their single cation counterparts. When combined with Pr₄NI, each of the Li⁺, Na⁺, K⁺, Rb⁺, and Cs⁺ cation containing iodide salts incorporated in the gel electrolytes has shown a room temperature conductivity enhancement of 85.59, 12.03, 12.71, 20.77, and 15.36%, respectively. The conductivities of gel electrolytes containing binary iodide systems with Pr₄NI and KI/RbI/CsI are higher and have shown values of 3.28, 3.43, and 3.23 mS cm⁻¹, respectively at room temperature. The influence of the nature of counterions on the performance of quasi-solid state dye-sensitized solar cells is investigated by assembling two series of cells. All the binary cationic solar cells have shown more or less enhancements of open circuit voltage, short circuit current density, fill factor, and efficiency compared to their single cation counterparts. This work highlights the importance of employing binary cations (a large and a small) in electrolytes intended for quasi-solid state solar cells. The percentage of energy conversion efficiency enhancement shown for the PECSCs made with electrolytes containing Pr₄NI along with Li⁺, Na⁺, K⁺, Rb⁺, and Cs⁺ iodides is 260.27, 133.65, 65.27, 25.32, and 8.36%, respectively. The highest efficiency of 4.93% is shown by the solar cell containing KI and Pr₄NI. However, the highest enhancements of ionic conductivity as well as the energy conversion efficiency were exhibited by the PECSC made with Li⁺-containing binary cationic electrolyte.

     

Functionalized styryl bipyridine as a superior chelate for a ruthenium sensitizer in dye sensitized solar cells

The new sensitizer MC119 has been synthesized and the solar cell constructed with 0.25 cm(2) active area photoelectrode in combination with an electrolyte composed of 0.6 M dimethylpropyl-imidazolium iodide (DMPII), 0.05 M I(2), 0.5 M TBP and 0.1 M LiI in acetonitrile achieved a solar to electric energy conversion efficiency (η) of 8.36% under Air Mass (AM) 1.5 sunlight, while the reference N719 sensitized solar cell exhibited η-value of 7.2%.     

Electrochemical impedance characterization and photovoltaic performance of N719 dye‐sensitized solar cells using quaternized ammonium iodide containing polyfluorene electrolyte solutions

This study develops a series of titanium oxide electrode‐based N719 dye‐sensitized solar cells (DSSCs) using quaternized ammonium iodide containing main‐chain and star‐shaped polyfluorene (MPF‐E and SPF‐E) electrolyte solutions. The electrochemical impedance and photovoltaic properties of the polyfluorene electrolyte‐based DSSCs were studied and compared to those of the poly(ethylene oxide) (PEO) electrolyte‐based DSSCs. As with the PEO electrolyte‐based DSSCs, the recombination impedance increased with increase in the polymer content for the MPF‐E electrolyte‐based DSSCs, whereas the photovoltaic performance did otherwise. Nevertheless, the reduction in the photovoltaic properties was not significant for the SPF‐E electrolyte‐based DSSCs. The electrochemical impedance and photovoltaic properties of the different polymer‐based DSSCs are also discussed as a function of the polymer concentration. Copyright © 2010 John Wiley & Sons, Ltd.     

A new class of cyclometalated ruthenium sensitizers of the type ĈNN for efficient dye-sensitized solar cells

A new class of cyclometalated ruthenium sensitizers incorporating a ?NN ligand and conjugated 2,2'-bipyridine in the ancillary ligand have been designed and synthesized. The photovoltaic performance of JK-206 using an electrolyte containing 0.6 M 1,2-dimethyl-3-propylimidazolium iodide, 0.05 M I(2), 0.1 M LiI, and 0.5 M tert-butylpyridine in CH(3)CN gave a short-circuit photocurrent density of 19.63 mA cm(-2), an open-circuit voltage of 0.74 V, and a fill factor of 0.72, affording an overall conversion efficiency of 10.39%. The efficiency is the highest one reported for dye-sensitized solar cells based on the cyclometalated ruthenium sensitizer of the type ?NN. Moreover, the same device using a polymer gel electrolyte exhibited a remarkable stability under 1000 h of light soaking at 60 °C, retaining 91% of the initial efficiency of 7.14%.     

一种新型聚合物固体电解质的导电性的研究

自从１９７５年Ｗｒｉｇｈｔ等［１］首次发现了ＰＥＯ 碱金属盐络合物的离子导电性后，人们对不同类型的聚合物固体电解质进行了深入的研究，其中最成功的是玻璃化温度Ｔｇ较低、盐浓度适中的“ｓａｌｔ ｉｎ ｐｏｌｙｍｅｒ”固体电解质［２，３］，但在没有其它小分...     

Asymmetric double-layer composite electrolyte with enhanced ionic conductivity and interface stability for all-solid-state lithium metal batteries

All-solid-state Li metal battery has been regarded as a promising battery technology due to its high energy density based on the high capacity of lithium metal anode and high safety based on the all solid state electrolyte without inflammable solvent.However,challenges still exist mainly in the poor contact and unstable interface between electrolyte and electrodes.Herein,we demonstrate an asymmetric design of the composite polymer electrolyte with two different layers to overcome the interface issues at both the cathode and the anode side simultaneously.At the cathode side,the polypropylene carbonate layer has enough viscosity and flexibility to reduce the inter-facial resistance,while at the Li anode side,the polyethylene oxide layer modified with hexagonal boron nitride has high mechanical strength to suppress the Li dendrite growth.Owing to the synergetic effect between different components,the asprepared double layer composite polymer electrolyte demonstrates a large electrochemical window of5.17 V,a high ionic conductivity of 6.1×10~(-4) S/cm,and a transfe rence number of 0.56,featuring excellent ion transport kinetics and good chemical stability.All-solid-state Li metal battery assembled with LiFePO_4 cathode and Li anode delivers a high capacity of 150.9 mAh/g at 25℃ and 0.1 C-rate,showing great potential for practical applications.     

基于偏氟乙烯-六氟丙烯共聚物凝胶电解质的染料敏化太阳电池光电性能研究

采用偏氟乙烯-六氟丙烯共聚物[P(VDF-HFP)]胶凝3-甲氧基丙腈基液体电解质, 成功制备了凝胶电解质并组装成准固态染料敏化太阳电池. 差示扫描量热测试结果表明凝胶电解质的溶液-凝胶转变温度(TSG)为71 ℃. 利用电化学方法分析了凝胶电解质中 电对的表观扩散系数及电导率低于液体电解质的原因, 同时结合暗态伏安法考察了电池内部TiO2多孔薄膜电极/电解质界面处的暗反应, 分析了凝胶化对电池光伏性能的影响. 进一步老化实验结果表明凝胶电池的稳定性明显优于液体电池.     

聚合物电解质在染料敏化太阳能电池中的应用进展

染料敏化太阳能电池(DSSC)由于成本低、污染小、制备工艺简单而受到广泛关注。电解质在其中起到桥梁的作用,能促使染料再生、输运空穴,从而完成整个光电循环过程,是DSSC重要的组成部分。本文简要介绍了DSSC的基本结构和工作原理,指出了传统液态电解质存在的问题,综述了近年来以聚合物为基体制备的新型固态聚合物电解质、凝胶聚合物电解质以及多孔聚合物电解质在DSSC中的应用,最后对聚合物电解质在染料敏化太阳能电池中的发展做出了展望。