{"title":"Unveiling frequency-dependent dielectric behavior of cellulose-based polymer electrolyte at various temperature and salt concentration","authors":"C. Ratri, Q. Sabrina, T. Lestariningsih, A. Nugraha, S. Astutiningsih, M. Chalid","doi":"10.14710/ijred.2023.53103","DOIUrl":null,"url":null,"abstract":"Dielectric behavior of cellulose-based polymer electrolyte was studied at various temperature and salt concentration. A polymer electrolyte membrane based on cellulose acetate (CA) as the polymer host and LiClO4 as the dopant salt was fabricated using the solution casting technique. The dopant salt concentration was varied as 0.3, 0.5, 0.67, and 1M. Dielectric relaxation spectroscopy characterization were performed using potentiostat at frequency ranging from 0.1 Hz to 1 MHz. Measurements were performed by sandwiching the membrane between stainless steel plates. The ionic conductivity was then calculated based on the Cole–Cole plot obtained from the impedance measurement. It was found that sample 1 M had the highest ionic conductivity at high frequencies. However, the frequency-dependent conductance plot showed that the ionic conductivity of the 1 M sample significantly decreased at low frequencies, i.e. from 3.41×10-5 S/cm at 1 MHz to 1.9×10-8 S/cm at 0.1 Hz. Other samples did not experience this phenomenon, including those with a Celgard© commercial membrane to represent commercial Li-ion batteries. This is caused by excess charge accumulation, leading to a high concentration of immobile charge carriers, which reduces the available free volume surrounding the polymer chain. This resulted in a significant decrease in ionic conductivity at low frequencies. Temperature variation was also performed on the conductivity measurement at 30-70 °C. Temperature variation showed more predictable behavior, where increasing the temperature activated charge carriers and enhanced ionic conductivity, from 1.81×10-5 S/cm at room temperature to 9.04×10-5 at 70°C. Sweeping across the frequency range results in a consistent sequence of ionic conductivities among the samples at various temperatures. This work is beneficial for evaluating a biomass-based polymer electrolyte complex in a Li-ion battery environment. Feasibility studies can be performed at various concentrations and temperatures to determine the optimal level of dopant salt input across a broad frequency range.","PeriodicalId":44938,"journal":{"name":"International Journal of Renewable Energy Development-IJRED","volume":" ","pages":""},"PeriodicalIF":2.4000,"publicationDate":"2023-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal of Renewable Energy Development-IJRED","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.14710/ijred.2023.53103","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ENERGY & FUELS","Score":null,"Total":0}
引用次数: 0
揭示纤维素基聚合物电解质在不同温度和盐浓度下的频率相关介电行为
研究了纤维素基聚合物电解质在不同温度和盐浓度下的介电行为。采用溶液浇铸法制备了以醋酸纤维素(CA)为高分子主体,氯化锂(LiClO4)为掺杂盐的聚合物电解质膜。掺杂盐浓度分别为0.3、0.5、0.67、1M。使用恒电位器在0.1 Hz至1 MHz的频率范围内进行介电弛豫光谱表征。测量是通过将膜夹在不锈钢板之间进行的。然后根据阻抗测量得到的Cole-Cole图计算离子电导率。发现样品1m在高频处离子电导率最高。然而,频率相关电导图显示,1 M样品的离子电导率在低频显著下降,即从1 MHz时的3.41×10-5 S/cm降至0.1 Hz时的1.9×10-8 S/cm。其他样品没有出现这种现象,包括那些使用Celgard©商业膜来代表商业锂离子电池的样品。这是由过量的电荷积累引起的,导致高浓度的不可移动的电荷载流子,这减少了聚合物链周围的可用自由体积。这导致在低频率离子电导率显著下降。在30-70°C的温度变化下也进行了电导率测量。温度变化表现出更可预测的行为,其中增加温度激活电荷载流子和增强离子电导率,从室温下的1.81×10-5 S/cm到70℃时的9.04×10-5。扫过频率范围的结果是在不同温度下样品之间离子电导率的一致序列。这项工作有助于在锂离子电池环境下评价生物质基聚合物电解质复合物。可行性研究可以在不同的浓度和温度下进行,以确定在宽频率范围内的最佳掺杂盐输入水平。
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