Impact of Thickness of Polymer Electrolyte Membrane on Temperature Distributions in Single Cell of Polymer Electrolyte Fuel Cell Operated at High Temperature

Abstract

This study is to understand the impact of operating condition, especially initial operation temperature (T ini ) which is set in high temperature range, on the temperature profile of the interface between PEM (polymer electrolyte membrane) and catalyst layer at the cathode (i.e., the reaction surface) in a single PEFC (polymer electrolyte fuel cell). A 1D multi-plate heat transfer model based on the temperature data of separator measured using thermograph in a power generation experiment was developed to evaluate the reaction surface temperature (T react ). This study investigated the effects of T ini , flow rate and relative humidity of supply gas as well as thickness of PEM on the temperature distribution on reaction surface. As a result, the impact of flow rate of supply gas on the temperature distribution is not significant irrespective of relative humidity conditions as well as PEM type. When operated at high temperature, the temperature distribution is relatively flat in the case of thicker PEM (Nafion 115), while T react rises from the inlet to the outlet large and the temperature distribution is wide in the case of thin PEM (Nafion 211) irrespective of relative humidity condition. Since the water transfer through PEM in the case of Nafion 211 is better than Nafion 115 due to thin PEM, the power generation is promoted along the gas flow with the aid of humidification by water produced from electrochemical reaction.

Impact of Separator Thickness on Temperature Distribution in Single Polymer Electrolyte Fuel Cell Based on 1D Heat Transfer

“…A few researchers [4] [22] [23] have reported numerical simulation on temperature distribution in a single PEFC which is operated at a higher temperature than usual. However, only a few papers [4] [22] have investigated the tempera-ture distribution on the interface between PEM and electrode at the cathode, which is defined as the reaction surface in this study, excluding the research conducted by the authors [24] [25] [26] [27]. The previous studies [24] [25] [26] [27] have confirmed the thickness effect of not only PEM but also GDL on the distribution of temperature at reaction surface (T react ) in a single PEFC at a higher temperature, i.e.…”

“…However, only a few papers [4] [22] have investigated the tempera-ture distribution on the interface between PEM and electrode at the cathode, which is defined as the reaction surface in this study, excluding the research conducted by the authors [24] [25] [26] [27]. The previous studies [24] [25] [26] [27] have confirmed the thickness effect of not only PEM but also GDL on the distribution of temperature at reaction surface (T react ) in a single PEFC at a higher temperature, i.e. 90˚C or 100˚C by the heat transfer model using the experimental temperature distribution data gotten by means of thermograph.…”

“…Since this procedure can measure the temperature distribution with no disturbance of the heat and mass transfer phenomena and power generation characteristics because of sensor installation, it can be claimed that the temperature distribution during the power generation can be measured accurately. Using the measured data, the previous studies [27] [30] [31] have challenged to develop an empirical model in order to predict the distributions of T react . Though the authors have reviewed the literature, it is confirmed there is no previous study to estimate the distribution of T react using the temperature data at separator's back.…”

Analytical investigation on impact of presence of MPL on temperature distribution in single cell of PEFC under high temperature condition

“…トスポットが生成すると電解質膜(PEM)の熱分解や，熱応力起因の破損が生じる ことから， 高温で運転する際にはこれまで以上に温度制御に配慮が必要となる． 200℃程度までの高温運転に関する PEFC の各種特性について報告例 (Chen and Su, 2018;Devrim et al, 2018;Kannan et al, 2018;Nalbant et al, 2018; はいくつかあるが，それらの多くが新材料の開発 (Devrim et al, 2018;や 電流密度や電圧変化のような発電特性評価 (Chen and Su, 2018;Nalbant et al, 2018;もしくは 耐久性評価 (Kannan et al, 2018;に関する報告であり，PEFC 単セル内部の温度分布特性につ いて評価した研究は少ない Lee et al, 2017;) ．さらに，カソード還元 反応に重要な役割を担う PEM とカソード触媒層の界面(本論文では反応面と定義する)の温度分布について評 価した研究は，著者らの過去の取り組み Nishimura et al, 2018) Table 1 Specification of PEFC components referred from the manufacture catalog and previous studies (Nishimura et al, 2018;Cooper et al, 2017;Penga et al, 2016;Nishimura et al, 2012;Kang and Ju, 2009). conductivity is promoted by humidification of PEM and the thermal conductivity of GDL is promoted by penetration of MPL into GDL.…”

“…Operating conditions of power generation for temperature measurement by thermograph. Area display of in-plane temperature distribution measured by thermograph Nishimura et al, 2018). …”