【正文】 characteristics have improved water drainage rate significantly. The paper investigates origins and movement directions of water in fuel cells systematically, bining with properties of CNT paper and analyzes influences it causes to .The result shows that this novel with CNT paper as gas diffusion layer(GDL) presents obvious advantages over traditional fuel cells with carbon paper as GDL. Under the operation condition of 60 degrees centigrade and provided by the methanol concentration of 8mol/L, this novel fuel cell is able to reach the highest power density of , which exceeds the traditional one by %. What is more, the CNT GDL also improves the stabilities of fuel cells when they are applied to longtime discharge process. At the methanol concentration of 6mol/L and operational current density is 100mA/cm2, this novel fuel cell is able to work 494min continuously, which exceeds the traditional one by %. After longtime discharge process, this paper calculates water transmission coefficient quantitatively. The result also certifies that this novel CNT cathode GDL reduce water permeation from anode to cathode apparently, thus it is capable of avoiding water flooding in the cathode. Keywords: carbon nanotubes paper, cathode water flooding, capillary condensation, Micro direct methanol fuel cell 哈爾濱工業(yè)大學(xué) 本科畢業(yè) 設(shè)計(jì)（ 論文 ） III 目錄 摘 要 ................................................................................................................................. I Abstract............................................................................................................................. II 目錄 ................................................................................................................................. III 第 1 章 緒論 ..................................................................................................................1 研究目的和意義 ..............................................................................................1 DMFC 陰極水管理研究現(xiàn)狀 .........................................................................2 優(yōu)化陰極結(jié)構(gòu)材料 ...............................................................................2 引入新型陰極微結(jié)構(gòu) ...........................................................................3 主要研究內(nèi)容 ..................................................................................................7 第 2 章 陰極水管理機(jī)理 ..............................................................................................8 DMFC 工作原理 .............................................................................................8 水的傳輸機(jī)理 ..................................................................................................9 擴(kuò)散 .......................................................................................................9 液壓滲透 .............................................................................................10 電拖拽 .................................................................................................10 CNT 基新型陰極擴(kuò)散電極結(jié)構(gòu) ...................................................................10 CNT 紙的特點(diǎn) ....................................................................................10 CNT 紙內(nèi)水的傳 輸特點(diǎn) ....................................................................13 本章小結(jié) ........................................................................................................15 第 3 章 新結(jié)構(gòu) MEA 的制備 .....................................................................................16 MEA 的設(shè)計(jì)和制備 ......................................................................................16 組裝和活化 ....................................................................................................20 本章小結(jié) ........................................................................................................22 第 4 章 結(jié)果分析與討論 ............................................................................................24 甲醇濃度的影響 ............................................................................................24 溫度的影響 ....................................................................................................30 長時(shí)間放電測試 ............................................................................................32 水傳輸系數(shù)、能量轉(zhuǎn)換率、燃料利用率 ....................................................35 水傳輸系數(shù)的測試原理和方法 .........................................................35 哈爾濱工業(yè)大學(xué) 本科畢業(yè) 設(shè)計(jì)（ 論文 ） IV 能量轉(zhuǎn)換率的測試原理和方法 .........................................................38 燃料利用率的測試原理和方法 .........................................................38 結(jié)果和討論 .........................................................................................39 交流阻抗測試 ................................................................................................40 本章小結(jié) ........................................................................................................41 第 5 章 結(jié)論 ................................................................................................................43 參考文獻(xiàn) .........................................................................................................................44 攻讀學(xué)士學(xué)位期間發(fā)表的論文 .....................................................................................48 致 謝 ...............................................................................................................................49 附錄 1 外文譯文 ...........................................................................................................50 對于空氣自呼吸式微型直接甲醇燃料電池中基于毛細(xì)管的陰極除水結(jié)構(gòu)的研究 .............................................................................................................................50 摘要： .....................................................................................................................50 1. 介紹 .................................