【正文】 __________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ 答辯委員會主任（簽字）： 職稱： 答辯委員會副主任（簽字）： 答辯委員會委員（簽字）： ___________ ___________ ___________ __________ __________ ___________ ___________ ___________ __________ __________ ___________ ___________ ___________ __________ __________ 年月日 哈爾濱工業(yè)大學(xué)畢業(yè)設(shè)計 （論文）任務(wù)書 姓名： 鄭雪 院（系）： 航天學(xué)院 專業(yè)： 電子信息科學(xué)與技術(shù) 班號： 1021202 任務(wù)起至日期： 2021 年 12 月 9 日至 2021 年 6 月 25 日 畢業(yè)設(shè)計（論文）題目： CNT 基陰極擴散電極的研究 立題的目的和意義： 微型直接甲醇燃料電池 （ DMFC? ）由于具有體積小巧、攜帶方便、能量轉(zhuǎn)換效率高和結(jié)構(gòu)簡單的優(yōu)點，成為未來便攜式西東能源的首選。本課題的研究目的就是設(shè)計新型的基于 CNT 的陰極擴散電極，以解決陰極水淹和 O2 傳質(zhì)。 （ 2） 進度安排： 2021 年 12 月 26 日～ 2021 年 1 月 14 日：畢業(yè)實習(xí)，閱讀國內(nèi)外文獻，了解 DMFC在國內(nèi)外的發(fā)展現(xiàn)狀，掌握 DMFC 的工作原理； 2021 年 1 月 14 日～ 2021 年 2 月 25 日：熟悉實驗室環(huán)境以及實驗儀器，了解實驗室所使用被動式 DMFC 的性能； 2021 年 2 月 26 日～ 2021 年 3 月 16 日：進一步了解研究背景、國內(nèi)外研究現(xiàn)狀，撰寫開題報告并進行開題答辯； 2021 年 3 月 17 日～ 2021 年 3 月 31 日：確定實驗基本步驟，解決實驗存在的困難。 2021 年 6 月 1 日～ 2021 年 6 月 25 日：撰寫畢業(yè)論文，準備畢業(yè)答辯。 隨著微電子機械系統(tǒng)（ MEMS）技術(shù)的快速發(fā)展， DMFC? 的尺寸越來越小，使得 DMFC? 中 的 水管理系統(tǒng)成為關(guān)鍵。結(jié)果表明 ，具有這種 CNT 基 新型陰極擴散電極 的 DMFC? 在 高溫高濃度下表現(xiàn)出 很強 的優(yōu)越性， 在 60176。 關(guān)鍵詞 ： CNT 紙； 陰極水淹 ；毛細凝聚； DMFC? 哈爾濱工業(yè)大學(xué) 本科畢業(yè) 設(shè)計（ 論文 ） II Abstract Micro direct methanol fuel cells ( DMFC? )have been considered as one of the leading candidates for the future portable power sources because of their many advantages including small size, easy operation, high energy density and so on. Water management is one of the most important factors which have impact on electrode potential and overall cell voltage. The amount of water in sDMFC? influences cell electrode activation energy, humidity of electrolyte membrane and efficiency of reactant transfer directly. As micro electromechanical technology develops, the size of bees smaller and smaller, which necessitates highefficiency water management of cells. In this paper, a novel gas diffusion electrode made of carbon nanotubes (CNT) paper is designed to avoid cathode water flooding. CNT paper has strong abilities of water absorption and dispersion, thus it can reduce difficulties of oxygen transfer. Moreover, capillarylike structures in CNT paper are able to induce capillary condensation of water vapor produced by cathode reduction reaction, then condensed water evaporates into air through CNT paper by capillary forces. This 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（ 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 陰極水管理機理 ..............................................................................................8 DMFC 工作原理 .............................................................................................8 水的傳輸機理 ..................................................................................................9 擴散 .......................................................................................................9 液壓滲透 .............................................................................................10 電拖拽 .................................................................................................10 CNT 基新型陰極擴散電極結(jié)構(gòu) ...................................................................10 CNT 紙的特點 ....................................................................................10 CNT 紙內(nèi)水的傳輸特點 ....................................................................13 本章小結(jié) ............................................................