전기삼투펌프를 포함한 직접메탄올연료전지의 개발
Development of Direct Methanol Fuel Cells Integrated with an Electroosmotic Pump
- 주제(키워드) Direct methanol fuel cell , Electroosmotic pump
- 발행기관 서강대학교 일반대학원
- 지도교수 김대중
- 발행년도 2011
- 학위수여년월 2011. 2
- 학위명 석사
- 학과 및 전공 일반대학원 기계공학과
- 실제URI http://www.dcollection.net/handler/sogang/000000046489
- 저작권 서강대학교의 논문은 저작권 보호를 받습니다.
초록/요약
Direct methanol fuel cells (DMFCs) are attractive energy conversion devices due to high volumetric energy density of methanol and simple structure with no moving part. DMFCs are being developed for portable electronic devices such as cellular phone, laptop and PDA. But commercialization of them has some challenges. As development of appropriate fuel supply module is one of challenges, a variety of methods were implemented. This thesis presents application of electroosmotic (EO) pumps for fuel supply of DMFCs. Accordingly, characterization of EO pumps using methanol/water mixtures with various compositions were first performed and then performance of DMFCs integrated with EO pumps were measured. The last thing shows the performance of EO pumps fabricated by porous polymer membranes. Characterization of EO pump using methanol/water mixtures is expressed in terms of maximum flow rate, maximum current, and maximum pressure. All these performance parameters increase linearly with the applied voltage. These parameters were normalized by the applied voltage and then normalized parameters were presented along methanol concentration. The maximum current per voltage and maximum pressure per voltage change monotonically with the methanol concentrations. The maximum flow rate per voltage however shows a nonlinear dependency against the methanol concentration. This dependency is mainly affected by viscosity, which also changes non-monotonically with the methanol concentration. Air breathing DMFC integrated the EO pump were characterized with 2, 4, and 6 mol/L methanol/water mixtures. Maximum gross power density of our free convection DMFC (operated 60ºC) is about 50 mW/cm2 using 2 mol/L concentration supplied by the EO pump. The DMFC stably operated during 100 minutes in the maximum power. Porous polymer membranes are successfully applied as porous materials for EO pumps and compared with porous glass frits. Normalized flow rate and flow rate per current of porous polymer membranes are better than porous glass frits. Porous polymer membranes can be implemented for miniaturization of EO pumps because of high flexibility.
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