A new method of manufacturing micro-flow channels on graphite composite bipolar plate(GCBPP) microplaning using specially designed multi-tooth tool is proposed. In this method, several or even dozens of parallel micro...A new method of manufacturing micro-flow channels on graphite composite bipolar plate(GCBPP) microplaning using specially designed multi-tooth tool is proposed. In this method, several or even dozens of parallel micro-flow channels ranging from 100 μm to 500 μm in width can be produced simultaneously. But, edge chippings easily occur on the rib surface of GCBPP during microplaning due to brittleness of graphite composites. Experimental results show that edge chippings result in the increase of contact resistance between bipolar plate and carbon paper at low compaction force. While the edge chippings scarcely exert influence on the contact resistance at high compaction force. Contrary to conventional view, the edge chippings can significantly improve performance of microfuel cell and big edge chippings outperform small edge chippings. In addition, the influence of technical parameters on edge chippings was investigated in order to obtain big, but not oversized edge chippings.展开更多
Bipolar plates for proton exchange membrane fuel cell (PEMFC) where polymer is used as binder and graphite is used as electric filler were prepared by means of compression molding technology. Study on the effects of g...Bipolar plates for proton exchange membrane fuel cell (PEMFC) where polymer is used as binder and graphite is used as electric filler were prepared by means of compression molding technology. Study on the effects of graphite particle size and shape on the bipolar plate performance, such as electrical conductivity, strength, etc. showed that with decrease of graphite particle size, bulk electrical conductivity and thermometric conductivity decreased, but that flexural strength was enhanced. After spherical graphite occurrence in flake-like form, the flexural strength of the bipolar plate was enhanced, electrical conductivity increased but thermal conductivity decreased in direction paralleling pressure direction, and both electrical conductivity and thermometric conductivity reduced in direction perpendicular to pressure direction.展开更多
In order to balance the conductivity and flexural strength of graphite composite bipolar plates,the influence of conductive filler on the properties of graphite composite bipolar plate was comprehensively studied by u...In order to balance the conductivity and flexural strength of graphite composite bipolar plates,the influence of conductive filler on the properties of graphite composite bipolar plate was comprehensively studied by using phenolic resin as binder,natural flake graphite as conductive substrate and functional carbon materials with different structures as auxiliary filler.The results show that the particle size of conductive substrate has an important influence on the conductivity enhancement of auxiliary filler.The influence of conductive particle size on auxiliary filler electrical conductivity improvement was first investigated in this research.The effects of various auxiliary filler concentrations on improving electrical conductivity and flexural strength were then examined.This research has substantial implications for the balance of electrical conductivity and flexural strength of graphite composite bipolar plates.展开更多
Epoxy resin-reinforced graphite composites have found extensive application as bipolar plates in fuel cells for stationary power supplies,valued for their lightweight nature and exceptional durability.To enhance the i...Epoxy resin-reinforced graphite composites have found extensive application as bipolar plates in fuel cells for stationary power supplies,valued for their lightweight nature and exceptional durability.To enhance the interfacial properties between graphite and epoxy resin(EP),surface oxidation of graphite was carried out using diverse functional groups.Experimental assessments illustrated that the composites with graphite oxide resulted in heightened mechanical strength and toughness compared to pristine graphite,which could be attributed to the excellent interface connection.Moreover,these composites displayed remarkable conductivity while simultaneously retaining their mechanical attributes.Furthermore,molecular dynamics simulations outcomes unveiled that the inclusion of oxygen-containing functional groups on the graphite surface augmented the interfacial energy with EP,and the interface morphology between graphite and resin exhibited heightened stability throughout the stretching process.This simple and effective technique presents opportunities for improving composites interfaces,enabling high load transfer efficiency,and opens up a potential path for developing strong and tough composite bipolar plates for fuel cells.展开更多
基金Project(51075155)supported by the National Natural Science Foundation of ChinaProject(2013ZZ017)supported by the Fundamental Research Funds for the Central Universities,China
文摘A new method of manufacturing micro-flow channels on graphite composite bipolar plate(GCBPP) microplaning using specially designed multi-tooth tool is proposed. In this method, several or even dozens of parallel micro-flow channels ranging from 100 μm to 500 μm in width can be produced simultaneously. But, edge chippings easily occur on the rib surface of GCBPP during microplaning due to brittleness of graphite composites. Experimental results show that edge chippings result in the increase of contact resistance between bipolar plate and carbon paper at low compaction force. While the edge chippings scarcely exert influence on the contact resistance at high compaction force. Contrary to conventional view, the edge chippings can significantly improve performance of microfuel cell and big edge chippings outperform small edge chippings. In addition, the influence of technical parameters on edge chippings was investigated in order to obtain big, but not oversized edge chippings.
文摘Bipolar plates for proton exchange membrane fuel cell (PEMFC) where polymer is used as binder and graphite is used as electric filler were prepared by means of compression molding technology. Study on the effects of graphite particle size and shape on the bipolar plate performance, such as electrical conductivity, strength, etc. showed that with decrease of graphite particle size, bulk electrical conductivity and thermometric conductivity decreased, but that flexural strength was enhanced. After spherical graphite occurrence in flake-like form, the flexural strength of the bipolar plate was enhanced, electrical conductivity increased but thermal conductivity decreased in direction paralleling pressure direction, and both electrical conductivity and thermometric conductivity reduced in direction perpendicular to pressure direction.
基金the financial supports from the National Key R&D Program of China(Nos.2020YFB1505904 and 2018YFB1502502-04)。
文摘In order to balance the conductivity and flexural strength of graphite composite bipolar plates,the influence of conductive filler on the properties of graphite composite bipolar plate was comprehensively studied by using phenolic resin as binder,natural flake graphite as conductive substrate and functional carbon materials with different structures as auxiliary filler.The results show that the particle size of conductive substrate has an important influence on the conductivity enhancement of auxiliary filler.The influence of conductive particle size on auxiliary filler electrical conductivity improvement was first investigated in this research.The effects of various auxiliary filler concentrations on improving electrical conductivity and flexural strength were then examined.This research has substantial implications for the balance of electrical conductivity and flexural strength of graphite composite bipolar plates.
基金the financial supports from the National Key R&D Program of China(No.2020YFB1505901)。
文摘Epoxy resin-reinforced graphite composites have found extensive application as bipolar plates in fuel cells for stationary power supplies,valued for their lightweight nature and exceptional durability.To enhance the interfacial properties between graphite and epoxy resin(EP),surface oxidation of graphite was carried out using diverse functional groups.Experimental assessments illustrated that the composites with graphite oxide resulted in heightened mechanical strength and toughness compared to pristine graphite,which could be attributed to the excellent interface connection.Moreover,these composites displayed remarkable conductivity while simultaneously retaining their mechanical attributes.Furthermore,molecular dynamics simulations outcomes unveiled that the inclusion of oxygen-containing functional groups on the graphite surface augmented the interfacial energy with EP,and the interface morphology between graphite and resin exhibited heightened stability throughout the stretching process.This simple and effective technique presents opportunities for improving composites interfaces,enabling high load transfer efficiency,and opens up a potential path for developing strong and tough composite bipolar plates for fuel cells.
