Compact power from breathe air
Invention field
The invention belongs to the fuel cell technology field, be mainly concerned with a kind of compact power from breathe air from the polymer electrolyte fuel cells of breathe air based on integrated fuel-device.
Background technology
The present invention relates to a kind of compact power of breathe air formula, it has light-duty, noiselessness and zero characteristic of polluting.This compact power can be used for multiple use, the peace and quiet energy that for example can be used as outdoor activities, automobile-used and home electronics, personal electronic equipments etc., this compact power mainly is made of the energy unit of hydrogen fuel device and power cell two parts of fuel cell pack, this hydrogen fuel device can be hydrogen storage device or apparatus for forming hydrogen, and this fuel cell pack is the self adaptation solid polymer cell heap of air self-suction formula.With common pressurization, heat and the fuel cell pack that is equipped with management systems such as hydro-thermal is compared, breathing fuel cell pack certainly is the operation (passive operation) of an entirely passive type, is very suitable for portable electrical power applications.In the process of breathing the fuel cell pile power generating certainly, fuel flow in the battery pile from fuel-device, the surrounding air generation electrochemical reaction of on membrane electrode, coming with breathing, discharge electric energy and water generation reaction, need not pump power from the fuel cell pack of breathe air and circulate or drain reactant or generate water.The optimal fuel of fuel cell pack is hydrogen.Polymer fuel cell has the advantages that operating temperature is low, power output is big, is a type in all types of fuel cells.
In U.S. Patent No. 5,595,834 and No.5,514, a kind of example of portable fuel battery heap has been described in 486, in the both sides that the anode (fuel electrode) and the negative electrode (oxygen electrode) of an element cell is arranged on the solid polymer electrolyte membrane sheet, fuel flow field plate and oxygen flow field plate are separately positioned on the side of anode (fuel electrode) and negative electrode (oxygen electrode); Separate by demarcation strip between two element cells.Thereby element cell is mutually integrated to be formed a plurality of element cells and piles up the integrally-built battery pile of formation, because these fuel cell stacking materials are applicable to lower powered fuel cell, so they can be designed to the fuel tank pile of the little and light weight of size.Chinese patent No.02106940.9 has done the improvement of several respects on this basis: (1) has removed fuel flow field plate, and the anode sides of each battery unit is provided with flow-field plate in fuel cell pack owing to not having, and has reduced the quantity of two surface contacts to a certain extent; (2) mode that fuel is supplied with from side opening, the end plate perforate of promptly having abandoned the fuel supply flow-field plate and being used for fuel supply have been changed.But on hold-down nut, open a fuel supply pore, pore and fuel distribution header connect, to be used for the center fueling from end plate.Fuel is not flowed through fuel flow field and is directly supplied to fuel distribution header place like this, and flow resistance can reduce, and can realize fuel supply stably; In traditional discharge process of breathing battery pile certainly, after hydrogen fuel is assigned to battery pile from hydrogen device fuel flow field plate carries out electrochemical reaction, if do not discharge the outlet of tail gas, generation water so probably can accumulate gradually in fuel flow channel, make battery pile ponding and make voltage and electric current descend, influence the battery pile output performance.Traditional method is at hydrogen fuel house steward's end vent valve to be installed, and its structure is at patent No.5,595,834 with patent No.02106940.9 in have a detailed description.
Yet in the stack design of above traditional breathe air formula, also there is very big problem: at first, in above-mentioned patent, all adopted the metal demarcation strip more or less, battery pile weight and volume have been increased like this, the more important thing is has increased the contact interface in the battery pile, caused the internal resistance increase, and the metal surface is easy to be corroded, the internal resistance meeting is increasing along with the carrying out of discharge, thereby reduces the power output of entire cell heap.In patent No.02106940.9, though removed fuel flow field plate, can reduce the battery pile internal resistance outwardly, but because the metal surface directly contacts with fuel cell membrane electrode, membrane electrode is a weakly acidic environment, and metal demarcation strip surface corrosion effect meeting is strengthened like this, not only may increase internal resistance, but also may discharge the metal impurities ion, the membrane electrode core component of battery pile was lost efficacy.On the other hand,, can cause negative effect,, form ' dead band ' that hydrogen can't arrive, cause performance degradation because the electrochemical reaction product water will be resident in electrode easily to the even distribution of fuel owing to lack fuel flow field plate.Secondly fuel cell pack is mutually not integrated with the hydrogen fuel device, and just the power cell of power conversion can not become compact power.Once more, at hydrogen fuel distribution house steward's end vent valve being installed there are many unfavorable factors, because under the pressure differential effect of and ambient pressure inner in battery pile, discharges accumulated water and waste gas by vent valve, this just requires vent valve periodically to be opened, and makes it be in emissions status.The operate as normal of self-respiration type fuel battery heap just needs manual intervention like this.The deficiency of time of event exhaust valve discharging will cause electrical property to descend; But the event exhaust valve discharging is frequent, will waste a large amount of fuel hydrogen.Though vent valve also can be operated by automation equipment on the other hand, the hydrogen fuel of discharging also can reclaim by hydrogen pump, and the passive type operation of battery pile is had a greatly reduced quality.Remove this part, because hydrogen belongs to inflammable explosive article, vent valve batch (-type) directly discharging has brought harmful effect for the fail safe of using.Certainly also there are problems such as heavy, the complex-shaped and size of maintenance work is bigger than normal.
Summary of the invention
The purpose of this invention is to provide a kind of compact power from breathe air, the energy unit fuel-device 9 of described compact power from breathe air is connected in series with fastening bolt 5 and fastening bolt 6 with the power cell that is made of fuel cell pack bipolar plates 1, membrane electrode 2, fuel flow field plate 3, air flow field plate 4, collector plate 10, end plate 7 and packing ring 8; It is characterized in that: adopt two sides all to have the circular integration graphite bi-polar plate of gas distribution groove to replace fuel flow field plate, air flow field plate and metal demarcation strip, the periphery of this bipolar plates and interior week are provided with seal groove 17, connect at the mode and the outside air of bipolar plates neighboring part by hole 14 or bridge formation, and partly entering fuel central dispense pipe 13 by fuel connecting hole 12 by the mode and the fuel hydrogen in the fuel-device of hole 14 or bridge formation in inner periphery, hydrogen fuel and air are isolated in both sides respectively by bipolar plates 1.
The air flow field distribution side of described bipolar plates is formed the water conservancy diversion network by the guiding gutter 16 that interpenetrates, and provides the hole 14 of matrix 15 peripheries directly to communicate with outside air; Air flow inlet and outlet hole 14 is square, circular or trapezoidal.
The groove width of described guiding gutter 16 can be continuously or is changed discontinuously, guiding gutter 16 be shaped as straight line, curve, broken line or network shape.The degree of depth of guiding gutter can change continuously or discontinuously, and bottom land is plane, step, wave or curve form.
The hydrogen distribution side of described bipolar plates is formed the hydrogen flow guide network by the guiding gutter that interpenetrates 16 similar to air flow field distribution side.
Described membrane electrode 2 is made of hydrophobic carbon paper 19, anode hydrophobic carbon bisque 20, anode catalyst layer 21, cathode catalysis layer 22, solid polymer electrolyte membrane sheet 18; Used carbon paper is composited by carbon fiber, and adopts polytetrafluoroethylplastic plastic to carry out hydrophobic treatment.
The invention has the beneficial effects as follows: 1. the bipolar plates of Cai Yonging is except playing the effect of automatic distribution reacting gas, also has good thermolysis, because the air-distribution flow field communicates with outside air fully, along with the free convection of air, diffusion or along with the discharging of electrochemical reaction product evaporation of water, play good thermolysis naturally.2. removed the metal demarcation strip, helped the Self-breathing of air, helped the even distribution of fuel hydrogen, can not produce fuel and can not arrive ' dead band '; Reduce component count and mounting hardness widely, reduce the quantity of two surface contacts and the resistance of contact portion, also prevented the corrosion phenomenon that uses metal to cause, thereby reduced the internal resistance of pile effectively, improve the service life of battery, can realize high efficiency portable power generation.
3. by the special distribution of through air conducting groove, realize the good heat radiating method of natural air air cooling, simplified fuel cell system, its component count is reduced, reduced cost.4. fuel-device is heaped with the polymer fuel cell of breathe air, and the metal demarcation strip that removes fuel cell pack by integrated special bipolar plates to reduce the interface contact portion, the internal resistance of battery pile is reduced, improve electrical property thus.
5. remove baroque vent valve, discharge accumulated water in the anode, realize manually intervening, strengthened the adaptivity of its generating from the nothing of breathing the battery pile operation by the synergy of membrane electrode and air flow field plate.Thereby the complexity that reduces to operate, insecurity and further reduce size, weight.This invention has vast market prospect.
Description of drawings
Fig. 1 is the compact power structural representation from breathe air.
Fig. 2 A is the hydrogen fuel flow field schematic diagram of bipolar plates.
Fig. 2 B is the air flow field schematic diagram of bipolar plates.
Fig. 2 C is the front schematic view of two plate plates.
Fig. 3 is the membrane electrode assembly schematic diagram.
Fig. 4 is the compact power stereo appearance figure from breathe air.
Embodiment
The present invention is a kind of compact power from breathe air.In the structure of the compact power from breathe air shown in Figure 1, energy unit hydrogen fuel device 9 is connected in series with fastening bolt 5 and fastening bolt 6 with the power cell that is made of fuel cell pack bipolar plates 1, membrane electrode 2, fuel flow field plate 3, air flow field plate 4, collector plate 10, end plate 7 and packing ring 8.The present invention adopts two sides all to have the circular integration graphite bi-polar plate of gas distribution groove to replace fuel flow field plate, air flow field plate and metal demarcation strip.The periphery of this bipolar plates and interior week are provided with seal groove 17, connect at the mode and the outside air of bipolar plates neighboring part by hole 14 or bridge formation, and partly entering fuel central dispense pipe 13 by fuel connecting hole 12 by the mode and the fuel hydrogen in the fuel-device of hole 14 or bridge formation in inner periphery, hydrogen fuel and air are isolated in both sides respectively by bipolar plates.In the air flow field distribution side of bipolar plates, form the water conservancy diversion network by the guiding gutter 16 that interpenetrates, provide the hole 14 of matrix 15 peripheries directly to communicate with outside air; Air flow inlet and outlet hole 14 is square, circular or trapezoidal; The groove width of guiding gutter 16 can be continuously or is changed discontinuously, guiding gutter 16 be shaped as straight line, curve, broken line or network shape.The degree of depth of guiding gutter can change continuously or discontinuously, and bottom land is plane, step, wave or curve form.In the hydrogen distribution side of bipolar plates, form the hydrogen flow guide network (shown in Fig. 2 A~2C) by the guiding gutter that interpenetrates 16 similar to air flow field distribution side.
Above-mentioned membrane electrode 2 (as shown in Figure 3) uses the porous carbon paper 19 of high hydrophobicity to make anode substrate, and distributing on the one side surface has the hydrophobicity carbon dust layer 20 in micropore (the equivalent aperture is less than the equivalent aperture of carbon paper), prepares anode catalyst layer 21 substrates like this; Use the porous carbon paper 19 of high hydrophobicity to make cathode substrate, but top no hydrophobic carbon dust layer 20 directly is used as the substrate of cathode catalysis layer 22.Then they are prepared into membrane electrode 2 assemblies with solid polymer dielectric film sheet 18.The air flow field groove of bipolar plates in pile (or air flow field plate) helps the negative electrode draining through hydrophobic functionalization, prevents that electrochemical reaction from generating the accumulation of water, reduces the water activity of cathode side.
In the present invention, remove complicated vent valve and the securing member of having simplified battery pile.In order to keep good hydrogen sealing, reduced the use of movable part nut, and only adopted two bolts to carry out scheme fastening and formation hydrogen fuel distribution duct.Wherein a bolt axially with radially all have fuel connecting hole 12, and on its fixing head, form hole 11 with internal thread, be connected with fuel-device, realize the hydrogen perforation of fuel-device and battery pile.Battery pile fastening is that the screw front end by a bolt is connected under the interlock of screw thread with the screw front end of another root bolt, transmission by pad pressure makes the battery pile end plate compress, realized that connector is positioned over the new design of pile inside, help reducing volume, weight and cost, this compact power promptly can horizontal positioned with respect to axis direction like this, also can vertically place.Simplify secure component, air-tightness is good, and because of not having connector to make battery pile attractive in appearance in the battery pile outside, need not manual intervention in the power generation process, has strengthened its practicality, can strengthen the public's acceptance, helps promoting the use of
In addition, the present invention organically combines on-the-spot hydrogen source device and self-respiration type fuel battery heap, has realized promptly having the compact power that energy unit has power cell again veritably.Can generate electricity as compact power in remote place away from the High Pressure Hydrogen gas cylinder, need not use the AC network charging, just can carry out undisturbedly electrochemical reaction by respiratory oxygen from air as long as add fuel, constantly export electric energy, be a kind of very convenient compact power.
The solid polymer electrolyte membrane sheet comprises use proton exchange membrane that fluoridize or that have aromatic ring structure or their organic and inorganic compound proton exchange membrane.Adopt the perfluorinated sulfonic acid proton exchange membrane in this enforcement, its thickness is between 25 μ m~μ 180m, and its EW value is between 600~1300.Solid polymer electrolyte membrane generally need be passed through H
2O
2, H
2SO
4Weak solution handle, to remove organic impurities and protonated, also it has been carried out the surface roughening processing in the present embodiment.At last electrode is cut into annular electrode by bipolar plates 1 shape, and is combined with each other, be prepared into membrane electrode assembly 2 with solid polymer electrolyte membrane.
Figure 4 shows that the compact power stereo appearance figure from breathe air of said structure.Its operation principle is as follows.
Fuel-device be this compact power in energy unit, the storage of its fuel or generation have determined the energy density of power supply; From the fuel cell pack of breathing is the power cell of power supply, and the electrochemical reaction of Fa Shenging has determined the size of power output therebetween.After starting power supply, fuel hydrogen in the fuel-device enters fuel central dispense pipe 13 by fuel connecting hole 12, by the duct, inside on bipolar plates 1, the fuel distribution plate 3 hydrogen fuel is transported to the fuel flow field face of each battery unit by this fuel central dispense pipe 13 again, and equably hydrogen is distributed in the anode-side of membrane electrode 2 by the guiding gutter in the fuel flow field 16.The surrounding air periphery duct 14 of passing bipolar plates 1, air distribution pole plate 4 from the external world by modes such as convection current, diffusions enters the air flow field face of each battery unit on the other hand, and equably airborne oxygen is distributed in the cathode side of membrane electrode 2 by the guiding gutter in the air flow field.Be distributed with hydrogen fuel gas and oxygen respectively in the both sides of the core component membrane electrode 2 of battery pile like this, electrochemical reaction just here takes place.Hydrogen is dissociated into proton and electronegative electronics under the effect of anode catalyst, proton is with hydration form H
+. (nH
2O) in solid electrolyte film from a sulfonic group (SO
3H) transfer to another sulfonic group, arrive negative electrode at last, realize proton conductive.This migration of proton causes anode electronegative electron accumulation to occur, thereby has become an electronegative terminal (negative pole).Meanwhile, the electronics that the oxygen molecule of negative electrode and catalyst action produce down reacts, become oxonium ion, make negative electrode become the terminal of positively charged (positive pole), its result causes having produced a voltage between the positively charged terminal of the electronegative terminal of anode and negative electrode.Battery back of the body units in series just can obtain the stack of voltage.If link to each other the two poles of the earth by external circuit this moment, electronics will flow to negative electrode from anode by the loop, thereby produces electric energy.