CN101546833B - Deformation prevention method in direct alcohol fuel cell profiled porous cathode support body forming - Google Patents

Abstract

The invention discloses a deformation prevention method in direct alcohol fuel cell profiled porous cathode support body forming, which comprises the steps of biscuit producing, sintered body forming, and the like. The cathode support body biscuit and the sintered body of the invention do not deform.

Description

Direct alcohol fuel cell profiled porous cathode support body forming anti-deformation method

Technical field:

The present invention relates to a kind of direct alcohol fuel cell profiled porous cathode support body forming method.

Background technology:

Methyl alcohol, ethanol and propyl alcohol etc., all can be used as the fuel of direct alcohol fuel battery, wherein, direct methanol fuel cell (Direct methanol fuel cell, DMFC) and directly alcohol fuel cell (Direct ethanol fuel cell, DEFC) because of its used methyl alcohol or ethanol wide material sources, cheap, and its energy utilization efficiency height, eco-friendly operational mode, normal temperature operability and advantage such as be easy to carry, thus outstanding person in the new fuel cell become, in military affairs, communications and transportation, fields such as telecommunications have application prospects.

Traditional direct alcohol fuel battery mainly is made of bipolar plates (mainly adopting graphite or metal to prepare), catalysis-diffusion layer and polymer dielectric film, the shape of fuel cell mostly is flat, and the catalysis-diffusion layer of negative electrode and anode and polymer dielectric film adopt hot pressing mode to be shaped to " three-in-one " membrane electrode assembly.But there is following shortcoming in plate direct alcohol fuel battery: (1) adopts the bipolar plate structure with complex flowfield, manufacturing cost height; (2) prepared miniature and large-scale DMFC weight, volume are big; (3) structure of anode is unfavorable for the discharging of byproduct of reaction (as carbon dioxide), and the structure of negative electrode also is unfavorable for the discharge of byproduct of reaction (as water), influences the stability of battery under long-term work; (4) all adopt liquid methanol to act as a fuel in the DMFC research wherein, have the methanol crossover phenomenon, the DMFC power density reduces greatly; (5) direct fuel-in-storage needs complicated intake line; (6) be not suitable for the mobile phase (fuel) of canned non-liquid state.

The key of abnormally-structured direct alcohol fuel battery is the selection and the shaping of circular or square cathode support body material.After determining material prescription, most important is exactly to determine suitable forming and anti-deformation technology.If it is improper to select, not only produce the problem of manufacturing cost costliness, commercial application difficulty, and make cathode support body forming difficulty and performance low easily, as produce distortion, cracking, poorly conductive, poor mechanical property, thereby cause that diffusion layer and Catalytic Layer are difficult to apply, rete applies or wrap up problems such as bad, thereby reduced the performance of direct methanol fuel cell.

Find through literature search prior art, the preparation process of a kind of sleeve cathode and anode introduced in " A tubular direct methanolfuel cell with Ti mesh anode " literary composition that people such as Zhi-Gang Shao deliver on " Journal ofPower Sources " 160 (2006) 1003-1008.What wherein cathode support body material adopted is the titanium net of tubulose.Successively with the method for immersion coating, prepare diffusion layer and Catalytic Layer on titanium pipe network surface, and then be coated with Nafion solution surperficial the dripping of diffusion layer, this solution becomes polymer dielectric film after solidifying, thereby makes negative electrode.But the employed tubulose titanium net that is used to make cathode support body is provided by the Heggemann company of Germany in this paper, and because of its purity height (＞99.99%) and adopt laser welding technology to make, the cost costliness is so be difficult to popularize use.In addition, because the titanium net mechanical property that adopts is low, easy deformation has influenced the coating of diffusion layer and catalyst layer, has also influenced the coating or the parcel of rete, has reduced the performance of battery.

By literature search, " rheological characteristic of carbonaceous mesophase spherules suspended substance and the research of gel injection molding and forming technology " literary composition that people such as Li Fei deliver on " Journal of Inorganic Materials " 20 (2005) 299-304, introduce and adopt gel injection-moulding technological forming dual polar plates of proton exchange membrane fuel cell biscuit, and, do not see the research report of moulding specially-shaped cathode supporter 1400 ℃ of achievements in research of carrying out vacuum-sintering acquisition sintered body.Its gel rubber system that adopts is acrylamide (monomer), N-N ' methylene-bisacrylamide (crosslinking agent), and dispersant, initator and catalyst are respectively Tween80, ammonium persulfate and tetramethylethylenediamine.But, adopt gel injection-moulding to add in the technology bipolar plates process of vacuum-sintering hole, when actual fabrication, following several significant deficiency can appear: (a) biscuit dry run easy deformation, (b) carbonaceous mesophase spherules is owing to have self sintering matter, sintered body takes place to merge and formed in particle in sintering process, fusion has taken place in the hole behind the sintering, the fine pore is merged and has been formed macrovoid, and the sintering neck occurred, at sintering process easy deformation and cracking, (c) carbonaceous mesophase spherules, the high-temperature vacuum sintering can reach higher degree of graphitization more than 1800 ℃, can guarantee higher conductivity, but very high to equipment and technological requirement; Cryogenic vacuum sintering graphite degree is little, and conductivity is low, can not satisfy the requirement of fuel cell electrode high conductivity.In the documents and materials, solution to the problems described above is not proposed all.

Summary of the invention:

The object of the present invention is to provide a kind of cathode support body biscuit and sintered body not to produce the direct alcohol fuel cell profiled porous cathode support body forming anti-deformation method of distortion.

Technical solution of the present invention is:

A kind of direct alcohol fuel cell profiled porous cathode support body forming anti-deformation method is characterized in that: comprise the following steps: successively

One, make biscuit:

(1) in gel injection-moulding pulp preparation process, add carbonaceous mesophase spherules and graphite powder simultaneously and prepare slurry as the main body composition, both mass percents are: carbonaceous mesophase spherules 50～100%, graphite powder 0～50%;

(2) measure the slurry for preparing, pour in the vessel, adding initiator ammonium persulfate (its addition is the 0.02-0.4% of carbonaceous mesophase spherules and graphite powder gross mass) also stirs, add catalyst tetramethylethylenediamine (its addition is the 0.01-0.2% of carbonaceous mesophase spherules and graphite powder gross mass) then, after mixing, slurry is injected the mould of banding pattern core, and biscuit is taken out in the demoulding again;

(3) biscuit is put into ethanolic solution and carried out the liquid state drying, the concentration of alcohol scope is 80-90%, and be 2-24 hour liquid drying time;

(4) biscuit is taken out from ethanolic solution, alcohol liquid with the hot blast drying surface, then biscuit is put into and takes the heating drying of rolling on the heater,, then temperature is transferred to 140-160 ℃ of roll-drying to constant weight at first at 70-90 ℃ of roll-drying 15-30 minute;

Two, sintered body moulding:

(1) above-mentioned drying is good biscuit is put in the graphite crucible that graphite powder is housed, and sequences successively;

(2) with graphite powder space in the graphite crucible is filled up, compressed, put into burner hearth;

(3) with per hour 300 ℃ be rapidly heated to 600 ℃, be incubated 1 hour;

(4) be warming up to 800 ℃ with 100 ℃ of speed per hour;

(5) with after per hour 50 ℃ of speed are warming up to 1000 ℃, be incubated 2 hours, with the stove cooling, get product again.

Advantage of the present invention:

(1) is out of shape in order to produce in biscuit preparation of the special-shaped methanol fuel cell cathode supporter of the MCMB that prevents gel casting forming and the sintering process, the present invention has adopted (a) to add carbonaceous mesophase spherules simultaneously and graphite powder prepares slurry as the main body composition, (b) biscuit adopts and carries out the liquid state drying in the ethanolic solution, hot blast drying and low, the high temperature roll-drying and (c) the biscuit sintering process adopt special heat temperature raising, technology paths such as insulation route, thereby on the basis of satisfying the cathode support body performance requirement that is obtained, guarantee that cathode support body biscuit and sintered body do not produce distortion.

(2) the cathode support body sintering has adopted 1000 ℃ and following carbon burial sintering technology, and technology is simple, and sintering temperature is low, and needing no vacuum or inert gas shielding can either effectively prevent the distortion of high temperature sintering, have reduced manufacturing cost simultaneously.

(3) with the direct alcohol fuel cell profiled porous cathode support body of anti-deformation technology of the present invention preparation, can be circular, square etc., caliber is changeable, and can realize by change mould model.

(4) the anti-deformation technology of the present invention direct alcohol fuel cell profiled porous anode support that also can be used to prepare can be circular, square etc., and caliber is changeable, and can realize by changing the mould model.

(5) make special-shaped directly alcohol fuel battery with the direct alcohol fuel cell profiled porous cathode support body of anti-deformation technology of the present invention preparation, in light weight, volume is little, can fuel-in-storage, be easy to carry.

The utility model is described in further detail below in conjunction with embodiment:

Embodiment:

A kind of direct alcohol fuel cell profiled porous cathode support body forming anti-deformation method comprises the following steps: successively

One, make biscuit:

(1) in gel injection-moulding pulp preparation process, add carbonaceous mesophase spherules and graphite powder simultaneously and prepare slurry as the main body composition, both mass percents are: carbonaceous mesophase spherules 50～100% (example 50%, 70%, 100%), graphite powder 0～50% (example 50%, 30%, 0%);

(2) measure the slurry for preparing, pour in the vessel, adding initiator ammonium persulfate (its addition is the 0.02-0.4% of carbonaceous mesophase spherules and graphite powder gross mass) also stirs, add catalyst tetramethylethylenediamine (its addition is the 0.01-0.2% of carbonaceous mesophase spherules and graphite powder gross mass) then, after mixing, slurry is injected the mould of banding pattern core, and biscuit is taken out in the demoulding again;

(3) biscuit is put into ethanolic solution and carried out the liquid state drying, the concentration of alcohol scope is 80-90%, and be 2-24 hour (example 2,10,23 hours) liquid drying time;

(4) biscuit is taken out from ethanolic solution, alcohol liquid with the hot blast drying surface, then biscuit is put into and takes the heating drying of rolling on the heater, at first, then temperature is transferred to 140-160 ℃ of roll-drying to constant weight 70-90 ℃ of roll-drying 15-30 minute (example 15,25,30 minutes);

Two, sintered body moulding:

(1) above-mentioned drying is good biscuit is put in the graphite crucible that graphite powder is housed, and sequences successively;

(2) with graphite powder space in the graphite crucible is filled up, compressed, put into burner hearth;

(3) with per hour 300 ℃ be rapidly heated to 600 ℃, be incubated 1 hour;

(4) be warming up to 800 ℃ with 100 ℃ of speed per hour;

(5) with after per hour 50 ℃ of speed are warming up to 1000 ℃, be incubated 2 hours, with the stove cooling, get product again.

Claims (1)

1. a direct alcohol fuel cell profiled porous cathode support body forming anti-deformation method is characterized in that: comprise the following steps: successively

One, make biscuit:

(1) in gel injection-moulding pulp preparation process, add carbonaceous mesophase spherules and graphite powder simultaneously and prepare slurry as the main body composition, both mass percents are: 50%≤carbonaceous mesophase spherules＜100%, 0%＜graphite powder≤50%;

(2) measure the slurry for preparing, pour in the vessel, add initiator ammonium persulfate and also stir, add the catalyst tetramethylethylenediamine then, after mixing, slurry is injected the mould of banding pattern core, biscuit is taken out in the demoulding again;

(3) biscuit is put into ethanolic solution and carried out the liquid state drying, the concentration of alcohol scope is 80-90%, and be 2-24 hour liquid drying time;

(4) biscuit is taken out from ethanolic solution, alcohol liquid with the hot blast drying surface, then biscuit is put into and takes the heating drying of rolling on the heater,, then temperature is transferred to 140-160 ℃ of roll-drying to constant weight at first at 70-90 ℃ of roll-drying 15-30 minute;

Two, sintered body moulding:

(1) above-mentioned drying is good biscuit is put in the graphite crucible that graphite powder is housed, and sequences successively;

(2) with graphite powder space in the graphite crucible is filled up, compressed, put into burner hearth;

(3) with per hour 300 ℃ be rapidly heated to 600 ℃, be incubated 1 hour;

(4) be warming up to 800 ℃ with 100 ℃ of speed per hour;

(5) with after per hour 50 ℃ of speed are warming up to 1000 ℃, be incubated 2 hours, with the stove cooling, get product again.