JPH0315305B2 - - Google Patents
Info
- Publication number
- JPH0315305B2 JPH0315305B2 JP57047996A JP4799682A JPH0315305B2 JP H0315305 B2 JPH0315305 B2 JP H0315305B2 JP 57047996 A JP57047996 A JP 57047996A JP 4799682 A JP4799682 A JP 4799682A JP H0315305 B2 JPH0315305 B2 JP H0315305B2
- Authority
- JP
- Japan
- Prior art keywords
- gas
- fuel cell
- matrix
- phosphoric acid
- electrolyte
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/30—Hydrogen technology
- Y02E60/50—Fuel cells
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Sustainable Development (AREA)
- Sustainable Energy (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Fuel Cell (AREA)
Description
【発明の詳細な説明】
この発明は、電解液としてりん酸を保持したマ
トリツクスと、該マトリツクスに連通して設けら
れた前記電解液のリザーバとを有するりん酸型の
燃料電池（以下、電解液固定型燃料電池という）
において、燃料電池のマトリツクス（電解液保持
部材）中の電解質の晶析（結晶の析出）を防止さ
せる方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention provides a phosphoric acid fuel cell (hereinafter referred to as "electrolytic solution") having a matrix holding phosphoric acid as an electrolytic solution and a reservoir for the electrolytic solution provided in communication with the matrix. (called stationary fuel cell)
The present invention relates to a method for preventing crystallization (crystal precipitation) of an electrolyte in a fuel cell matrix (electrolyte holding member).
燃料ガスとして水素ガスまたはメタン、エタン
等の天然ガスを改質した改質水素ガスを用い、酸
化剤ガスとして酸素ガスまたは空気を用いる電解
液固定型燃料電池においては、電池内部での反応
ガスの混合（主に、電極触媒面からマトリツクス
を通過し対極へ到達するガス洩れ）を防止する役
割をマトリツクスにもたせることが望ましい。こ
のマトリツクスはりん酸等の電解液を保持した状
態で高いガスふきぬけ圧力（0.5〜２Kg／cm2）を
有しなければならない。 In fixed electrolyte fuel cells that use hydrogen gas or reformed hydrogen gas obtained by reforming natural gas such as methane or ethane as the fuel gas and oxygen gas or air as the oxidant gas, the reaction gas inside the cell is It is desirable that the matrix has the role of preventing mixing (mainly gas leakage from the electrode catalyst surface through the matrix and reaching the counter electrode). This matrix must have a high gas blowing pressure (0.5 to 2 kg/cm 2 ) while retaining an electrolyte such as phosphoric acid.
電解液固定型燃料電池は、一般に第１図に示す
構成を有する。すなわち燃料電池１は、耐熱性、
耐蝕性および電気絶縁性を有する多孔性薄膜部材
にりん酸などの電解液を含浸させたマトリツクス
２と、前記マトリツクスにより隔置されたガス拡
散および電解液浸透性を有する多孔性の燃料電極
（水素電極）３および酸化剤電極（酸素電極また
は空気電極）４と、これら電極のガス側基材に接
触し集電の役割を果すとともに、それぞれの電極
へ反応ガスを供給するためのガス区画室５，６と
電解液用のリザーバ９を形成するセパレータプレ
ート（バイポーラプレート）７，８とから成立つ
ている。 A fixed electrolyte fuel cell generally has the configuration shown in FIG. That is, the fuel cell 1 has heat resistance,
A matrix 2 is formed by impregnating a porous thin film member with corrosion resistance and electrical insulation with an electrolyte such as phosphoric acid, and a porous fuel electrode (hydrogen electrode) 3 and oxidizer electrode (oxygen electrode or air electrode) 4, and a gas compartment 5 that contacts the gas side base material of these electrodes and plays the role of current collection, as well as supplying reaction gas to each electrode. , 6 and separator plates (bipolar plates) 7, 8 forming a reservoir 9 for electrolyte.
電極は、ガスの拡散または透過を用意にするた
めの多孔性カーボン不織布基材３ａ，４ａ上にグ
ラフフアイト粉末をポリテトラフルオロエチレン
（PTFE）で結合させた薄膜（撥水層）３ｂ，４
ｂと電極反応を容易に行なわせるための貴金属を
担持したカーボン粉末触媒をPTFEで結合させた
薄層（触媒層）３ｃ，４ｃより構成されている。 The electrodes are thin films (water repellent layers) 3b, 4 in which graphite powder is bonded with polytetrafluoroethylene (PTFE) on porous carbon nonwoven fabric substrates 3a, 4a to facilitate gas diffusion or permeation.
It is composed of thin layers (catalyst layers) 3c and 4c in which a carbon powder catalyst supporting a noble metal is bonded with PTFE to facilitate the electrode reaction with b.
マトリツクス２は耐熱・耐蝕性・非電導性を有
する微粉末を少量のPTFEで結合させた薄膜であ
る。前記マトリツクスには、○イ電解液に高湿潤
性、○ロ大きな電解液保持力○ハ高いガスふきぬけ圧
力○ニ機械的強度が大きい事などの特性を有するこ
とが望まれる。 Matrix 2 is a thin film made of heat-resistant, corrosion-resistant, and non-conductive fine powder bonded with a small amount of PTFE. It is desired that the matrix has the following characteristics: (a) high wettability with the electrolyte, (b) large electrolyte retention ability, (c) high gas bleed pressure, and (d) high mechanical strength.
かかる燃料電池において、電解液としてりん酸
が使用される場合には、マトリツクスに含浸させ
るりん酸は一般に95〜100wt％の濃度のものが使
用され、通常の運転条件下（温度150〜200℃）で
はマトリツクス中に保持されているりん酸の濃度
は100〜105wt％となる。ところで前記濃度にり
ん酸は第３図に示されたような氷晶温度を有す
る。縦軸は温度、横軸は濃度である。すなわちり
ん酸濃度100wt％で氷晶温度は約42℃、102wt％
で約35℃、105wt％で約30℃となる。このような
氷晶温度を有する濃度のりん酸を保持したマトリ
ツクスからなる燃料電池を休止状態（電池の温度
が大気に等しい温度状態で運転休止する）に報知
した場合には、マトリツクスおよび電極触媒層反
応界面に保持されたりん酸は氷晶温度以下であ
り、結晶析出が起る。りん酸に漏れやすくしかも
りん酸の保持力を高めるために撥水性を有する
PTFE結合剤を可能な限り少ない量で作製してい
るマトリツクスにおいて、このりん酸の結晶析出
が起ると、マトリツクス膜に亀裂および層間剥離
および構造破壊などをもたらし、○イ電解液保持力
の低下○ロ絶縁抵抗の低下○ハマトリツクス強度の低
下○ニ電池内部での反応ガスの漏洩および混合など
に伴う電池性能低下の原因となる。 In such fuel cells, when phosphoric acid is used as the electrolyte, the phosphoric acid impregnated into the matrix is generally used at a concentration of 95 to 100 wt%, and under normal operating conditions (temperature 150 to 200°C). In this case, the concentration of phosphoric acid retained in the matrix is 100 to 105 wt%. By the way, phosphoric acid at the above concentration has an ice crystal temperature as shown in FIG. The vertical axis is temperature and the horizontal axis is concentration. In other words, when the phosphoric acid concentration is 100wt%, the ice crystal temperature is approximately 42℃, 102wt%.
It becomes about 35℃ at 105wt%, and about 30℃ at 105wt%. When a fuel cell made of a matrix containing phosphoric acid at a concentration having such an ice crystal temperature is placed in a dormant state (operation is stopped with the cell temperature equal to that of the atmosphere), the matrix and electrode catalyst layer The phosphoric acid retained at the reaction interface is below the ice crystal temperature, and crystal precipitation occurs. Easily leaks into phosphoric acid, yet has water repellency to increase phosphoric acid retention
When this phosphoric acid crystal precipitation occurs in a matrix made with the smallest possible amount of PTFE binder, it causes cracks, delamination, and structural destruction in the matrix film, resulting in a decrease in electrolyte retention ability. ○ Decrease in insulation resistance ○ Decrease in hamatrix strength ○ Cause deterioration in battery performance due to leakage and mixing of reactive gases inside the battery.
この発明は前述の欠点を除去して、マトリツク
ス膜の秀れた電解液保持力および耐ガス圧性等の
特性が損われないような運転休止方法を提供する
ことを目的とする。 The object of the present invention is to eliminate the above-mentioned drawbacks and to provide a method for shutting down operations in which the excellent properties of the matrix membrane, such as electrolyte holding power and gas pressure resistance, are not impaired.
第２図はこの発明の実施例を示すもので、燃料
電池１０は燃料電極１３と酸化剤電極１４とこれ
ら電極を隔離し電解液区画室を形成するマトリツ
クス１２およびそれぞれの電極へ反応ガスを供給
するためのガス区画室１５および１６より構成さ
れている。このような構成を有する燃料電池にお
いて、電池の運転時には、燃料ガスは燃料供給バ
ルブ１７および流量計１８を経由し、ガス区画室
１５へ供給され、燃料排出バルブ１９より排出さ
れる。一方、酸化剤ガスは酸化剤供給バルブ２０
および流量計２１を経由し、ガス区画室１６へ供
給され、酸化剤排出バルブ２２へ排出される。 FIG. 2 shows an embodiment of the present invention, in which a fuel cell 10 includes a fuel electrode 13, an oxidizer electrode 14, a matrix 12 that isolates these electrodes and forms an electrolyte compartment, and supplies a reactive gas to each electrode. It consists of gas compartments 15 and 16 for the purpose of In a fuel cell having such a configuration, during operation of the cell, fuel gas is supplied to the gas compartment 15 via the fuel supply valve 17 and the flow meter 18, and is discharged from the fuel discharge valve 19. On the other hand, the oxidant gas is supplied by the oxidant supply valve 20
The gas is supplied to the gas compartment 16 via the flow meter 21 and discharged to the oxidizer discharge valve 22.
しかして、運転停止直後には、燃料ガス系統お
よび酸化剤ガス系統および酸化剤ガス系統のそれ
ぞれの供給バルブ１７，２０を閉じ、N2（窒素）
ガス調湿器入口、出口バルブ２４，２５およびバ
ルブ２６を開き、調湿器２３により一定の湿度に
コントロールされたN2ガスを供給する。この湿
潤N2ガスにより、りん酸に水を吸湿させ濃度を
75wt％まで下げる。たとえば50℃で湿度28％の
ガスを送つてやれば、運転湿度（170℃〜190℃）
で約105wt％であつたりん酸は、50℃で約75wt％
となる。その後20℃まで温度を下げて75±5wt％
の濃度を保つためには20℃で48〜22％の湿度のガ
スを送る必要がある。第３図より75wt％付近で
は、りん酸の氷晶点は約−20℃であり、この濃度
まで下がれば、マトリツクス膜および電極触媒層
反応界面に保持されたりん酸は結晶して析出する
ことはない。また100wt％のりん酸を75wt％にす
れば、体積は1.33倍となり、この容積増加分は第
１図のセパレータプレート７にマトリツクスと連
通して設けたリザーバ９に吸収される。このリザ
ーバは、再起動後のりん酸の濃縮による容積減少
にともない、電解液をすみやかに、マトリツクス
膜および電解触媒反応界面に移動せしめる程度の
電解液保持力を有するものである。 Immediately after the operation is stopped, the supply valves 17 and 20 of the fuel gas system, oxidizing gas system, and oxidizing gas system are closed, and N 2 (nitrogen) is
The gas humidifier inlet, outlet valves 24, 25, and valve 26 are opened, and N 2 gas whose humidity is controlled by the humidifier 23 is supplied. This wet N2 gas causes phosphoric acid to absorb water and increase its concentration.
Reduce to 75wt%. For example, if you send gas at 50°C and 28% humidity, the operating humidity (170°C to 190°C)
Phosphoric acid, which is about 105wt% at 50℃, is about 75wt% at 50℃
becomes. After that, lower the temperature to 20℃ to 75±5wt%
In order to maintain the concentration of , it is necessary to send gas at 20°C and a humidity of 48 to 22%. As shown in Figure 3, the freezing point of phosphoric acid is approximately -20℃ at around 75wt%, and if the concentration drops to this concentration, the phosphoric acid retained at the reaction interface of the matrix membrane and electrode catalyst layer will crystallize and precipitate. There isn't. Further, if 100 wt% phosphoric acid is changed to 75 wt%, the volume increases by 1.33 times, and this increase in volume is absorbed by the reservoir 9 provided in the separator plate 7 of FIG. 1 in communication with the matrix. This reservoir has enough electrolyte holding power to quickly move the electrolyte to the matrix membrane and the electrocatalytic reaction interface as the volume decreases due to concentration of phosphoric acid after restart.
なお、りん酸を十分に湿潤させたのちは、バル
ブ２４，２５は閉じられ、バルブ２６，２７およ
び２８ならびに図示しないベント弁を開いて、燃
料電池の各区画室をN2ガスでパージする。以上
述べたように、この発明によれば、マトリツクス
タイプの電解液固定型燃料電池において、マトリ
ツクス膜および電極触媒反応界面に保持された電
解液の濃度を、燃料ガス系統および酸化剤ガス系
統の少なくとも一方に送る湿潤したガスにより下
げるようにしたため、運転休止中の電解質の結晶
析出を防止でき、マトリツクス膜の亀裂層間剥離
等が生じなくなり、電解液保持力の低下、絶縁抵
抗の低下、マトリツクス強度の低下ならびに電池
内部での反応ガスの漏洩および混合等に伴う電池
性能低下原因を除去することができる。 After sufficiently moistening the phosphoric acid, valves 24 and 25 are closed, valves 26, 27, and 28 and a vent valve (not shown) are opened to purge each compartment of the fuel cell with N 2 gas. As described above, according to the present invention, in a matrix type fixed electrolyte fuel cell, the concentration of the electrolyte retained at the matrix membrane and the electrode catalyst reaction interface is controlled by the fuel gas system and the oxidant gas system. Since it is lowered by moist gas sent to at least one side, it is possible to prevent electrolyte crystal precipitation during suspension of operation, and prevent cracks and delamination of the matrix membrane, resulting in a decrease in electrolyte holding power, a decrease in insulation resistance, and matrix strength. It is possible to eliminate causes of deterioration in battery performance due to a decrease in battery performance and leakage and mixing of reactive gases inside the battery.
第１図は本発明の適用可能な燃料電池の要部断
面図、第２図は本発明の実施例の流体回路図、第
３図はりん酸の氷晶温度を説明するための特性線
図である。
１０……燃料電池、１５，１６……ガス区画
室、２３……窒素ガス調湿器。
Fig. 1 is a sectional view of essential parts of a fuel cell to which the present invention can be applied, Fig. 2 is a fluid circuit diagram of an embodiment of the present invention, and Fig. 3 is a characteristic line diagram for explaining the ice crystal temperature of phosphoric acid. It is. 10... Fuel cell, 15, 16... Gas compartment, 23... Nitrogen gas humidifier.
Claims (1)
と、該マトリツクスに連通して設けられた前記電
解液のリザーバとを有するりん酸型の燃料電池に
おいて、燃料電池の運転休止時に、酸化剤ガス系
統側または燃料ガス系統側の少なくとも一方か
ら、燃料電池に湿潤ガスを供給することを特徴と
する燃料電池の運転方法。 ２ 特許請求の範囲第１項記載の方法において、
湿潤ガスは調湿した窒素ガスであることを特徴と
する燃料電池の運転方法。 ３ 特許請求の範囲第１項記載の方法において、
湿潤ガスは調湿した空気であることを特徴とする
燃料電池の運転方法。 ４ 特許請求の範囲第１項記載の方法において、
湿潤ガスは調湿した燃料であることを特徴とする
燃料電池の運転方法。[Scope of Claims] 1. In a phosphoric acid fuel cell having a matrix holding phosphoric acid as an electrolyte and a reservoir for the electrolyte provided in communication with the matrix, when the fuel cell is out of operation, A method of operating a fuel cell, comprising supplying humid gas to the fuel cell from at least one of an oxidizing gas system and a fuel gas system. 2. In the method described in claim 1,
A fuel cell operating method characterized in that the humid gas is nitrogen gas with controlled humidity. 3. In the method described in claim 1,
A fuel cell operating method characterized in that the humid gas is humidified air. 4. In the method described in claim 1,
A method of operating a fuel cell, characterized in that the humid gas is fuel with controlled humidity.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57047996A JPS58164162A (en) | 1982-03-25 | 1982-03-25 | Operation stopping method of fuel cell |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57047996A JPS58164162A (en) | 1982-03-25 | 1982-03-25 | Operation stopping method of fuel cell |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS58164162A JPS58164162A (en) | 1983-09-29 |
| JPH0315305B2 true JPH0315305B2 (en) | 1991-02-28 |
Family
ID=12790921
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP57047996A Granted JPS58164162A (en) | 1982-03-25 | 1982-03-25 | Operation stopping method of fuel cell |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS58164162A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2558636B2 (en) * | 1986-05-31 | 1996-11-27 | 株式会社東芝 | How to operate a fuel cell |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1513130A (en) * | 1974-11-18 | 1978-06-07 | Exxon Research Engineering Co | Fuel cells and methods of operating them |
| JPS5519712A (en) * | 1978-07-28 | 1980-02-12 | Fuji Electric Co Ltd | Stopping method of fuel cell |
-
1982
- 1982-03-25 JP JP57047996A patent/JPS58164162A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS58164162A (en) | 1983-09-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Hwang et al. | Influence of properties of gas diffusion layers on the performance of polymer electrolyte-based unitized reversible fuel cells | |
| WO1998031062A1 (en) | Surface replica fuel cell for micro fuel cell electrical power pack | |
| JP4072707B2 (en) | Solid polymer electrolyte fuel cell power generator and its operation method | |
| WO2002073721A1 (en) | Gas diffusion electrode and fuel cell using this | |
| CN110797546A (en) | Microporous layer structure, preparation method, membrane electrode assembly and fuel cell | |
| JP2002289230A (en) | Polymer electrolyte fuel cell | |
| JP2001297784A (en) | Stacked fuel cell system | |
| JPWO2002047190A1 (en) | Polymer electrolyte fuel cell and method of operating the same | |
| CN100508266C (en) | Membrane electrode unit | |
| KR100439814B1 (en) | Apparatus and method for operation of a polymer electrolyte membrane fuel cell below the freezing temperature of water | |
| JP2003109604A (en) | Gas diffusion electrode for fuel cell and method for producing the same | |
| JP4129366B2 (en) | Proton conductor manufacturing method and fuel cell manufacturing method | |
| JP2005158298A (en) | Operation method of fuel cell power generation system and fuel cell power generation system | |
| JP4880131B2 (en) | Gas diffusion electrode and fuel cell using the same | |
| JP4665353B2 (en) | Solid polymer electrolyte fuel cell power generator and its operation method | |
| JP2003059494A (en) | Operation method and fuel cell apparatus of polymer electrolyte fuel cell | |
| Liu et al. | Gold‐plated Ni mesh as the gas diffusion medium for air‐breathing direct methanol fuel cell | |
| JPH0315305B2 (en) | ||
| JPS6341192B2 (en) | ||
| CN116936874A (en) | Fast activation method of fuel cell stack | |
| JP2005267902A (en) | Polymer electrolyte fuel cell | |
| JPS60258863A (en) | Fuel cell | |
| JPH0622153B2 (en) | How to operate a fuel cell | |
| CN108390083B (en) | A method for starting the discharge working mode of a combined regenerative fuel cell system | |
| Ito et al. | Effect of titanium powder loading in microporous layer on a polymer electrolyte unitized reversible fuel cell |