JPH0326908B2 - - Google Patents
Info
- Publication number
- JPH0326908B2 JPH0326908B2 JP59039266A JP3926684A JPH0326908B2 JP H0326908 B2 JPH0326908 B2 JP H0326908B2 JP 59039266 A JP59039266 A JP 59039266A JP 3926684 A JP3926684 A JP 3926684A JP H0326908 B2 JPH0326908 B2 JP H0326908B2
- Authority
- JP
- Japan
- Prior art keywords
- water
- activated carbon
- gas diffusion
- repellent
- diffusion electrode
- 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
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 52
- 239000005871 repellent Substances 0.000 claims description 23
- 238000009792 diffusion process Methods 0.000 claims description 19
- 229920001343 polytetrafluoroethylene Polymers 0.000 claims description 13
- 239000004810 polytetrafluoroethylene Substances 0.000 claims description 13
- 238000004519 manufacturing process Methods 0.000 claims description 11
- 239000010419 fine particle Substances 0.000 claims description 9
- 238000000034 method Methods 0.000 claims description 6
- 239000006185 dispersion Substances 0.000 claims description 4
- 239000003054 catalyst Substances 0.000 claims description 3
- 238000003466 welding Methods 0.000 claims description 3
- 229920001577 copolymer Polymers 0.000 claims description 2
- HCDGVLDPFQMKDK-UHFFFAOYSA-N hexafluoropropylene Chemical group FC(F)=C(F)C(F)(F)F HCDGVLDPFQMKDK-UHFFFAOYSA-N 0.000 claims description 2
- 238000002844 melting Methods 0.000 claims description 2
- 230000008018 melting Effects 0.000 claims description 2
- 238000002156 mixing Methods 0.000 claims description 2
- -1 polytetrafluoroethylene Polymers 0.000 claims description 2
- 239000002245 particle Substances 0.000 claims 3
- BFKJFAAPBSQJPD-UHFFFAOYSA-N tetrafluoroethene Chemical group FC(F)=C(F)F BFKJFAAPBSQJPD-UHFFFAOYSA-N 0.000 claims 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 18
- 239000007789 gas Substances 0.000 description 14
- 230000002940 repellent Effects 0.000 description 11
- 238000003860 storage Methods 0.000 description 6
- 230000007774 longterm Effects 0.000 description 3
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 239000011230 binding agent Substances 0.000 description 2
- QLOAVXSYZAJECW-UHFFFAOYSA-N methane;molecular fluorine Chemical compound C.FF QLOAVXSYZAJECW-UHFFFAOYSA-N 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 238000003825 pressing Methods 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- PYVHTIWHNXTVPF-UHFFFAOYSA-N F.F.F.F.C=C Chemical compound F.F.F.F.C=C PYVHTIWHNXTVPF-UHFFFAOYSA-N 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000003792 electrolyte Substances 0.000 description 1
- 239000003350 kerosene Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Classifications
-
- 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
- Inert Electrodes (AREA)
Description
本発明は活性炭を撥水処理することにより、電
極の寿命を長くし、かつ電気抵抗の小さなガス拡
散電極の製造方法に関するものである。
従来から、空気電池等のガス拡散電極は、活性
炭、バインダー、撥水剤とを混合して使用してい
る。特開昭49−41830のように、バインダーと撥
水剤とを兼ねてポリテトラフルオロエチレン
（PTFE）粉末を用ちいるものであつた。空気電
池は貯蔵特性、高温高湿下での放電等において、
ガス拡散電極の撥水性が重要なポイントであつ
た。しかし、PTFEの量を多くするとガス拡散電
極のガス透過性が悪くなり作動電圧が低下し、さ
らに活性炭自体撥水処理されてないため、長期貯
蔵性が良好でなかつた。
また、液体もしくは固体撥水剤を溶剤に溶かし
て活性炭に含浸させ、溶剤を蒸発させる製造方法
もあつたが、撥水剤が活性炭の前表面を覆つてし
まい、ガス拡散電極の電気抵抗が大きくなるた
め、放電作動電圧が低くなつた。また撥水剤の量
を少なくすると充分な撥水効果が得られない欠点
があつた。
また、特開昭50−138344のように、撥水性物質
として、粉末状のフツ化黒鉛（CF）ｎを混合す
る製造方法もあつたが、ガス拡散電極の電気抵抗
が大きくなり放電作動電圧が低下したり、活性炭
自体撥水処理されていないため、活性炭表面が電
解液で濡れてしまい、長期貯蔵に耐えられない欠
点があつた。
本発明は撥水性の微粒子を活性炭表面に部分的
に溶着させることにより、ガス拡散電極の電気抵
抗、触媒能力を劣化せしめず撥水性を持たせ、長
期貯蔵特性を向上させるものである。
本発明の実施例の製造方法を説明する。
まず、活性炭もしくは触媒を吸着した活性炭
100ｇを水１に分散せしめ、次に径0.01〜50μの
PTFEの60重量％の水性分散液を、水で10倍にう
すめる。活性炭分散液を撹拌しながらPTFE分散
液を100ml滴下する。この量はPTFE固形分と活
性炭との重量比が、活性炭を100とすると、0.1：
100〜40：100の間で良好な結果が得られる。使用
する活性炭の種類によつて上記範囲内で適宜調節
して用いる。次に上記の混合液を30分撹拌して、
活性炭表面にPTFEの微粒子を吸着させ、活性炭
を過乾燥する。さらに、PTFEの融点以上の温
度380℃〜400℃で30分加熱し、活性炭表面に
PTFEを溶かして溶着せしめる。溶着は活性炭全
面を覆うのでなく、活性炭を部分的に撥水化させ
るため、酸素還元触媒の作用する表面は充分残し
ている。このようにして撥水処理した活性炭80重
量％とPTFE粉20重量％とを混合し、ローラーに
よりシート化し、ニツケルネツトを圧着し、さら
にPTFEフイルムを圧着して、ガス拡散電極を製
造するものである。
上記のガス拡散電極を用いて試作した本発明に
よるPR44型空気電池〔Ａ〕と、比較のため、撥
水処理をしない活性炭を使用したガス拡散電極を
用いた同型の従来空気電池〔Ｂ〕、灯油により撥
水処理した活性炭を使用したガス拡散電極を用い
た同型の従来空気電池〔Ｃ〕とを試作し、初度の
電池の内部抵抗、0.9Vまでの放電容量、60％放
電時の放電作動電圧を表１に、温度45℃、湿度60
％で空気孔を開放して１ケ月貯蔵後の電池の放電
容量と放電作動電圧とを表２に、電池〔Ａ〕、
〔Ｂ〕、〔Ｃ〕とを比較して示した。
The present invention relates to a method for manufacturing a gas diffusion electrode that extends the life of the electrode and has low electrical resistance by treating activated carbon to be water-repellent. BACKGROUND ART Conventionally, gas diffusion electrodes for air batteries and the like have used a mixture of activated carbon, a binder, and a water repellent. As in JP-A-49-41830, polytetrafluoroethylene (PTFE) powder was used as both a binder and a water repellent. Air batteries have poor storage characteristics, discharge under high temperature and high humidity, etc.
The water repellency of the gas diffusion electrode was an important point. However, when the amount of PTFE was increased, the gas permeability of the gas diffusion electrode deteriorated and the operating voltage decreased, and furthermore, since the activated carbon itself was not water-repellent treated, the long-term storage property was not good. Another manufacturing method was to dissolve a liquid or solid water repellent in a solvent, impregnate activated carbon, and then evaporate the solvent, but the water repellent covered the front surface of the activated carbon, increasing the electrical resistance of the gas diffusion electrode. As a result, the discharge operating voltage became lower. In addition, if the amount of water repellent is reduced, a sufficient water repellent effect cannot be obtained. In addition, as in JP-A-50-138344, there was a manufacturing method in which powdered graphite fluoride (CF) was mixed as a water-repellent substance, but this increased the electrical resistance of the gas diffusion electrode and lowered the discharge operating voltage. However, since the activated carbon itself is not water-repellent, the surface of the activated carbon gets wet with the electrolyte, making it unable to withstand long-term storage. The present invention provides water repellency to the gas diffusion electrode without deteriorating its electrical resistance and catalytic ability by partially welding water-repellent fine particles to the surface of activated carbon, thereby improving long-term storage characteristics. A manufacturing method of an embodiment of the present invention will be explained. First, activated carbon or activated carbon that has adsorbed a catalyst
Disperse 100g in 1 part of water, then add a
A 60% by weight aqueous dispersion of PTFE is diluted 10 times with water. Drop 100 ml of the PTFE dispersion into the activated carbon dispersion while stirring. This amount is 0.1, assuming that the weight ratio of PTFE solid content to activated carbon is 100:
Good results are obtained between 100 and 40:100. The amount is appropriately adjusted within the above range depending on the type of activated carbon used. Next, stir the above mixture for 30 minutes,
Fine particles of PTFE are adsorbed onto the activated carbon surface, and the activated carbon is overdried. Furthermore, the activated carbon surface was heated for 30 minutes at a temperature of 380℃ to 400℃, which is higher than the melting point of PTFE.
Melt and weld the PTFE. The welding does not cover the entire surface of the activated carbon, but rather makes the activated carbon partially water repellent, leaving enough surface area for the oxygen reduction catalyst to act. A gas diffusion electrode is manufactured by mixing 80% by weight of activated carbon treated with water repellency in this way and 20% by weight of PTFE powder, forming it into a sheet using a roller, pressing a nickel net, and then pressing a PTFE film. . PR44 type air battery according to the present invention prototyped using the above gas diffusion electrode [A], and for comparison, a conventional air battery of the same type using a gas diffusion electrode using activated carbon without water repellent treatment [B], We prototyped a conventional air battery [C] of the same type using a gas diffusion electrode made of activated carbon treated to make it water repellent with kerosene, and measured the initial battery internal resistance, discharge capacity up to 0.9V, and discharge operation at 60% discharge. The voltage is shown in Table 1, the temperature is 45℃, and the humidity is 60℃.
Table 2 shows the discharge capacity and discharge operating voltage of the batteries after storage for one month with the air holes opened at 100%.
A comparison between [B] and [C] is shown.
【表】【table】
【表】
表１、２の結果から、本発明品は撥水剤を用い
ているが、同剤を用いない従来電池〔Ｂ〕と電池
内部抵抗が同じであり、特に貯蔵後の結果が放電
容量と放電作動電圧共に従来品〔Ｂ〕、〔Ｃ〕より
優れていることがわかる。
上記実施例では撥水剤としてPTFEを用いたガ
ス拡散電極について記したが、この他に４フツ化
エチレンと６フツ化プロピレンとの共重合体のフ
ツ素系樹脂等の撥水性を有する微粒子を用いて
も、同様な製造方法で優れた結果を得ることがで
きる。
以上のように、本発明は撥水性を有し貯蔵特性
を向上し、合せて電池内部抵抗を小さくし、すぐ
れたガス拡散電極を得ることができる。[Table] From the results in Tables 1 and 2, the product of the present invention uses a water repellent, but the internal resistance of the battery is the same as that of the conventional battery [B] that does not use the same agent. It can be seen that both capacity and discharge operating voltage are superior to conventional products [B] and [C]. In the above example, a gas diffusion electrode using PTFE as a water repellent was described, but in addition to this, fine particles having water repellency such as a fluororesin made of a copolymer of ethylene tetrafluoride and propylene hexafluoride were used. Excellent results can be obtained using similar manufacturing methods. As described above, the present invention can provide an excellent gas diffusion electrode that has water repellency, improves storage characteristics, and reduces internal battery resistance.
Claims (1)
水性の微粒子を混合もしくは付着させた後、該微
粒子の融点以上の温度で加熱し、撥水性の微粒子
を部分的に活性炭表面に溶着せしめるガス拡散電
極の製造方法。 ２ 該撥水性の微粒子を活性炭に混合もしくは付
着させる方法が、撥水性の微粒子の分散液を用い
ることを特徴とする特許請求の範囲第１項記載の
ガス拡散電極の製造方法。 ３ 該撥水性の微粒子が、フツ素系樹脂であるこ
とを特徴とする特許請求の範囲第１項または第２
項記載のガス拡散電極の製造方法。 ４ 該フツ素系樹脂が、ポリテトラフルオロエチ
レン、４フツ化エチレンと６フツ化プロピレンと
の共重合体であることを特徴とする特許請求の範
囲第３項記載のガス拡散電極の製造方法。 ５ 該撥水性の微粒子が、0.01μ〜50μの粒度を有
していることを特徴とする特許請求の範囲第１
項、第２項または第３項記載のガス拡散電極の製
造方法。 ６ 該撥水性の微粒子が、活性炭との重量比で活
性炭を100とすると0.1：100〜40：100であること
を特徴とする特許請求の範囲第１項、第２項、第
３項、第５項記載のガス拡散電極の製造方法。[Claims] 1. After water-repellent fine particles are mixed or attached to activated carbon or activated carbon that has adsorbed a catalyst, the water-repellent fine particles are heated at a temperature higher than the melting point of the fine particles to partially cover the surface of the activated carbon. A method for manufacturing gas diffusion electrodes by welding. 2. The method for producing a gas diffusion electrode according to claim 1, wherein the method for mixing or adhering the water-repellent particles to activated carbon uses a dispersion of water-repellent particles. 3. Claim 1 or 2, characterized in that the water-repellent fine particles are a fluororesin.
The method for manufacturing the gas diffusion electrode described in Section 1. 4. The method for producing a gas diffusion electrode according to claim 3, wherein the fluororesin is polytetrafluoroethylene or a copolymer of tetrafluoroethylene and hexafluoropropylene. 5. Claim 1, wherein the water-repellent fine particles have a particle size of 0.01μ to 50μ.
The method for manufacturing a gas diffusion electrode according to item 2, item 2, or item 3. 6. Claims 1, 2, 3, and 6, characterized in that the water-repellent fine particles have a weight ratio of 0.1:100 to 40:100 when activated carbon is 100. The method for manufacturing a gas diffusion electrode according to item 5.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59039266A JPS60186490A (en) | 1984-03-01 | 1984-03-01 | Manufacture of gas diffusion electrode |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59039266A JPS60186490A (en) | 1984-03-01 | 1984-03-01 | Manufacture of gas diffusion electrode |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60186490A JPS60186490A (en) | 1985-09-21 |
| JPH0326908B2 true JPH0326908B2 (en) | 1991-04-12 |
Family
ID=12548335
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP59039266A Granted JPS60186490A (en) | 1984-03-01 | 1984-03-01 | Manufacture of gas diffusion electrode |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60186490A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62110259A (en) * | 1985-11-07 | 1987-05-21 | Fuji Electric Co Ltd | Manufacture of gas diffusing electrode for fuel battery |
| JP2689300B2 (en) * | 1993-02-02 | 1997-12-10 | 岩崎電気株式会社 | Fluorescent lamp crushing device |
| US20050130025A1 (en) | 2002-01-11 | 2005-06-16 | Tetsuji Kadowaki | Carbonaceous material and dispersion containing the same |
-
1984
- 1984-03-01 JP JP59039266A patent/JPS60186490A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60186490A (en) | 1985-09-21 |
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