JPS60218768A - Air cell - Google Patents

Abstract

PURPOSE:To make possible to take out high current by using activated carbon powder and conductive carbon powder as a positive electrode catalyst layer. CONSTITUTION:Activated carbon and conductive carbon such as acetylene black or graphite are used in a powder state as a positive electrode catalyst layer 5 without use of a binder. The powder-state positive electrode layer 5 has a 4-5 fold specific surface area and 9-10 fold hydrogen peroxide decomposition ability compared with a sheet-shaped positive electrode catalyst layer. Therefore, air diffusion is made easy and high current can be taken out by catalytic ability of activated carbon alone. By applying water repellent treatment to activated carbon and acetylene black or activated carbon and graphite, or moreover by adding a catalyst to them, effect is substantially increased.

Description

【発明の詳細な説明】 ・　本発明は、空気電池に関し、更に詳しくは。[Detailed description of the invention] - The present invention relates to an air battery, and more specifically.

大電流が取シ出せる小型空気電池に関するものである。This relates to a small air battery that can draw a large current.

従来、空気電池の電極は触媒を添加した活性炭及びアセ
チレンブラック、黒鉛などの導電性炭素をポリ四弗化エ
チレンなどを結着剤としてニッケルスクリーンなどの芯
材に充填しシート状に成形して正極触媒層としていた。Conventionally, the electrodes of air batteries are made by filling a core material such as a nickel screen with activated carbon containing a catalyst, acetylene black, graphite, or other conductive carbon using polytetrafluoroethylene as a binder and forming it into a sheet to form the positive electrode. It was used as a catalyst layer.

しかし、シート状に成形するためのポリ四弗化エチレン
などの結着剤を使用しているので。However, it uses a binder such as polytetrafluoroethylene to form it into a sheet.

正極触媒層としての表面積が非常に小さく正極触媒層内
での空気拡散が遅くなる。The surface area of the positive electrode catalyst layer is very small, and air diffusion within the positive electrode catalyst layer is slow.

そのため取シ出せる電流が小さくなる欠点を有していた
。Therefore, it has the disadvantage that the current that can be extracted is small.

この欠点を補なうために白金、バラジクム。Platinum and Balazicum to compensate for this deficiency.

銀などの貴金属触媒を使用していたが、触媒が高価なた
め電池自体のコストアップにつながっていた。Precious metal catalysts such as silver were used, but the expensive catalysts led to an increase in the cost of the battery itself.

本発明は、粉末状の活性炭と粉末状の導電性炭素とを正
極触媒層に使用することで大電流が取シ出せるようにし
た空気電池である。The present invention is an air battery that can draw a large current by using powdered activated carbon and powdered conductive carbon in the positive electrode catalyst layer.

即ち、活性炭とアセチレンブラック、黒鉛などの導電性
炭素とを結着剤を使用せず粉末状態で使用するのである
。That is, activated carbon and conductive carbon such as acetylene black or graphite are used in powder form without using a binder.

本発明の粉末状の正極触媒層は、一般のシート状の正極
触媒層に比較して比表面積で４〜５倍、更に過酸化水素
分解能で９〜１０倍である。The powdered positive electrode catalyst layer of the present invention has a specific surface area 4 to 5 times larger than that of a general sheet-shaped positive electrode catalyst layer, and further has a hydrogen peroxide decomposition capacity 9 to 10 times larger.

この為、シート状の正極触媒層に比較して空気拡散が非
常に容易になシ、活性炭の触媒能だけでも十分大きな電
流が取り出せることが可能となった。Therefore, compared to a sheet-shaped positive electrode catalyst layer, air diffusion is much easier, and a sufficiently large current can be extracted from the catalytic ability of activated carbon alone.

尚、活性炭やアセチレンブラック、黒鉛などに撥水処理
を施こしたシ、更に触媒を添加することＫよシ、よシ一
層の効果をあげることができる。In addition, even better effects can be obtained by applying water-repellent treatment to activated carbon, acetylene black, graphite, etc., and by adding a catalyst.

以下、実施例、比較例、基づき本発明の詳細な説明する
。Hereinafter, the present invention will be described in detail based on Examples and Comparative Examples.

〈正極触媒層〉 ヤシガラ活性炭の重量当シカスチレンの５％キシレン溶
液で撥水処理を施こし、このヤシガラ活性炭と同量のア
セチレンブラックをボールミルで粉砕混合してこの粉末
状物をニッケルスクリーン上に充填して実施例１用の正
極触媒層を得た。<Cathode catalyst layer> Water-repellent treatment is performed with a 5% xylene solution of cica styrene based on the weight of the coconut shell activated carbon, and the same amount of acetylene black as the coconut shell activated carbon is ground and mixed in a ball mill, and this powder is filled on a nickel screen. Thus, a positive electrode catalyst layer for Example 1 was obtained.

く正極触媒層〉 同重量のヤシガラ活性炭とアセチレンブラックをボール
ミルで粉砕混合して、この粉末状物をスチレンの５％キ
シレン溶液で撥水処理を施し、ニッケルスクリーン上に
充填して実施例２用の正極触媒層を得た。Positive electrode catalyst layer〉 Equal weights of coconut shell activated carbon and acetylene black were ground and mixed in a ball mill, and this powder was water-repellent treated with a 5% xylene solution of styrene, and filled on a nickel screen to prepare the powder for Example 2. A positive electrode catalyst layer was obtained.

く正極触媒層〉 同重量のヤシガラ活性炭とアセチレンブラックをボール
ミルで粉砕混合して、この粉末状物とポリ四弗化エチレ
ン水性ディスパージョンで混練し、ホットプレスを使用
し、ニッケルスクリーンとともにシート状に成形して比
較例用の正極触媒層を得た。Positive electrode catalyst layer〉 Equal weights of coconut shell activated carbon and acetylene black are pulverized and mixed in a ball mill, and this powder is kneaded with an aqueous polytetrafluoroethylene dispersion, and then formed into a sheet with a nickel screen using a hot press. A positive electrode catalyst layer for a comparative example was obtained by molding.

上述した正極触媒層を使用して図面と同様な１ｔ４４タ
イプの空気電池を試作した。A 1t44 type air cell similar to the one shown in the drawing was prototyped using the above-mentioned positive electrode catalyst layer.

底面が平坦な正極ケース１の底面に空気流入孔２を設け
、正極ケース１の底部に空気拡散紙３を配置する。この
空気拡散紙３は耐アルカリ性のものであれば良く１本実
施例ではアルカリセルローズを使用したが、フッ素樹脂
粉末などで撥水処理したものであってもよい。空気拡散
紙３の上部には撥水膜４を配置しているが、前記した空
気拡散紙３の外径よシ撥水膜４の外径を大としたものを
使用する。この撥水膜４としては多孔性のフッ素樹脂膜
を使用した。An air inflow hole 2 is provided at the bottom of a positive electrode case 1 having a flat bottom surface, and an air diffusion paper 3 is arranged at the bottom of the positive electrode case 1. The air diffusion paper 3 may be made of alkali-resistant material; alkaline cellulose is used in this embodiment, but it may be made of water-repellent material treated with fluororesin powder or the like. A water-repellent film 4 is disposed on the top of the air diffusion paper 3, and the outer diameter of the water-repellent film 4 is made larger than the outer diameter of the air diffusion paper 3 described above. As this water-repellent film 4, a porous fluororesin film was used.

この撥水膜４上に上述した各正極触媒層そ机ぞれ別に５
として配置し、更に正極触媒層５上に多孔性のアルカリ
セルロースよシなる七ノくレータ６を配置する。On this water-repellent film 4, each of the above-mentioned positive electrode catalyst layers is separately coated 5
Further, a seven-layer filter 6 made of porous alkali cellulose is placed on the positive electrode catalyst layer 5.

そして、亜鉛、ゲル化剤としてカルボキシメチルセルロ
ース、電解液として水酸化カリウム水溶液を負極体７と
し、この負極体７を内蔵した負極ケース８と前記した正
極ケース１とをポリプロピレン、ポリエチレン、ナイロ
ンなどの耐アルカリ性合成樹脂からなるガスフット９を
介し、正極ケース１の開口部を折曲することによシ封口
する。The negative electrode body 7 is made of zinc, carboxymethyl cellulose as a gelling agent, and potassium hydroxide aqueous solution as an electrolyte, and the negative electrode case 8 containing this negative electrode body 7 and the above-mentioned positive electrode case 1 are made of a durable material such as polypropylene, polyethylene, or nylon. The opening of the positive electrode case 1 is sealed by bending the gas foot 9 made of alkaline synthetic resin.

このようにして得られた正極触媒層５の違う空気電池を
実施例１．′実施例２．比較例の空気電池とした。The thus obtained air cells with different cathode catalyst layers 5 were used in Example 1. 'Example 2. This was used as an air battery as a comparative example.

この実施例１．実施例２．比較例の空気電池を使用して
短絡電流を測定した。This example 1. Example 2. Short circuit current was measured using an air battery as a comparative example.

以上の結果から判るように本発明の空気電池はシート状
の正極触媒層を使用した空気電池に比較して、大電流が
取シ出せるものである。尚。As can be seen from the above results, the air battery of the present invention can draw a larger current than an air battery using a sheet-shaped positive electrode catalyst layer. still.

実施例はボタン型空気電池で説明したが５本発明は、シ
ート状９円筒状、角柱状、カード状など各種形状の空気
電池としても使用できるものである。Although the embodiments have been described using button-type air batteries, the present invention can also be used as air batteries in various shapes such as sheet-shaped, cylindrical, prismatic, and card-shaped.

【図面の簡単な説明】[Brief explanation of the drawing]

図は１本発明の１形状を示すボタン型空気電池の縦断面
図である。 ５・・・・・・正極触媒層 特許出願人　べんてる株式会社The figure is a longitudinal sectional view of a button-type air cell showing one shape of the present invention. 5... Positive electrode catalyst layer patent applicant Bentel Co., Ltd.

Claims (1)

【特許請求の範囲】[Claims] 粉末状の活性炭と粉末状の導電性炭素とを正−極触媒層
に使用することを特徴とする空気電池。An air cell characterized in that powdered activated carbon and powdered conductive carbon are used in a positive electrode catalyst layer.