JPS61271747A - Silver oxide cell - Google Patents

Abstract

PURPOSE:To enable high-efficiency discharge characteristics with less silver, by providing a positive electrode whose main active material is made of granular silver oxide and which includes flaked silver powder of specified thickness and particle size mixed in. CONSTITUTION:A silver oxide cell utilizes a positive electrode which is made by compression-forming a granular silver oxide of particle sizes 50-350mum to which flaked silver powder of thickness 0.05-0.5mum and particle size 0.1-15mum is mixed in. The positive electrode thus made can maintain electric conductivity between highly resistive silver oxide particles and satisfy the highly efficient discharge with mixing of less amount of flaked silver powder, in comparison with the conventional method which mixes spherical silver powder into silver oxide powder. This is because the flaked silver powder has larger surface area and can fill the space between the silver oxide particles more effectively to maintain conductivity than spherical silver powder. The granulated silver oxide powder reduces the surface area of silver oxide, enabling to maintain electric conductivity with far less quantity of the flaked silver powder.

Description

【発明の詳細な説明】 産業上の利用分野 本発明は、酸化銀を主剤とした正極を用いる酸化銀電池
に関するものである。DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a silver oxide battery using a positive electrode mainly composed of silver oxide.

従来の技術 従来、酸化銀を主剤とする正極活物質を用いたボタン形
酸化銀電池は、負極に亜鉛を用いた電池が商品化されて
いる。この電池の正極は粒子径が７μ論程度の酸化銀粉
末に５重量％の黒鉛粉末を混合して圧縮成形したものが
用いられている。近年、このボタン形酸化銀電池は、こ
れを電源とする使用機器、例えば電子腕時計、電卓等の
小形。BACKGROUND OF THE INVENTION Conventionally, button-shaped silver oxide batteries using a positive electrode active material containing silver oxide as a main ingredient have been commercialized, and batteries using zinc as a negative electrode have been commercialized. The positive electrode of this battery is made by compression molding a mixture of silver oxide powder with a particle size of about 7 μm and 5% by weight of graphite powder. In recent years, this button-shaped silver oxide battery has been used in small devices such as electronic watches and calculators that use it as a power source.

薄形化に伴い高電気容量化が要望されている。As devices become thinner, higher capacitance is desired.

この高電気容量化として正極体の電導助剤である黒鉛に
比べて嵩密度の高い銀粉末を用いることが提案されてい
る。この方法は、粒子径が約７μｌの酸化銀粉末に一般
的に知られている・球状の銀粉末を混合し、圧縮成形し
たものである。この方法を採れば、黒鉛を混合した正極
体に比べ、約１．１倍の高電気容量化が図れる。In order to increase the electric capacity, it has been proposed to use silver powder, which has a higher bulk density than graphite, which is a conductive additive in the positive electrode body. In this method, commonly known spherical silver powder is mixed with silver oxide powder having a particle size of approximately 7 μl, and the mixture is compression molded. If this method is adopted, the electric capacity can be increased by about 1.1 times compared to a positive electrode body containing graphite.

発明が解決しようとする問題点 しかし、銀粉末を混合する場合、正極の活物質である酸
化銀粉末間の電導性を保持させ、かつ高率放電特性を満
足するには、酸化銀粉末に７〜８重量−の銀粉末を加え
る必要がある。したがって、高価格な銀粉末を多量に使
用することから、電池のコストが低価格の黒鉛を使用す
る方法に比べ高くなるという問題点がある。Problems to be Solved by the Invention However, when mixing silver powder, in order to maintain conductivity between the silver oxide powder, which is the active material of the positive electrode, and to satisfy high rate discharge characteristics, it is necessary to add 7% to the silver oxide powder. It is necessary to add ~8 wt. of silver powder. Therefore, since a large amount of expensive silver powder is used, there is a problem that the cost of the battery is higher than that of a method using inexpensive graphite.

本発明は、このような問題点を解決することを目的とし
たものである。The present invention aims to solve these problems.

問題点を解決するための手段 本発明は、粒子径５０〜３５０μｍの顆粒状酸化銀に、
厚みが０・０５〜０・６μｍ１粒子径が０．１〜１５μ
ｍのフレーク状銀粉末を混合し、圧縮成形して正極とし
たものである。Means for Solving the Problems The present invention provides granular silver oxide with a particle size of 50 to 350 μm,
Thickness: 0.05-0.6μm 1 Particle size: 0.1-15μ
A positive electrode was prepared by mixing flaky silver powder of m and compression molding.

作用 この構成を採れば、従来の酸化銀粉末に球状の銀粉末を
混合する方法に比べ、少量のフレーク状銀粉末の混合で
高抵抗な酸化銀粉末間の電導性が保持でき、高率放電を
満足することができる。これは、球状銀粉末に比べてフ
レーク状銀粉末は、その表面積が大きく、酸化銀粉末間
に薄く入り込んだ状態で電導性を保たせることができる
。更に酸化銀粉末を顆粒状にすることにより、酸化銀の
表面積が小さくなり、更に少ないフレーク状銀粉末によ
り電導性を保たせることができるからである。Function: Compared to the conventional method of mixing spherical silver powder with silver oxide powder, this configuration allows the conductivity between high-resistance silver oxide powders to be maintained by mixing a small amount of flaky silver powder, resulting in high rate discharge. can be satisfied. This is because the flaky silver powder has a larger surface area than the spherical silver powder, and can maintain conductivity even when thinly intercalated between the silver oxide powders. Furthermore, by making the silver oxide powder into granules, the surface area of the silver oxide becomes smaller, and electrical conductivity can be maintained with even less flaky silver powder.

実施例 以下、本発明の詳細な説明する。Example The present invention will be explained in detail below.

粒子径が１５０μ■の顆粒状酸化銀に、厚みが０．１μ
ｍ２粒子径が２μｍのフレーク状銀粉末を２重量％混合
した。この合剤をムとする。同様に上記フレーク状銀粉
末ｔ−３重量％混合した合剤をＢ、５重量％混合した合
剤をＣ１７重量％混合した合剤をＤとした。次に比較列
として平均粒子径が７μｍの酸化銀粉末に粒子径が２μ
ｍの球状銀粉末を２重量％混合した合剤をＸ、３重量％
混合したものをＦ、６重量％混合したものをＧ、７重量
％混合した合剤をＨとして用意した。上記ム〜Ｈの各合
剤を２１秤量し、２ｏｏｋｇ／ｄの圧力で圧縮した条件
で比抵抗を測定した。上記各合剤ム〜Ｈの比抵抗値を第
１図に示す。Granular silver oxide with a particle size of 150μ■ and a thickness of 0.1μ
2% by weight of flaky silver powder having an m2 particle size of 2 μm was mixed. This mixture is called Mu. Similarly, B was a mixture in which 3% by weight of the flaky silver powder was mixed, and D was a mixture in which 17% by weight of C was a mixture of 5% by weight. Next, as a comparison column, silver oxide powder with an average particle size of 7 μm has a particle size of 2 μm.
A mixture of 2% by weight of spherical silver powder of m is mixed with 3% by weight of X.
The mixture was prepared as F, the mixture of 6% by weight was designated as G, and the mixture of 7% by weight was designated as H. 21 pieces of each of the above mixtures M to H were weighed and the specific resistance was measured under the condition that they were compressed at a pressure of 2 ook kg/d. The specific resistance values of each of the above mixtures M to H are shown in FIG.

この結果から、従来の球状銀粉末を７重量％混合した合
剤Ｈの比抵抗と、本発明のフレーク状銀粉末を３重量％
混合した合剤Ｂの比抵抗値がほぼ同じであった。また、
フレーク状銀粉末を混合した合剤は、その混合量が３重
量−以上であれば比抵抗値がほぼ同じになることがわか
った。この比抵抗は、電池に組み立てた場合、著しく大
きいと高率放電時の維持電圧が低くなることが考えられ
る。From this result, the specific resistance of Mixture H, which is a mixture of 7% by weight of conventional spherical silver powder, and 3% by weight of flaky silver powder of the present invention.
The specific resistance values of the mixed mixture B were almost the same. Also,
It was found that the mixture containing flaky silver powder has almost the same specific resistance value if the mixed amount is 3 weight or more. If this specific resistance is significantly large when assembled into a battery, it is thought that the sustaining voltage during high rate discharge will become low.

そこで、次に上記合剤を用いて直径９．６ｆｆ、厚み２
ｆｆのボタン形電池を組み立てた。第２図にそ第　２表
　　　　　　単位：Ｖ この結果より従来の球状銀粉末を混合した電池ｅ−ｆで
は、７重量優混合した電池りでないと、腕時計のランプ
使用時、８ｍムの電流を流した時の点燈ができなくなる
。このランプに必要、な維持電圧は１．２０Ｖである。Therefore, next, using the above mixture, a diameter of 9.6 ff and a thickness of 2
I assembled a ff button battery. Figure 2 shows Table 2 Units: V These results show that when using a watch lamp, a battery e-f containing conventional spherical silver powder can carry a current of 8 mm when used as a watch lamp, unless the battery contains a mixture of 7% by weight. The light will not turn on when it is turned on. The required maintenance voltage for this lamp is 1.20V.

また、本発明によるフレーク状銀粉末を混合し、組み立
てた電池＆−（ｌでは３重量％を混合すればランプの点
燈が可能である。これは、前記試験結果の比抵抗値と関
連があり、約１ｏΩ・１以下の値でないと高率放電特性
が満足できないことがわかる。In addition, if the flaky silver powder according to the present invention is mixed with 3% by weight of assembled batteries, it is possible to light the lamp.This is related to the specific resistance value of the test result. It can be seen that the high rate discharge characteristics cannot be satisfied unless the value is about 1 oΩ·1 or less.

上記実施列では粒子径が１５０μ諺の顆粒状酸化銀を用
いたが、次に粒子径が１００μｍ、５０μｍ。In the above example, granular silver oxide with a particle size of 150 μm was used, and next, particles with a particle size of 100 μm and 50 μm were used.

２０μｍの顆粒状酸化銀と従来列で使用した７μｍの酸
化銀粉末を用いて、上記実施例と同じフレーク状銀粉末
を３重量優混合して上記と同一条件で比抵抗を測定した
。その結果、顆粒状酸化銀で粒子径１００μｍのものが
０．５Ω・１．５０μ重のものが２Ω・１．２０μｍが
２ｏΩ・１となり、酸化銀粉末を用いたものは３６Ω・
１　となった。このことから高率放電特性を満足するに
は１０Ω・１以下が必要であシ、顆粒状酸化銀の粒径が
５０μｍ以上のものが好ましいことがわかった。これは
・酸化銀の表面積が小さい程、酸化銀間の電導性を保持
するための銀量が少なくてよいと思われる。Using 20 μm granular silver oxide powder and 7 μm silver oxide powder used in the conventional column, 3 weights of the same flaky silver powder as in the above example were mixed and the specific resistance was measured under the same conditions as above. As a result, granular silver oxide with a particle size of 100 μm has a value of 0.5Ω, 1.50 μm has a weight of 2Ω, 1.20 μm has a value of 20Ω·1, and silver oxide powder with a particle size of 36Ω·
It became 1. From this, it was found that in order to satisfy high rate discharge characteristics, a resistance of 10 Ω·1 or less is required, and it is preferable that the particle size of the granular silver oxide be 50 μm or more. This seems to be because - the smaller the surface area of silver oxide, the smaller the amount of silver required to maintain conductivity between the silver oxides.

なお、顆粒状酸化銀の粒子径が３５０μｍ以上では、非
常に粒子が壊れ易く、秤量時の）くラツキが大きくなる
という問題点ができることから、粒子径５０〜３５０μ
ｍの顆粒状酸化銀にすることが好ましい。　　・ また、上記実験では厚み０．１μｍ９粒子径２μｍのフ
レーク状銀粉末を用いたが、０．０５μ論の厚み以下で
は粒子が壊れ易く製造が難しい。逆に０．５μｍ以上の
厚みであれば３重量％混合時に比抵抗が１０Ω・１以上
となり、電池組立体の高率放電特性が満足できなかった
。またフレーク状銀粉末の粒子径０．１μｍ以下で３重
量％混合時の比抵抗が１０Ω・α以上となシ、粒子径が
１５μｍ以上の場合も１ｏΩ・１以上となった。これは
、酸化銀粉末にフレーク状銀粉末を混合した場合、粒子
径が１５μ論以上のフレーク銀粉末では不均一な混合状
態になシ、また粒子径が０．１μｍ以下の場合は、二次
粒子を作シ易く均一混合ができないからである。In addition, if the particle size of granular silver oxide is 350 μm or more, the particles are very easy to break and there is a problem that the clutter during weighing becomes large.
It is preferable to form granular silver oxide of m. -Also, in the above experiment, flaky silver powder with a thickness of 0.1 μm and a particle size of 2 μm was used, but if the thickness is less than 0.05 μm, the particles are easily broken and manufacturing is difficult. On the other hand, if the thickness was 0.5 μm or more, the specific resistance would be 10 Ω·1 or more when mixed at 3% by weight, and the high rate discharge characteristics of the battery assembly could not be satisfied. Further, when the particle size of the flaky silver powder was 0.1 μm or less, the specific resistance when mixed at 3% by weight was 10Ω·α or more, and when the particle size was 15 μm or more, it was also 10Ω·1 or more. This means that when flaky silver powder is mixed with silver oxide powder, flake silver powder with a particle size of 15 μm or more will not be in a uniform mixed state, and if the particle size is 0.1 μm or less, secondary This is because particles are easily formed and uniform mixing cannot be achieved.

以上のことから、フレーク状銀粉末の厚みが０．０５〜
０．５μｍ１粒子径かへ１〜１５μｍであシ、粒子径が
５０〜３５０μｍの顆粒状酸化銀を用いることによシ銀
の使用量が従来の７重量−から３重量％に減少でき、少
ない添加量で高率放電特性を満足することができる。From the above, the thickness of flaky silver powder is 0.05~
By using granular silver oxide with a particle size of 50-350 μm, the amount of silver used can be reduced from the conventional 7% by weight to 3% by weight. High rate discharge characteristics can be satisfied depending on the amount added.

発明の効果 以上のように本発明によｎば、少ない銀量で高率放電特
性を満足することができ安価な酸化電池が提供できる。Effects of the Invention As described above, according to the present invention, an inexpensive oxidation battery that can satisfy high rate discharge characteristics with a small amount of silver can be provided.

また同一サイズであれば従来の約１．１倍の容量アップ
ができ、時計用電源として好適な酸化銀電池が得られる
。Furthermore, if the size is the same, the capacity can be increased by about 1.1 times compared to the conventional one, and a silver oxide battery suitable as a power source for watches can be obtained.

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

嬉１図は本発明の実施列における正極合剤の比抵抗値を
示す図、第２図は本発明の実施例における酸化銀電池の
断面図である。 １・・・・・・正極ペレット、２・・・・・・正極ケー
ス、３・・・・・・正極リング、４・・・・・・負極合
剤、６・・・・・・負極ケース、ｅ・・・・・・セパレ
ータ、７・・・・・・含浸材、８・・・・・・シール材
。 代理人の氏名　弁理士　中　尾　敏　男　ほか１名第１
図 ！ｌ及粉木テ昆合比率（１量２ジ ／　　−−一王極へ°レット ２−一一王極り−ス ８−−−シール材Figure 1 is a diagram showing the specific resistance value of the positive electrode mixture in an embodiment of the present invention, and Figure 2 is a cross-sectional view of a silver oxide battery in an example of the present invention. 1...Positive electrode pellet, 2...Positive electrode case, 3...Positive electrode ring, 4...Negative electrode mixture, 6...Negative electrode case , e... separator, 7... impregnating material, 8... sealing material. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
figure! l and powder wood and combination ratio (1 quantity 2 di/--to one king pole 2-1 one king pole-su 8---sealing material

Claims (1)

【特許請求の範囲】[Claims] 主活物質が粒子径５０〜３５０μｍの顆粒状酸化銀から
なり、上記顆粒状酸化銀に厚みが０．０５〜０．５μｍ
、粒子径が０．１〜１５μｍのフレーク状銀粉末を混合
した正極を有する酸化銀電池。The main active material consists of granular silver oxide with a particle size of 50 to 350 μm, and the granular silver oxide has a thickness of 0.05 to 0.5 μm.
, a silver oxide battery having a positive electrode mixed with flaky silver powder having a particle size of 0.1 to 15 μm.