March 2023
Intermediate
240 pages
7h 3m
Japanese
Content preview from 図解まるわかり 電池のしくみ
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
96
イタイイタイ病、酸素ガス
電池にカドミウムが使われ
続けていたのはなぜか？
3-8
ガスの発生をおさえるカドミウム
ニカド電池には、1960 年代にイタイイタイ病という公害問題を引き起
こした、人体に有害なカドミウムが含まれています（図3-15）。それでも
カドミウムがニカド電池に使われてきたのには、理由があります。
ユングナーが発明した当初のニカド電池では、鉛蓄電池と同様に、充電
末期から過充電になると電解質中の水が分解されて、負極から水素ガス、
正極から酸素ガスが発生するという問題がありました（3-6）。
しかしカドミウムは、一次電池の乾電池にかつて含まれていた水銀と同
じく、水素過電圧が高く（2-5）、酸素と反応しやすいという性質があり
ます。そこで負極活物質に使うカドミウムの量を十分取っておくことで、
負極の水素ガスの発生をおさえ、正極からの酸素ガスを負極で吸収させる
ことができるのです。このように電池内部でガスの生成をおさえることが
できるので、液漏れ問題の少ない密閉型の形成が可能となりました。
使い勝手のよい電池構造
現在のニカド電池は、一部のリチウム一次電池と同じく、電解質を含ん
だセパレータをはさんで正極板と負極板をロール状または積層にしたスパ
イラル構造（2-12）になっています（図 3-16）。これらは鉄缶に詰めら
れて、さらに外側は外装ラベルや絶縁チューブで覆われた密閉型です。ま
た正極端子からの酸素ガスが発生した場合に備えて、ガスを逃がすための
排出弁が取り付けられています。
このような構造により、ニカド電池は、丈夫で振動や衝撃に強く、大き ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Read now
Unlock full access
More than 5,000 organizations count on O’Reilly
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.