Translation guide
The cathode is the electrode where reduction occurs, or the negative terminal in a device. In Japanese, the term depends on context: electronics vs. electrochemistry.
The electrode from which electrons flow into a device, such as in a battery or vacuum tube.
The most common and general term for cathode in electronics, borrowed from English. Used in batteries, diodes, vacuum tubes, etc.
このダイオードのカソードは線が入っている方です。
The cathode of this diode is the side with the line.
The native Japanese term for cathode, literally 'negative pole'. Used in technical contexts, but カソード is more common in everyday electronics.
陰極線管は古いテレビに使われていました。
Cathode ray tubes were used in old televisions.
The electrode where reduction takes place, regardless of polarity.
Also used in electrochemistry for the electrode where reduction occurs. Context clarifies the meaning.
電気分解では、カソードで還元反応が起こります。
In electrolysis, reduction occurs at the cathode.
The formal term in electrochemistry as well. Often seen in textbooks and scientific papers.
カソード is the loanword and is widely used in both electronics and electrochemistry. 陰極 is the native term and sounds more formal or academic. In everyday conversation about batteries or diodes, カソード is preferred.
In a discharging battery, the cathode is the positive terminal, but in electrolysis, it's the negative terminal. The Japanese terms do not change; context determines the polarity.
陰極では金属イオンが還元されて析出します。
At the cathode, metal ions are reduced and deposited.