It comes from the fact that in an electrochemical cell, the cations are those that are reduced.

这来源于在电池中，正离子是被减少的。

麻省理工公开课 - 固态化学导论课程节选

So, for example, in an electrochemical cell, it would be possible to take the sodium ion, give back its electron, and convert it into a metallic sodium, take the chloride ion, remove its electron, and restore chlorine gas.

所以，例如一个电化学的电池，它可能带有钠离子，让它得到电子，把它变成金属钠，得到氯离子，让它失去电子，作为氯气储存。

麻省理工公开课 - 固态化学导论课程节选