Batteries are made of two metals with different electron affinities. What does the phrase “electron affinity” mean and how does this affinity affect the voltage of the battery?

Question

isaiah.feynman · Answer

Electron affinity is affinity an INDIVIDUAL atom feels for an electron.

anonymous · Answer

How does the affinity affect the voltage then?

masumanwar · Answer

It is the change in energy to form a negative ion and it effect voltage for principle quantum number

anonymous · Answer

So a higher affinity means a higher voltage and vice versa right?

masumanwar · Answer

Depending on the anode and cathode potential difference

anonymous · Answer

Ok so lets say i have a 12 volt car battery. The affinity of the metals inside will affect the output of voltage right?

masumanwar · Answer

Yup

anonymous · Answer

Alright thank you!

theeric · Answer

Here's what I understand, but I'm not positive about it (no pun intended). I would appreciate anyone correcting me, or shedding more light on this, or debating it.

At the anode, there is a reaction with the electrolyte that releases an electron or more.
At the cathode, there is a reaction with the electrolyte that takes a free electron.

Electron affinity comes in here.
When the electron becomes part of an atom, it loses some of the energy associated with it.
When the electron is released from an atom, because the energy exited the electron out of the atom, the electron has the added energy. The electron or electrons released now have an energy associated with them.

That is the voltage, by definition, where voltage is energy per charge. Common units are joules per coulomb.