Battery Basics: How Alessandro Volta's Invention Works

[wavingerwin]

Alessandro Volta uses a bimetallic strip (silver and tin) dipped in moist conductor (salty water) to make a battery.

how can a potential difference occur between the two strips?

in modern AA batteries, what do we use for the two dissimilar metals and the moist conductor?

 

[MATLABdude]

The potential difference doesn't arise per se; it's a measure of how easily one of the electrodes gives up electrons and transfers it to the other electrode:
http://www.chemguide.co.uk/physical/redoxeqia/introduction.html

A modern alkaline battery has electrodes made of zinc and manganese(IV) oxide (MnO2), with potassium hydroxide (KOH) as the electrolyte (and hence the reason it's called an alkaline--basic--battery).

WARNING: do NOT cut cells open without knowing what you're doing, or wearing appropriate safety equipment! The black paste you have when you cut a cell open is actually both the KOH solution and the suspended bits of MnO2 anode.

For more on a modern alkaline cell, see the Wikipedia article, or Duracell's handy-dandy information document:
http://en.wikipedia.org/wiki/Alkaline_battery
http://www.duracell.com/oem/Pdf/others/ATB-full.pdf

 

[wavingerwin]

hm i see.

it's a measure of how easily one of the electrodes gives up electrons and transfers it to the other electrode

so it's more to do with the atomics of the two electrodes.

WARNING: do NOT cut cells open without knowing what you're doing, or wearing appropriate safety equipment! The black paste you have when you cut a cell open is actually both the KOH solution and the suspended bits of MnO2 anode.

thanks for the warning. But i am more of a 'theoretical guy' if you like it. sigh..., i know i need to change this principle of mine soon. Maybe start with disassembling a remote control or a computer mouse...