Galvanic cell

Things you should know about Galvanic Cell.

Think about the wall clock, torchlight, speakers, smartphones and other electronic gadgets.
We cannot imagine a single day without these electronic devices. One common thing in these
gadgets is the battery, the powerhouse of the device. It provides all the necessary energy. Have
you ever wondered how the battery work? To know about these new-age batteries, we first learn something about their forefather Galvanic cell.

Galvanic cells are electrochemical cell meaning it produces electrical energy from chemical reactions. In 1780, Luigi Galvani came up with an electrochemical cell idea. Later on, Alessandro Volta created a pile of electrochemical cells. These cells are named after Galvani, and meantime it’s also known as the Voltaic cell.


Principles of Galvanic Cell:

The galvanic cell produces electricity from spontaneous oxidation-reduction. Oxidation and
reduction are chemical reactions that involve electrons. When electrons are added to the main
chemical species is known as reduction. Electrons are released from the main chemical species
known as oxidation. These two chemical reactions start in an electrochemical cell without any
external input.

Checkout creating a wood ash battery on your own click here.

Galvanic cell principles
Galvanic cell

Parts of Galvanic cell:

  • Anode
  • Cathode
  • Electrolyte
  • Half cell
  • Porous material
  • External circuit

An anode is an electrode made up of metals. At the start of the reaction, the anode release
electrons and become an ion.

A cathode is also an electrode. Which receives an electron from the anode.

It’s a chemical solution that relates to the types of electrodes.

Half cell:
The half-cell is the separate unit that contains the electrode and its corresponding

Porous material:
The Bridgeway between both half cells. Ions move from one-half cell to another half-cell.
Sponge-like alignment only allows particular materials.

External circuit:
Electrochemical cells seamlessly produce electrical energy. We need an external circuit to
use the power. Without the customer, there’s no use in creating products.

Working of Galvanic cell:

In a Galvanic cell, when the electrode interacts with the electrolyte, that metal electrode
generates ions. Based on the electrode, it produces or absorbs the electron. But all types of
electrodes release the ions.

Working Principle of Galvanic cell

In an anode, the electron is released and moves to the external circuit. Cathode receives
electrons from the external circuit and becomes ions.
Both electrodes produce metallic ions, which interact with the electrolyte and move between
half cells with the help of porous material.

Porous material varies from cell to cell. The bridge allows the particular materials to move
between the half-cells of the Galvanic cell. Sometimes the bridge connects two half cells
externally or sometimes internally.

This chemical reaction cycle is repeated millions of times in the electrochemical cell and
produces electrical energy to the external circuit. Electrical power depends on the electrode.

Example of Galvanic Cell:

Here Zinc (Zn) and Copper (Cu) are taken as electrodes. Their respective electrolyte is zinc
sulfate (ZnSO4) and copper sulfate (CuSO4). The zinc electrode releases electrons to the
external circuit and Zinc ions (Zn2+) to the electrolyte solution.

These electrons move to another electrode and react with the copper electrode (Cu), where
the electrode reacts with electron and become copper (Cu2+) ions. These ions interact with each
electrode with a porous material.

?? → ??2+ + 2?−
??2+ + 2?− → ??

From this circuit, the cell produces a potential difference or electrochemical energy. This
varies between electrodes. Usually, the Galvanic cell gives 0.76 V. So, we need 3 Galvanic
cells to light up the red LED because it requires 2 V.
Galvanic Cell working

DIY Galvanic Cell:

Let’s make a simple Galvanic cell at a low cost. To provide enough power to operate a wall

Things we need:

  • Aluminium piece
  • Copper piece
  • wires
  • beaker or bottle
  • water
  • Wood ash

Take an aluminium piece and a copper piece from useless materials. Connect them with the
wires and make it is an open circuit. The taken metal pieces act as an electrode. Fill the beaker
or bottle with the Wood ash and some water to wet the wood ash.

The ash holds the water and increases the working time. Here aluminium acts as an anode,
and copper acts as a cathode. Both electrodes produce a voltage of 1.3 V, which is enough to
power the wall clock.

So, connect the positive terminal of the clock to the copper electrode and join the negative
terminal to the aluminium electrode.Keeping the wet wooden ash increase the stability of the electrochemical cell.

Galvanic cells are the ancestors of all batteries. In history, these cells go through lots of
updates to become the ones we are using today.


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