How to Make a High Voltage Battery

Last Updated: January 10, 2020

Everybody knows how you can make a battery from a lemon. You can also make batteries from cola or salt water. The problem is, these batteries have a low voltage. You can make a high-voltage battery using electrochemistry.

Part 1

Part 1 of 5:
Getting the Materials

1
Gather your materials. You will need: two glass beakers, filter paper and potassium nitrate for the salt bridge, aluminium foil and one molar aluminium nitrate solution for the negative electrode, wires and crocodile clips. The materials for the positive electrode vary. You will also need something to act as a circuit load, like a light bulb.
- One molar = one mole per litre.

Part 2

Part 2 of 5:
Preparing the Salt Bridge

1
Dissolve the potassium nitrate in water to form a solution.
2
Cut out a strip of filter paper.
3
Soak the filter paper with the solution.
4
Place the two beakers next to each other. Bend the filter paper so that it touches the bottom of both beakers.

Part 3

Part 3 of 5:
Preparing the Negative Half-Cell

1
Add the aluminium nitrate solution to one of the beakers.
2
Place a strip of aluminium foil into the solution. The strip should touch the bottom of the beaker. It should not touch the salt bridge. You may wish to bend the top of the strip over the edge of the beaker. This aluminium strip is the electrode.
- You have formed an Al3+/Al half cell.

Part 4

Part 4 of 5:
Preparing the Positive Half Cell

Using Cu2+/Cu

1
Gather your supplies. You will need: a strip of copper and some one molar copper nitrate solution.
2
Add the copper nitrate solution to the second beaker.
3
Place the copper strip in the second beaker. It should touch the bottom, but not the salt bridge. This is the positive electrode.
- This cell has a voltage of 1.821V.

Using Fe3+/Fe2+

1
Gather your supplies. You will need: one molar iron (III) nitrate (Fe(NO3)3) solution, one molar iron (II) nitrate (Fe(NO3)2) solution, and a conductive graphite rod.
2
Add equal amounts of each of the iron nitrates to the second beaker.
3
Place the graphite rod into the beaker. It should not touch the salt bridge. This is the positive electrode.
- This cell has a voltage of 2.432V.

Using Cr2O7 2- + 14H+/Cr3+

1
Get the supplies for this part. You will need: one molar potassium dichromate solution, one molar nitric acid, one molar chromium nitrate solution, and a conductive graphite rod.
2
To the second beaker, add: one measure of potassium dichromate solution, two measures of chromium nitrate solution, and an excess (>14 measures) of nitric acid. One measure should be the largest amount that you can add without the beaker overflowing after everything is added.
3
Add the graphite rod. It should not touch the salt bridge. This is the positive electrode.
- This cell has a voltage of 2.992V.

Using MnO4- + 8H+/Mn2+

1
Gather the correct supplies. You will need: one molar potassium permanganate solution, one molar nitric acid, one molar manganese nitrate solution, and a conductive graphite rod.
2
To the second beaker, add: one measure of potassium permanganate solution, one measure of manganese nitrate, and an excess (>8 measures) of nitric acid. One measure should be the largest amount that you can add without the beaker overflowing after everything is added.
3
Add the graphite rod. It should not touch the salt bridge. This is the positive electrode.
- This cell has a voltage of 3.172V.