Author Options:

Would this battery work? Answered

I want to make a compact battery, I need it to generate as many volts possible. The battery materials are the following:
Anode: Zinc
Cathode: Steel
Electrolyte: Sulfuric Acid

Is that the optimal anode and cathode I can use to get most volts out of it?


A quick look at Google will tell you a number of things.

If you REALLY want to manufacture a battery your going to be somewhat limited by the type of materials you can get at home.

MAX energy density will be lithium non rechargeable at about 1.8 Mjouls/kg

BUT you not going to work with lithium at home unless you have a considerable chemical laboratory.

You don't really give enough information to assess what your trying to do but

following existing technology is going to yeald the best results so look up Sealed Lead Acid battery and see where it takes you.

For inspiration watch this.

Well, what if it is rechargeable?

First of all, mixing alum/Epsom salts with Sulfuric Acid will make it rechargeable somehow?

The video shows a super capacitor, yes they are rechargeable. Watch the video and the others where he builds it.

A lead acid battery contains dilute sulfuric acid that's all, it is rechargeable - we are talking more or less a car battery here.

Mixing Alum and or Epsom salt will do nothing for the battery at all.

HOWEVER and take note of this - Your NOT going to get high voltages. A standard lead acid cell give you 2.3 volts. Hence a car battery has 6 cells to make up the 12 volts.

A lead acid battery is by its nature heavy and quite bulky and as Others have said the manufacture to get high efficiency is tricky and very technical.

We are not trying to put you off but there are some things that are technically very hard to do at home. You have picked one of them.

If you want to get the most out of it buy a proper battery.
Just a quick Google search would have showed that Steel is useless for your task as the acid will dissolve it - plus it will contaminate the "battery" reducing the available power.

The reason why I don't buy a proper battery is because I need as much voltage I can get out of a specifically shaped battery, which means I have to make it myself. Which anode and cathode materials would you suggest?

Lead plates in sulfuric acid - works a treat for ages, some even use it in cars I heard.
If size is an issue you roll the plates up using an acid safe seperator that won't collect gas.

That was exactly what I was thinking to do, roll them up and stick them in the battery, but which material is the anode and which one is the cathode?

Hmm is it really that hard to ask Google or Wikipedia? ;)
Your main problem will be to get lead sheets of good quality, meaning really even thickness, the normal roofing stuff is quite thick and might be overkill for the purpose.
Then, for making a rolled battery you need an insulating layer between the two lead sheets - which can support the stress of being rolled up.
Of course you can also make two seperate rolls with enough spacing to put a good seperator between them.
Back in the days people made their own D-Cells with caustic soda and other dangerous chemicals and as already pointed out with more hassle than power.
Let's just say you somehow manage to get a rolle up battery that is within your size limits - how do you determine how much power it has?
Sure each pair of plates will generate 2V - but how much in amp under load?
You have to get an even sulphate layer on one set of plates or spent ages forming it through charge and discharge - until then the battery will have little to no stamina.

Considering the available option for recharganle batterie I highly doubt you can not fins something suitable that is already produced.
And in the long run it might come much cheaper too....

If I added Alum/Epson Salt to the H2SO4 would it make the battery fully rechargeable?


2 years ago

Outside of proof-of-concept, it is completly impractical to build your own battery. Several youtubers have channels where they show some development in different homemade batteries. However, you will notice the things they power are generally very low power, and that a standard commercial battery is lightyears ahead in performance and stamina.

Creating a custom shaped custom battery pack is not a bad idea, and that not only would be a much better solution, you could achieve very good performance characteristics! Lithium ion batteries come in a HUGE variety of shapes and sizes, from standard 14500 (AA size), 18650 ("AA battery on crack" size) As well as small flat bricks (similar to phone batteries) and batteries literally the size of bricks, such as the LiPos used for RC models.

You can EVEN get lithium batteries which are film-shaped, and flexible! or coin cell lithium rechargeables! Those can be stacked to get some insane voltages, however, that is a bad idea. Connecting up more than like 6 lithium batteries would be a not so great idea as charging batteries connected in series is challenging. Most RC LiPo chargers support up to 4-6 series cells.

You can use an electrode potential table to determine cell voltage. As was mentioned, you will get the best results with commercial batteries. If you need more voltage place multiple batteries in series or use a boost converter.