Lead Storage Battery
Definition and meaning of Lead Storage Battery in chemistry.
A lead storage battery is a rechargeable device that uses lead and sulfuric acid to make electricity. It is the oldest and most common type of rechargeable battery in the entire world. People primarily use these powerful batteries to start the heavy engines in their cars.
In more detail
This battery contains a series of internal cells that work together to produce power. Each individual cell contains two different types of metal plates sitting in a liquid. The negative anode plate is made from a spongy form of solid pure lead.
The positive cathode plate is coated in a dark brown chemical called lead dioxide. Both plates sit entirely submerged in a strong liquid bath of sulfuric acid. When you turn your car key, the battery releases a massive surge of electrons.
The lead on both plates reacts with the acid to form solid lead(II) sulfate. This chemical reaction also creates water that dilutes the strong acid pool. When your car engine is running, it pushes electricity back into the battery.
This fresh electrical current forces the chemical reaction to run in complete reverse. The solid lead sulfate turns back into pure lead and solid lead dioxide. The water also converts back into strong sulfuric acid for the next engine start.
Students often think the battery somehow creates power out of thin air. In reality, it simply stores chemical energy and releases it as electrical energy later. These batteries are very heavy but remain popular because they are cheap and reliable.
Key facts
| Field | Analytical Chemistry |
|---|---|
| Anode material | Spongy solid lead (Pb) |
| Cathode material | Lead dioxide (PbO2) |
| Electrolyte | Sulfuric acid (H2SO4) |
| Discharge product | Solid lead(II) sulfate (PbSO4) |
| Common use | Automotive car engines |
A standard car battery contains exactly six separate lead storage cells connected together in a row. Each individual chemical cell generates exactly two volts of raw electrical power. The combined six cells provide the twelve volts needed to start a typical car engine. When the weather gets very cold, this entire chemical process slows down significantly. This is why car batteries often struggle to start engines on freezing winter mornings.
Frequently asked questions
Why do lead storage batteries struggle in cold winter weather?
Cold temperatures naturally slow down all the chemical reactions inside the battery box. The slower reactions cannot produce enough electrical current to start a cold heavy engine.
What happens to the acid when the battery loses its charge?
The chemical reaction produces extra water as the battery releases its stored power. This newly formed water dilutes the strong acid and makes it much weaker over time.
How does a car battery recharge itself while you are driving?
The running car engine spins a special mechanical part called an alternator. The alternator pushes electricity back into the battery to reverse the chemical discharge reaction.