Batteries

Zinc-carbon battery

-Also known as a *standard carbon battery* -Zinc-carbon chemistry is used in all inexpensive AA, C and D dry-cell batteries -The electrodes are zinc and carbon, with an acidic paste between them that serves as the electrolyte

The obvious problem with wet cell batteries...

-Is the *need to be keep them upright or the electrolyte*, sulfuric acid, *will leak out* -However, the power they produce is quite substantial

Lithium Ion Batteries

-Not to be confused with Lithium single use batteries (like energizer e²) -These batteries are rechargeable

PbSO₄ will readily form Pb and PbO₂ if electric current is added back to the cell

-This happened completely by chance since there was no practical way to recharge the battery when it was invented -Later, the generator would be invented and from that a car's alternator, which easily recharges the battery while you drive

The electrolyte in batteries

-This is the *salt bridge* discussed earlier -It *allows ions to flow freely* while the *electrons travel across our load*, which is the thing you are trying to power

Over time, a lithium ion battery...

-Will not be able to hold as much of a charge, so it will need to be recharged more often -It will take less time to recharge when this occurs

Two major types of batteries

1. Wet Cell Batteries 2. Dry Cell Batteries

When was the standard battery used in a car invented?

1859 by Gaston Planté

How many cells are linked together in car batteries?

6 cells

What lithium ion batteries use

A lithium compound as the cathode and variety of possibilities for the anode material

Dry cell battery examples

AA, AAA, C, D, 9V etc.

The electrolyte normally needs to be...

Acidic or basic to make the redox reaction occur

Recycling car batteries

Almost all are recycled (~98%)

A 9 V battery is a battery

Because it has 6 cells linked together in the rectangular case

The name battery was coined by

Benjamin Franklin

Wet cell battery examples

Car batteries or batteries with a liquid inside

All batteries contain

Caustic chemicals that are potentially hazardous to the environment

What are lithium ion batteries commonly used in?

Cell phones, laptops and other portable electronic devices

Battery

Combination on 2 or more electrochemical cells that convert chemical energy into electrical energy

Volta connected...

Galvanic cells together in a series

Why not use HCl for the electrolyte?

HCl would be a very poor choice because of the redox reaction 2 HCl → H₂ + Cl₂ Hydrogen typically gets reduced 2 H+ +2e⁻ → H₂ But chlorine getting oxidized is very dangerous because of the *poisonous gas produced* 2 Cl⁻ → 2e⁻ + Cl₂

Sulfuric acid

Is commonly used in batteries; it is commonly called *battery acid*

The nice thing about lead-acid batteries...

Is that they're easily rechargeable

Lead-Acid Battery (standard battery in a car)

It uses a Lead plate and a Lead Dioxide plate in a sulfuric acid solution

Lithium-iodide battery

Lithium-iodide chemistry is used in pacemakers and hearing aids because of their long life

Who is credited with the invention of the first batteries?

Luigi Galvini and Allesandro Volta

The unbalanced redox reaction of a lead-acid battery

Pb + PbO₂ + H₂SO₄ ⇌ PbSO₄ Reduction half PbO₂ + H₂SO₄ ⇌ PbSO₄ Oxidation half Pb + H₂SO₄ ⇌ PbSO₄

No battery should be...

Put into landfills, as they will eventually break down and leak chemicals over time that poison the surrounding area

All batteries break down over time

Rechargeable batteries normally produce some other compound through an irreversible reaction

Why did Franklin call them batteries?

The batteries at the time were a series of connected jars, which reminded him of a battery of cannons

Nickel-cadmium battery (NiCd)

The electrodes are nickel-hydroxide and cadmium, with potassium-hydroxide as the electrolyte (rechargeable)

Galvini came up with

The galvanic cell

Normal AA AAA C and D batteries are alkaline

These are dry cell batteries

A single AA, AAA, C or D "battery" is not a battery by definition

They are all single cells

Lithium ion batteries are very light for the power they produce

They can be built to a variety of shapes to fit their device

If you try to recharge an alkaline battery...

They may leak

Zinc-air battery

This battery is lightweight and rechargeable

Nickel-metal hydride battery (NiMh)

This battery is rapidly replacing nickel-cadmium because it does not suffer from the memory effect that nickel-cadmiums do (rechargeable)

Zinc-mercury oxide battery

This is often used in hearing-aids

Silver-zinc battery

This is used in aeronautical applications because the power-to-weight ratio is good

Wet Cell Batteries

Use a liquid electrolyte to allow the ions to freely exchange during the redox reaction

Dry Cell Batteries

Use a paste that immobilizes the electrolyte

A "battery" is not a battery until...

You connect them together, like you have to in most devices

Reaction of alkaline batteries

Zn + MnO₂ → ZnO + Mn₂O₃ -This occurs in a paste of KOH -This reaction is not reversible!