Lets Set The Stage
For centuries now, ever since the first gasoline powered
vehicles were invented there has been a drive to find a
cleaner energy source.
Ever since the electric powered car was invented in 1888,
it has drifted in and out of popularity for various reasons.
Mostly because of limitations like:
Battery Life
Power (Top speed)
Power (Step on the pedal and go)
These problems
have all been
solved btw….
Gasoline Vs Electric Cars
Gasoline engines are about 20% efficient…..so that
means that 80% of the energy in the gas you buy is
lost and pollutes the environment.
By comparison electric cars are around 90%
efficient.
Gasoline powered engines require regular
maintenance to stop problems resulting from the
incomplete burning of gasoline.
Electric engines require very minimal maintenance
to replace things that would need replacing no
matter what type of car you have.
Gasoline Vs Electric Cars
The extraction of fossil fuels causes huge amounts of
pollution.
In fact, the CO2 pollution created by the extraction of
fossil fuels in Alberta is equal to the amount of CO2
produced in the rest of Canada.
The electricity that electric cars use is often produced by
burning fossil fuels anyway.
But you’d have a hard time finding anything in your
house that is 90% efficient.
Did I mention that electric engines are almost silent?
Gasoline Vs Electric Cars
Lets Put This In Perspective
So you go and fuel up your ride….its a 60 L Tank.
Lets say gas is $1.20/L…it’s a pretty good average.
So it costs you ($1.20/L)(50L)= $60.00
So gasoline engines are 20% efficient…
That means that out of the $60.00 to gas up you
car/truck you only actually use $12.00 of it.
$12.00!
$48.00 just floated off as pollution.
Pollution that you will eventually pay(again) to get rid of.
So Why Aren’t We Using Electric
Cars?
Well because their less efficient.
85% vs 20%...right….
Because their ugly.
How a car looks has little to nothing to do with the engine.
Because they aren’t ready yet, too many problems, the
technology doesn’t exist yet
The first electric car was invented in 1888!
Their too slow, we have places to be.
Electric Car vs Porsche 911 Turbo
Electric Cars Are Better
The batteries to run the car are too heavy and not
powerful enough.
The Battery
The Electric Car’s “Ball and Chain”
The biggest obstacle stopping the wide spread use of
electric cars is the lack of a powerful, lightweight, and
inexpensive battery to power it.
The old Lead-Acid battery (The big klunker you put in
your car…youv probably all seen them) is:
 Too Heavy
 Too Weak
 Doesn’t last long enough
 Expensive
The Battery “Problem”
Designing A Battery For The Future
Designing a new battery that is lightweight, inexpensive,
powerful, and long lasting would make electric powered
vehicles far, far, far, farrrrrrr superior to gasoline
powered vehicles.
So how do we do?
How does a battery work?
If were going to make a new battery we kind of have to
know how one works in the first place.
***A battery stores/creates electricity through a
redox reaction.***
The Lead-Acid Battery
Lets Make The Redox Equation
Sulfuric Acid and Lead Battery.
Hint: Lead and Lead Oxide
H2SO4(aq) + Pb(s) + PbO2(s)
H+(aq) + SO42-(aq)
+ H2O(l)
The Lead-Acid Battery
Lets Make The Redox Equation
Sulfuric Acid and Lead Battery.
SOA
OA
OA
H+(aq)+ SO42-(aq) + Pb(s) + PbO2(s) + H2O(l)
RA
SRA
RA
The Lead-Acid Battery
Lets Make The Redox Equation
PbO2(s) + SO42-(aq) + 4H+(aq) +2e-  PbSO4(s) + 2H2O(l)
SOA
OA
H+(aq)+ SO42-(aq) + Pb(s) + PbO2(s) + H2O(l)
RA
SRA
Pb(s) + SO42-(aq)  PbSO4(s) +2e-
Recharging
Taking Reactants and Creating
Redox Equations
To this point you have learned how to do all the steps of
taking chemical reactants and creating an oxidation ½
and a reduction ½.
Even more than that, you can add the two together and
get an overall equation.
What this unit is about, is taking that knowledge of
redox reactions and using the Electrical Potential
E° (V) values from your data booklet.
Allesandro Volta invented the first electric cell.
Allesandro was inspired by another scientist that noticed
that when he electrocuted a frog’s leg it twitched.
Who said electrocuting random stuff doesn’t help
you learn.
You know what this means right!!?
+
=
Google Images of “Learning”
Volta’s
“Electric Cell”
Anode
(-)
Electrons
Metal
rods
flow
from the
are
referred
Negative
to
as the pole
(Anode) to
“electrodes”
the
positive
or
“poles”
pole
(+)
and (-).
(Cathode).
(+) Cathode
Positive(+) pole is called the
cathode.
Negative(-) pole is called the
anode.
The “flow” of electrons
is called Electricity.
Electrolyte solution
(Salt Water/NaCl)
Volta’s
“Electric Cell”
Electricity created from the flow of electrons from one pole
to the other was so small that it wasn’t enough to be useful.
Solution?
Volta’s
“Electric Cell”
An electric cell does not conduct electricity unless the poles are
connected together.
The Car Battery
The Battery broken in 6 cells
connected together in a chain.
Volt
The size of
the battery
doesn’t
necessarily
mean its
voltage is
higher.
Bigger
batteries can
store more
energy and
transfer more
at one time.
Meter
The Volt Meter
measures the
electric
potential
difference
between the
cathode and
the anode.
Ammeter
An ammeter measures the “flow” of electrons.
Bigger batteries can have the same voltage as smaller
batteries, but because their bigger they can send a
higher volume of that potential energy at one time.
Larger volume per time means that the rate of flow from
a big battery is higher.
Amperage (ammeter unit) is a measure of the rate of
electron flow.
1 Amp = 1 Coloumb/second
Voltage, Coulombs, Amperage
Voltage
Voltage is the electric potential difference between the two
poles.
Measures the difference between how many electrons are
at the anode and how many are at the cathode.
Voltage is specific to the type of battery, IT IS NOT
AFFECT BY THE SIZE OF THE BATTERY!
You can get a 1.5 Volt battery in any size; AAA, AA, C, D
…whatever, size doesn’t matter.
Voltage, Coulombs, Amperage
Coulombs
Coulomb is a measure of the amount of energy stored in a
battery.
Coulombs are expressed as Q…..a measurement of energy
only.
How many coulombs of energy is dependant on the size of
the battery.
LIKE THE VOLUME OF A BATTERY.
2 Coulombs
800 Coulombs
Voltage, Coulombs, Amperage
Amperage
Amperage is the rate/speed at which electricity can flow
out of the battery.
Amperage is the amount of electrons/second.
Amperage is Coulombs/second.
0.55 amps or 0.55 C/s.
4 amps or 4 C/s.
Voltage, Coulombs, Amperage
The “Water Tank/Hose” Analogy
Voltage is determine
by the type of
reaction.
Since both tanks hold
water so the voltage is
the same for both.
115L Liter Hat Water Tank
Amperage is 11350 Liter Water Tank
the rate.
Coulombs are
a measure
Which
would have of
a amount, volume
higher “rate”
flow?
in this case......115L
vsof11350L.
Batteries
The Zinc-Chloride
battery.
One of the most
common and
inexpensive
batteries.
Invented in 1865.
Batteries that are sealed and can’t leak are called
dry cells.
1.5V
1.5V
1.5V
1.5V
9V
1.5V
1.5V
The common 9V
D cell battery is
made up of 6
seperate cells.
2 Types of Cells
Primary Cells: A electric cell that cannot be
recharged, once the chemicals in the batter
react to produce electricity it can never be
reversed.
Carbon-Zinc
Zinc-Chloride
Mercury-Mercury Oxide
Secondary Cells: An electric cell that can be
recharged. The chemical reaction that occurs
to produce electricity can be reversed if
electricity is applied to the cell.
Nickel-Cadmium
Lithium-Ion
Lead-Acid
Recharging A Battery
Reverse Net Redox Equation
When you charge a secondary cell the net redox reaction
equation is the reverse reaction.
Lead-Acid Battery
PbO2(s) + SO42-(aq) + 4H+(aq) +2e-  PbSO4(s) + 2H2O(l)
+
Pb(s) + SO42-(aq)  PbSO4(s) +2ePbO2(s) + 2SO42-(aq) + 4H+(aq) + Pb(s)  2PbSO4(s) + 2H2O(l)
Discharging
Charging
Fuel Cells
40-70% Efficient
Operate in the exact same way as a primary electric cell.
You put “fuel” into the cell (the fuel can be anything that
will react to produce electricity) just like you put
reactants into a battery……which are used up (cant be
reversed) just like a primary electric cell.
Except!
In a fuel cell, its not sealed and you continuously put
“fuel” into it, adding more as it get consumed by the
reaction.
A fuel cell never runs out and dies like a battery.
As long as you keep adding fuel, it keeps going.
Hydrogen-Oxygen Fuel Cell
70% Efficient
Forward
H2
O2
O2
H2O
H2
(OH-)
H2
O2
H2O
Hydrogen-Oxygen Fuel Cell
NET REDOX EQUATION
4.
Balance electrons and add reactions
1.
List all the species present and label OA & RA.
together….remember to cancel out “doubles.”
/
Back
OA
SOA
H2(g) + OH(aq) /+ H2O(l)/+ O2(g)
2
SRA
RA
+
2
H
4
OH
→
4
H
O
+
4
e
/ write
/ .
(aq) its oxidation
/ 2 (l)equation
2. Choose2(g)SOA and
- → 4 OH
O
2
H
O
+
4
e
2 H2(g)2(g)
+ O2(g) 2+ 4(l)OH(aq) → 2 H2O
(aq)
(l)
3. Choose SRA and write its reduction equation.
H2(g) 2 OH(aq) → 2 H2O(l) + 2 e-
X2
Couple Other Options
Aluminum-Oxygen Cell
• _ Possible use in
electric cars.
• _ Replaceable solid
aluminum fuel.
• _ High energy density.
• _ 3 moles of electrons
released for each Al.
• _ Aluminum is light
weight.
• _ Replace aluminum
every 2500km.
Industrial Fuel Cells
• _ Same as small scale but no
volume weight concern.
• _ Need longer lifetime of
fuel in cells.
• _ Almost always cogeneration units.
• _ Produce electricity AND
heat.
• _ 90% efficient!
• _ Produce 400 Mega Watts!