Studied by 13 people
Looks like no one added any tags here yet for you.
Battery
device used to convert chemical energy into electrical energy
Cell
single unit that is used to convert chemical energy into electrical energy
Current capacity
amount of current a power source is capable of supplying
Electromotive series of metals
list of metals that can be employed to construct Voltaic cells
Hydrometer
device used to measure the specific gravid of a fluid
Hydrometers are used for testing what devices
lead-acid batteries
Internal resistance
resistance inherit to a power source
Load test
test for determining the conduction of charge
Nickel-Cadmium cell aka
Nicad
Nicad cell
voltaic cell using Nickel and cadmium as cell plates with potassium hydroxide as electrolyte producing 1.2v per cell
Piezoelectricity
production of electricity by applying pressure to a crystal
Primary cell
a cell that cannot be recharged
Secondary cell
a cell that can be recharged
Voltaic cell
device that converts chemical energy to electrical energy
Voltaic pile
group of voltaic cells connected together to form a battery
A battery is several ___ connected together
cells
Volta’s cell was made of
Zinc and silver disks separated by cardboard soaked in brine
Who created the first practical battery
Alessandro Volta
individual cell voltage determined by
material it is constructed of
What list ranks how easily metals give up electrons
the electromotive series
How are metals chosen for batteries
how easily they give up electrons
Factors that determine current capacity
type of cell
rate of current flow
voltage
length of time
2 Common rating for cells
milliampere-hour (mA-hr)
Watt-hour (W-hr)
What are primary cells limited by
size and weight
Electrode
terminals that conduct electricity into or away from a conducting substance
One of the first primary cells
Zinc-Copper
Zinc Copper cell electrodes
Zn
Cu
Zn-Cu electrolyte
HCl
Zn-Cu voltage
1.08V
What is formed in Zn-Cu cells as a result of electrolyte ions reacting with electrode ions
Hydrogen gas
What happens to the Zn electrode over time in a Zn-Cu cell
it erodes as Zn ions continually leave the electrode
Who invented the first practical primary cell
LeClanché
What is another name for the LeClanché cell
Carbon zinc
Electrodes in cabron-zinc cell
carbon, zinc
Electrolyte for LeClanché cell
paste of ammonium chloride, manganese oxide, granulated carbon
Why do some primary batteries leak?
the zinc dissolves as it is used up
Alkaline cell electrodes
Zn, manganese oxide
Alkaline cell electrolyte
KOH in paste form
Alkaline cell voltage
1.5V
Alkaline vs LeClanché shelf life
alkaline has longer shelf life
Alkaline vs Leclanché cost
alkaline cost more
Mercury button cells elctrodes
mercuric oxide, zinc
Mercury button cells electrolyte
KOH
Mercury button cells voltage
1.35V
Silver Zinc button cells voltage
1.6V
Advantage of button cells
high energy density and long life
Disadvantage of button cells
cost more
Voltage range of lithium cells
1.9 to 3.6 V
Why is lithium used in batteries
it has a high affinity for oxygen
Solid LiOH voltage
1.9 V
Li ion battery with low current capacity
solid LiOH
Li battery with highest voltage
NaCl
What determines amount of current a cell can deliver
surface area of its plates
What determines amount of power a cell contains
volume and type of cell being used
Two voltage ratings for batteries
no load
normal load
Why is no load voltage greater
internal resistance
T or F: All cells have internal resistance
TRUE
Common type of secondary cell
lead-acid
Lead acid battery composition
lead plate
lead oxide plate
sulfuric acid
How is the specific gravity of the battery measured
with a hydrometer
When lead-acid battery is discharged, specific gravity will be
close to 1
When lead-acid battery is charged, specific gravity will be
close to 1.2
Discharge cycle
battery discharges stored electrons through a load connected to the battery terminals
What happens to the lead-acid electrolyte as the battery discharges
it becomes diluted as more water molecules form
Charge cycle
the battery is connected to a DC power supply or a generator and electrons flow back to the lead plate
What happens to the lead-acid electrolyte as the battery charges
sulfuric acid is reformed
As the battery ages or is overcharged what happens
the lead sulfate flakes off and can’t be used to reform the electrolyte
Once lead sulfate flakes touch the batteries plates what happens
the flakes cause a short circuit and the cell can’t operate
Nickel Iron batteries aka
Edison batteries
Advantage of Nickel Iron
can handle deep discharge without harm
Nicad batteries can produce
a large amount of current
NiCad cell voltage
1.2V per cell
Disadvantage of NiCad
memory accumulation
NIcCad electrodes
Nickel hydroxide w/graphite
Cadmium oxide
Nickel Metal Hydride cell voltage
1.2V (like NICad)
Nickel Iron electrodes
Nickel steel grid with powdered iron
Nicad electrolyte
21% KOH
Nickel Iron vs lead-acid energy density
Nickel iron is lower
Disadvantages of Nickel Iron
high cost
high internal resistance
Where are Nickel iron batteries used
portable safety equiepment
Ni metal hydride energy density vs NiCad
Ni metal has 40% more
Other advantages of Nickel metal hydride
not as much memory accumulation
environmentally friendly
What is replacing Nicad batteries
Nickel metal hydride batteries
Which secondary cells have high energy density for their size and weight
Litihium ion
Lithium ion cell voltage
3.6 V/cell
Do Li ion cells have memory accumulation problem?
No they do not
When batteries are connected in series what adds and what stays the same
voltage adds, current stays the same
When batteries are connected in parallel, what adds and what stays the same
current adds and voltage stays the same
Can we put batteries of different voltages in parallel
absolutely not
Internal resistance of batteries affects
their performance
What strikes a semiconductor to produce electricity in a solar cell
photon
Silicon solar cell open circuit voltage in direct sunlight
0.5 V
Semiconductors have _ valence electrons
4
Voltage of a solar cell depends on
type of material
Current of a solar cell depends on
surface area
Piezo is the Greek word for
pressure
Pressure of piezoelectricity is caused by
bending, twisting, stretching
Note 
Flashcard (63)