3. • Convert stored chemical
energy into electrical energy
• Reaction between chemicals
take place
• Consisting of electrochemical
cells
• Contains
– Electrodes
– Electrolyte
Battery
4. • Cathode
– Positive terminal
– Chemical reduction occurs (gain electrons)
• Anode
– Negative terminal
– Chemical oxidation occurs (lose electrons)
• Electrolytes allow:
– Separation of ionic transport and electrical transport
– Ions to move between electrodes and terminals
– Current to flow out of the battery to perform work
Electrodes and Electrolytes
5. • Battery has metal or plastic
case
• Inside case are cathode, anode,
electrolytes
• Separator creates barrier
between cathode and anode
• Current collector brass pin in
middle of cell conducts
electricity to outside circuit
Battery Overview
6. • One use (non-
rechargeable/disposable)
• Chemical reaction used, can
not be reversed
• Used when long periods of
storage are required
• Lower discharge rate than
secondary batteries
• Use:
smoke detectors, flashlights,
remote controls
Primary Cell
7. • Alkaline batteries name came from the electrolyte in an alkane
• Anode: zinc powder form
• Cathode: manganese dioxide
• Electrolyte: potassium hydroxide
• The half-reactions are:
Zn(s) + 2OH−
(aq) → ZnO(s) + H2O(l) + 2e− [e° = -1.28 V]
2MnO2(s) + H2O(l) + 2e− → Mn2O3(s) + 2OH−
(aq) [e° = 0.15 V]
• Overall reaction:
Zn(s) + 2MnO2(s) → ZnO(s) + Mn2O3(s) [e° = 1.43 V]
Alkaline Battery
9. • Alkaline Battery
• Zinc powered, basic electrolyte
• Higher energy density
• Functioning with a more stable
chemistry
• Shelf-life: 8 years because of
zinc powder
• Long lifetime both on the shelf
and better performance
• Can power all devices high and
low drains
• Use:
Digital camera, game console, remotes
• Zinc-Carbon Battery
• Zinc body, acidic electrolyte
• Case is part of the anode
• Zinc casing slowly eaten
away by the acidic electrolyte
• Cheaper then Alkaline
• Shelf-life: 1-3 years because
of metal body
• Intended for low-drain
devices
• Use:
Kid toys, radios, alarm clocks
Primary Cell
10. • Rechargeable batteries
• Reaction can be readily
reversed
• Similar to primary cells
except redox reaction can be
reversed
• Recharging:
– Electrodes undergo the
opposite process than
discharging
– Cathode is oxidized and
produces electrons
– Electrons absorbed by anode
Secondary Cells
12. • Maintain a steady voltage of 1.2v per cell until completely
depleted
• Have ability to deliver full power output until end of cycle
• Have consistent powerful delivery throughout the entire
application
• Very low internal resistance
• Lower voltage per cell
Nickel-Cadmium Battery
13. • Advantages:
– This chemistry is reliable
– Operate in a range of temperatures
– Tolerates abuse well and performs well after long periods
of storage
• Disadvantages:
– It is three to five times more expensive than lead-acid
– Its materials are toxic and the recycling infrastructure for
larger nickel-cadmium batteries is very limited
Nickel-Cadmium Battery
15. • The lead-acid cells in automobile batteries are wet
cells
• Deliver short burst of high power, to start the engine
• Battery supplies power to the starter and ignition
system to start the engine
• Battery acts as a voltage stabilizer in the electrical
system
• Supplies the extra power necessary when the
vehicle's electrical load exceeds the supply from the
charging system
Lead-Acid Battery
17. • Advantages:
– It has a high specific energy (number of hours of operation for
a given weight)
– Huge success for mobile applications such as phones and
notebook computers
• Disadvantages:
– Cost differential
• Not as apparent with small batteries (phones and computers)
• Automotive batteries are larger, cost becomes more significant
– Cell temperature is monitored to prevent temperature extremes
– No established system for recycling large lithium-ion batteries
Lithium-Ion Battery
18. • High energy density - potential for yet higher
capacities
• Relatively low self-discharge, less than half of
nickel-based batteries
• Low Maintenance
– No periodic discharge needed
– No memory
• Energy density of lithium-ion is three times of the
standard lead acid
• Cost of battery
– Almost twice of standard nickel-cadmium (40%)
– Five times that of the standard lead acid
Lithium Rechargeable Batteries and Tesla
19. • The 85 kWh battery pack contains
– 7,104 lithium-ion battery cells
– 16 modules wired in series
– 14 in the flat section and 2 stacked on the
front
– Each module has six groups of 74 cells
wired in parallel
– The six groups are then wired in series
within the module
• How many AA batteries does it at take to
power the Model S ~35,417
• Weigh approximately 320 kg
• 8 year infinite mile warranty on battery
• 350 to 400 VDC at ~200A
Supercharging Station
• 110 VAC or 240 VAC charging voltages
• http://www.teslamotors.com/goelectric#c
harging
Tesla Model S
20. • Companies or researchers are improving batteries
– Reduced charging time
– Increase amount of energy stored for size and weight
– Increase life span, number of charges
– Reduce Cost
• Any predictions on where we might be in the future vs
today?
– Toyota’s goal 4X today battery energy density, and 600 mile
range for 2020
• What cars, like Tesla, might be able to do in the future?
– Higher performance cars
– Faster re-charge time
– Increased mileage range on a charge
– Higher convenience level, similar to gas powered cars, more
affordable
Conclusion
