3. ⢠Convert stored chemical
energy into electrical energy
⢠Reaction between chemicals
take place
⢠Consisting of electrochemical
cells
⢠Contains
â Electrodes
â Electrolyte
Battery
4. ⢠Cathode
â Positive terminal
â Chemical reduction occurs (gain electrons)
⢠Anode
â Negative terminal
â Chemical oxidation occurs (lose electrons)
⢠Electrolytes allow:
â Separation of ionic transport and electrical transport
â Ions to move between electrodes and terminals
â 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) + 2OHâ
(aq) â ZnO(s) + H2O(l) + 2eâ [e° = -1.28 V]
2MnO2(s) + H2O(l) + 2eâ â Mn2O3(s) + 2OHâ
(aq) [e° = 0.15 V]
⢠Overall reaction:
Zn(s) + 2MnO2(s) â 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:
â Electrodes undergo the
opposite process than
discharging
â Cathode is oxidized and
produces electrons
â 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:
â This chemistry is reliable
â Operate in a range of temperatures
â Tolerates abuse well and performs well after long periods
of storage
⢠Disadvantages:
â It is three to five times more expensive than lead-acid
â 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:
â It has a high specific energy (number of hours of operation for
a given weight)
â Huge success for mobile applications such as phones and
notebook computers
⢠Disadvantages:
â Cost differential
⢠Not as apparent with small batteries (phones and computers)
⢠Automotive batteries are larger, cost becomes more significant
â Cell temperature is monitored to prevent temperature extremes
â 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
â No periodic discharge needed
â No memory
⢠Energy density of lithium-ion is three times of the
standard lead acid
⢠Cost of battery
â Almost twice of standard nickel-cadmium (40%)
â Five times that of the standard lead acid
Lithium Rechargeable Batteries and Tesla
19. ⢠The 85 kWh battery pack contains
â 7,104 lithium-ion battery cells
â 16 modules wired in series
â 14 in the flat section and 2 stacked on the
front
â Each module has six groups of 74 cells
wired in parallel
â 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
â Reduced charging time
â Increase amount of energy stored for size and weight
â Increase life span, number of charges
â Reduce Cost
⢠Any predictions on where we might be in the future vs
today?
â Toyotaâs goal 4X today battery energy density, and 600 mile
range for 2020
⢠What cars, like Tesla, might be able to do in the future?
â Higher performance cars
â Faster re-charge time
â Increased mileage range on a charge
â Higher convenience level, similar to gas powered cars, more
affordable
Conclusion