1. Battery Technology
Cheryl Salmonson
10/6/14

2. Applications using Batteries

3. Battery Convert stored chemical energy into electrical energy
Reaction between chemicals take place
Consisting of electrochemical cells
Contains
Electrodes
Electrolyte

4. Electrodes and Electrolytes
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
Think of questions to ask the class
Different kinds of batteries, chemistry behind them
Why one type over another in various applications
Biggest restrictions, thing that need improving

5. Battery Overview 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

6. Primary Cell 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
Electrochemical reactions are non-reversible materials in the electrodes are utilized, therefore cannot regenerate electricity

7. Alkaline Battery
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° = 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]

8. Zinc-Carbon Battery Anode: zinc metal body (Zn)
Cathode: manganese dioxide (MnO2)
Electrolyte: paste of zinc chloride and ammonium chloride dissolved in water
The half-reactions are:
Zn(s) → Zn2+(aq) + 2e- [e° = V]
2NH4+(aq) + 2MnO2(s) + 2e-  → Mn2O3(s) + H2O(l) + 2NH3(aq) + 2Cl- [e° = 0.50 V]
Overall reaction:
Zn(s) + 2MnO2(s) + 2NH4Cl(aq) → Mn2O3(s) + Zn(NH3)2Cl2 (aq) + H2O(l) [e° = 1.3 V]

9. Primary Cell Alkaline Battery Zinc-Carbon 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 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

10. Secondary Cells 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

11. Nickel-Cadmium Battery
Anode: Cadmium hydroxide, Cd(OH)2
Cathode: Nickel hydroxide, Ni(OH)2
Electrolyte: Potassium hydroxide, KOH
The half-reactions are:
Cd+2OH- → Cd(OH)2+2e-
2NiO(OH)+Cd+2e- →2Ni(OH)2+2OH-
Overall reaction:
2NiO(OH) + Cd+2H2O→2Ni(OH)2+Cd(OH)2

12. Nickel-Cadmium Battery
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

13. Nickel-Cadmium Battery
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

14. Lead-Acid Battery Anode: Porous lead Cathode: Lead-dioxide
Electrolyte: Sulfuric acid, 6 molar H2SO4
Discharging (+) electrode: PbO2(s) + 4H+(aq) + SO42-(aq) + 2e- → PbSO4(s) + 2H2O(l)  (-) electrode: Pb(s) + SO42-(aq) → PbSO4(s) + 2e- 
During charging  (+) electrode: PbSO4(s) + 2H2O(l) → PbO2(s) + 4H+(aq) + SO42-(aq) + 2e-  (-) electrode: PbSO4(s) + 2e- → Pb(s) + SO42-(aq)

15. Lead-Acid Battery
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

16. Lead-Acid Battery Advantages: Disadvantages:
Batteries of all shapes and sizes, available in
Maintenance-free products and mass-produced
Best value for power and energy per kilowatt-hour
Have the longest life cycle and a large environmental advantage
Ninety-seven percent of the lead is recycled and reused in new batteries
Disadvantages:
Lead is heavier compared to alternative elements
Certain efficiencies in current conductors and other advances continue to improve on the power density of a lead-acid battery's design

17. Lithium-Ion Battery Anode: Graphite Cathode: Lithium manganese dioxide
Electrolyte: mixture of lithium salts
Lithium ion battery half cell reactions
CoO2 + Li+ + e- ↔ LiCoO2 Eº = 1V
Li+ + C6+ e- ↔ LiC6 Eº ~ -3V
Overall reaction during discharge
CoO2 + LiC6 ↔ LiCoO2 + C6
Eoc = E+ - E- = 1 - (-3.01) = 4V

18. Lithium-Ion Battery Ideal material
Low density, lithium is light
High reduction potential
Largest energy density for weight
Li-based cells are most compact ways of storing electrical energy
Lower in energy density than lithium metal, lithium-ion is safe
Energy density is twice of the standard nickel-cadmium 
No memory and no scheduled cycling is required to prolong battery life 

19. Lithium-Ion Battery Advantages: Disadvantages:
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

20. Intro to Tesla Motors Produces and Sells Electric Cars Founded: 2003
Headquarters: Palo Alto, California
Servers: US, Canada, Western Europe, Middle
East, China, Japan, Australia, New Zealand
Model S $71K - $94K, Model X available in 2015
6000 employees
Cars built in Fremont, CA (San Francisco suburb)
35,000 units expected to sell globally in 2014

21. Lithium Rechargeable Batteries and Tesla
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

22. Tesla Model S 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
Battery energy can store to the equivalent number of gallons gas (energy) – do math on board

23. Tesla’s New Gigafactory
Opens 2017, Reno, Nevada
Employ up to 6,500 people and pay ~ $25/hr
Builds lithium-ion batteries
Cost to build Gigafactory
$5 Billion
Nevada pitching in $1+ Billion in incentives
$100 billion economic benefit over 20 years
Factory will help Tesla move closer to mass producing $35,000 car with 200 mile range
So this is an awesome project…. But to truly appreciate the project we have to understand the science behind it

24. Conclusion 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