Batteries

Types, advantages, and disadvantages

1. Batteries Periyanayaga Kristy.A , Ph.D. Research S cholar SRM Universtiy Chennai

2. Applications using Batteries

3. Convert stored chemical energy into electrical energy R eaction between chemicals take place C onsisting of electrochemical cells Contains Electrodes Electrolyte Battery

4. Cathode Positive terminal C hemical reduction occurs (gain electrons ) Anode Negative terminal Chemical oxidation occurs (lose electrons) Electrolytes allow: S eparation 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) + H 2 O (l) + 2e − [e° = -1.28 V ] 2MnO 2(s) + H 2 O (l) + 2e − → Mn 2 O 3(s) + 2OH − ( aq ) [e° = 0.15 V ] Overall reaction : Zn (s) + 2MnO 2(s) → ZnO (s) + Mn 2 O 3(s) [e° = 1.43 V ] Alkaline Battery

8. Anode:  zinc metal body (Zn ) Cathode: manganese dioxide (MnO 2 ) Electrolyte: paste of zinc chloride and ammonium chloride dissolved in water The half-reactions are: Zn(s) → Zn 2 + ( aq ) + 2e - [ e° = -0.763 V ] 2NH 4 + (aq) + 2MnO 2 (s) + 2e -   → Mn 2 O 3 (s ) + H 2 O(l) + 2NH 3 (aq) + 2Cl - [e ° = 0.50 V ] Overall reaction : Zn( s ) + 2MnO 2 ( s ) + 2NH 4 Cl( aq ) → Mn 2 O 3 ( s ) + Zn(NH 3 ) 2 Cl 2  ( aq ) + H 2 O( l ) [e° = 1.3 V]a Zinc-Carbon 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 C athode is oxidized and produces electrons Electrons absorbed by anode Secondary Cells

11. 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+2H 2 O→2Ni(OH) 2 +Cd(OH) 2 Nickel-Cadmium Battery

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 T olerates 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

14. Anode:  Porous lead Cathode: Lead-dioxide Electrolyte: Sulfuric acid, 6 molar H 2 SO 4 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 ) Lead-Acid 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

16. Anode: Graphite Cathode: L ithium manganese dioxide Electrolyte: mixture of lithium salts Lithium ion battery half cell reactions CoO 2 + Li + + e - ↔ LiCoO 2 E º = 1V Li + + C 6 + e - ↔ LiC6 E º ~ - 3V Overall reaction during discharge CoO 2 + LiC 6 ↔ LiCoO 2 + C 6 E oc = E + - E - = 1 - (-3.01) = 4V Lithium-Ion 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 N ot as apparent with small batteries (phones and computers) Automotive batteries are larger, cost becomes more significant C ell 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 N o periodic discharge needed No memory E nergy density of lithium-ion is three times of the standard lead acid Cost of battery A lmost twice of standard nickel-cadmium (40%) F ive 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#charging Tesla Model S

20. C ompanies 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 T esla, might be able to do in the future? Higher performance cars Faster re-charge time I ncreased mileage range on a charge Higher convenience level, similar to gas powered cars, more affordable Conclusion