Battery Technology 1 Applications using Batteries 2 Battery
Battery Technology 1
Applications using Batteries 2
Battery • Convert stored chemical energy into electrical energy • Reaction between chemicals take place • Consisting of electrochemical cells • Contains • Electrodes • Electrolyte 3
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 4
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 5
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 6
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) + 2 OH−(aq) → Zn. O(s) + H 2 O(l) + 2 e− [e° = -1. 28 V] 2 Mn. O 2(s) + H 2 O(l) + 2 e− → Mn 2 O 3(s) + 2 OH−(aq) [e° = 0. 15 V] • Overall reaction: Zn(s) + 2 Mn. O 2(s) → Zn. O(s) + Mn 2 O 3(s) [e° = 1. 43 V] 7
Zinc-Carbon Battery • Anode: zinc metal body (Zn) • Cathode: manganese dioxide (Mn. O 2) • Electrolyte: paste of zinc chloride and ammonium chloride dissolved in water • The half-reactions are: Zn(s) → Zn 2+(aq) + 2 e- [e° = -0. 763 V] 2 NH 4+(aq) + 2 Mn. O 2(s) + 2 e- → Mn 2 O 3(s) + H 2 O(l) + 2 NH 3(aq) + 2 Cl- [e° = 0. 50 V] • Overall reaction: Zn(s) + 2 Mn. O 2(s) + 2 NH 4 Cl(aq) → Mn 2 O 3(s) + Zn(NH 3)2 Cl 2 (aq) + H 2 O(l) [e° = 1. 3 V] 8
Primary Cell 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 9
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 10
Nickel-Cadmium Battery • Anode: Cadmium hydroxide, Cd(OH)2 • Cathode: Nickel hydroxide, Ni(OH)2 • Electrolyte: Potassium hydroxide, KOH • The half-reactions are: Cd+2 OH- → Cd(OH)2+2 e 2 Ni. O(OH)+Cd+2 e- → 2 Ni(OH)2+2 OH- • Overall reaction: 2 Ni. O(OH) + Cd+2 H 2 O→ 2 Ni(OH)2+Cd(OH)2 11
Nickel-Cadmium Battery • Maintain a steady voltage of 1. 2 v 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 12
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 nickelcadmium batteries is very limited 13
Lead-Acid Battery • Anode: Porous lead • Cathode: Lead-dioxide • Electrolyte: Sulfuric acid, 6 molar H 2 SO 4 • Discharging (+) electrode: Pb. O 2(s) + 4 H+(aq) + SO 42 -(aq) + 2 e- → Pb. SO 4(s) + 2 H 2 O(l) (-) electrode: Pb(s) + SO 42 -(aq) → Pb. SO 4(s) + 2 e • During charging (+) electrode: Pb. SO 4(s) + 2 H 2 O(l) → Pb. O 2(s) + 4 H+(aq) + SO 42 -(aq) + 2 e(-) electrode: Pb. SO 4(s) + 2 e- → Pb(s) + SO 42 -(aq) 14
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 15
Lead-Acid Battery • Advantages: • • • 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 16
Lithium-Ion Battery • Anode: Graphite • Cathode: Lithium manganese dioxide • Electrolyte: mixture of lithium salts • Lithium ion battery half cell reactions Co. O 2 + Li+ + e- ↔ Li. Co. O 2 Eº = 1 V Li+ + C 6+ e- ↔ Li. C 6 Eº ~ -3 V • Overall reaction during discharge Co. O 2 + Li. C 6 ↔ Li. Co. O 2 + C 6 Eoc = E+ - E- = 1 - (-3. 01) = 4 V 17
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 18
Lithium-Ion Battery • 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 19
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 $71 K - $94 K, Model X available in 2015 • 6000 employees • Cars built in Fremont, CA (San Francisco suburb) • 35, 000 units expected to sell globally in 2014 20
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 21
Tesla Model S • The 85 k. Wh 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 ~200 A Supercharging Station • 110 VAC or 240 VAC charging voltages • http: //www. teslamotors. com/goelectric#charging 22
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 23
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 4 X 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 24
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