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Chemistry of Batteries. Galvanic CellsDaniell CellRechargeable Batteries. Nickel Cadmium(NiCd). NiCd batteries are the most commonly used rechargeable batteriesUsed where long life, high discharge rate and economical price are importantCadmium anode, nickel-hydroxide cathode, alkaline electrolyteHigh currents at relatively constant voltage Low capacity (450-900 mAh)Low energy density (40-60 Wh/kg)Low shelf life, discharges quickly (20% per month)High cycle life (1550)Moderate overch24
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1. Consumer Batteries Derrick Chou
Derek Juang
Jed Kim
Julia Wang
EE164, Fall 2002: with Dr. Ybarra
2. Chemistry of Batteries Galvanic Cells
Daniell Cell
Rechargeable Batteries
3. Nickel Cadmium(NiCd) NiCd batteries are the most commonly used rechargeable batteries
Used where long life, high discharge rate and economical price are important
Cadmium anode, nickel-hydroxide cathode, alkaline electrolyte
High currents at relatively constant voltage
Low capacity (450-900 mAh)
Low energy density (40-60 Wh/kg)
Low shelf life, discharges quickly (20% per month)
High cycle life (1550)
Moderate overcharge tolerance
Very sensitive to memory effect
Low cost
Contains toxic material, need special disposal
4. Nickel Metal Hydride (NiMH) Provides incremental improvements in capacityover the NICAD at the expense of reduced cycle life and lower load current
Hydrogen storage metal alloy anode, nickel oxide cathode, potassium hydroxide electrolyte
30-40% greater capacity than NiCd (1100-1600 mAh)
Moderate energy density (60-80 Wh/kg)
Low shelf life, discharges quickly (30% per month)
High cycle life (500-600)
Low overcharge tolerance
Moderate cost
5. Lithium Ion (Li Ion) Fragile technology requiring protector circuit for overcharge (when charged, voltage still rises)
Used where very high energy density is needed and cost is secondary
High capacity(50% more than NiCd)
Light weight (20-35% less than NiMH)
Long shelf life (wont discharge)
Memory-effect resistant
Expensive
Lifespan is 12-18 months
Environmentally Friendly
6. Lithium Polymer (Li Poly) Most advanced battery technology
Only hybrid versions are available in todays market
More resistant to overcharge (less chance for electrolyte leakage)
Currently no cost advantage over Li Ion, but potential for lower cost
Can be made into any shape, any size (ultra slim geometry for cell phones)
7. Rechargeable Battery Comparison
9. Lead Batteries The battery industry is the largest consumer of lead in the world.
98 percent of a lead battery is recyclable.
Lead emissions from battery manufacturing account for less than one percent of the country's total estimatedlead emissions, even though battery manufacturing accounts for more than 80 percent of lead usage in the country.
Body takes in lead in two ways:
1. Ingestion
2. Inhalation
10. Recycling Chart
11. Lead Acid Battery
Closed Loop Life Cycle
60 to 80 percent recycled lead and plastic
Indefinite Cycle
13. Recycling Process Hammermill breaks it apart.
Plastic melt then make small pellets.
Lead melt and remove impurities.
Sulfuric Acid
1. Neutralized
2. Convert to Sodium Sulfate
14. Federal Hazardous Waste Requirement
Ignitability, Corrosivity, Reactivity, Toxicity.
Hazardous if one or more of the above characteristics are present.
15. RBRC Rechargeable Batteries Recycling Corporation
Nickel Cadmium (Ni-Cd)
Nickel Metal Hydride (Ni-MH)
Lithium Ion (Li-ion)
Small Sealed Lead (Pb)*
16. Nickel-Cadmium Highly toxic, carcinogenic
Can accumulate up marine food webs
Therefore affect people who eat seafood
It may lead to potentially fatal kidney and liver problems, brittle bones, and reproductive disorders
17. Lithium Ion/Lithium Polymer
Completely discharged lithium batteries can be safely disposed of in the landfills.
18. Ignitability It is a liquid and has a flash point of less than 140 degrees ;
It is not a liquid and is capable, under standard temperature and pressure, of causing fire through friction, absorption of moisture, or spontaneous chemical changes and, when ignited, burns so vigorously and persistently that it creates a hazard;
It is an oxidizer (as defined in Title 29 CFR 1910.1200(C)).
19. Corrosivity
if a representative sample of the waste is aqueous and has a pH less than or equal to 2 or greater than or equal to 12.5.
20. Reactivity It is normally unstable and readily undergoes violent changes without detonating;
It reacts violently with water;
It forms potentially explosive mixtures with water;
When mixed with water, it generates toxic gases, vapors, or fumes in a quantity sufficient to present a danger to human health or the environment;
It is a cyanide or sulfide bearing waste which, when exposed to pH conditions between 2 and 12.5, can generate toxic gases, vapors, or fumes in a quantity sufficient to present a danger to human health or the environment; or
It is capable of detonation or explosive decomposition or reaction at standard temperature and pressure.
21. Toxicity
22. Beyond Batteries Fuel Cells (Micro-Fuel Cells)
Endlessly Rechargable
Hydrogen reacting with oxygen in air
Water as waste product