batteries physics. power cell device for storing chemical energy and then releasing it in the form...
Post on 19-Dec-2015
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Power Cell
Device for storing chemical energy and then releasing it in the form of electricity when current is needed
Parts of a Power Cell
1. Anode –Metal–High affinity for oxygen–Draw oxygen from cathode to become oxidized
Parts of a Cell
2. Cathode–Metallic oxide–Lower affinity for oxygen–Becomes reduced when oxygen is taken
Parts of a Cell
4.Current Collector – Connected to anode and cathode– Good conductor
5.Electrolyte– Usually liquid (ionized water, acid/base)– “Domino Effect” of oxygen from cathode to
anode
Operation of Power Cell
As anode becomes oxidized, an electron must be given up
Electron flows through anode’s current collector through circuit (outside of battery) as electrical current back to cathode’s current collector
Alkaline
1.5 V: lose voltage graduallyHigh Capacity (electrical energy)
– Last longer5 year shelf-lifeBetter in high drain devices than C-Zn
Lithium
Started off as button cellAnode: lithiumCathode: magnesium dioxide3 V: Takes up less space with
more voltage
Recharging Batteries
A current from an outside source is pushed through the cell in the opposite direction from the original current
Oxygen goes from anode to cathode
Nickel-Cadmium (Ni-Cd)
1.2 VoltsLow capacityMemory effect (Rechargeable)
– If you re-charge the battery too soon, you lower its capacity
Nickel-Metal Hydride (NiMH)
1.2 VBest rechargeable batteryHigh CapacityGood for high drainage
devices
Lithium-Ion
3.6 VSlow-loss of charge (5% per month)Best energy to weight ratioNo memory effectPopular for portable electronics (cell
phones, IPod)
Ideal Power Cell
Unlimited shelf lifeMaximum energy for minimum
spaceLight weightRechargeable (fast and
complete)
Ideal Power Cell (cont.)
Consumer proof/SafeResistant to environmental
extremesCostPerform in a variety of different
applications