Naked Science Forum
General Science => Question of the Week => Topic started by: Lewis Thomson on 11/04/2022 12:28:40
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Barry wants to know,
'What causes degradation in electric car batteries, and what are the upcoming developments in EV technology?
What do you think? Leave your sparking suggestions in the comments below...
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Lithium batteries generally develop internal short circuits. Initially seen as a decrease in charge retention, followed by an increase in recharge time due to overheating, and finally spontaneous ignition which wrecked a couple of early Boeing 787s.
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"The four suspected renegades responsible for capacity loss and the eventual end-of-life of the Li-ion battery are:
1. Mechanical degradation of electrodes or loss of stack pressure in pouch-type cells. Careful cell design and correct electrolyte additives minimize this cause.
2. Growth of solid electrolyte interface (SEI) on the anode. A barrier forms that obstructs the interaction with graphite, resulting in an increase of internal resistance. SEI is seen as a cause for capacity loss in most graphite-based Li-ion when keeping the charge voltage below 3.92V/cell. Electrolyte additives reduce some of the effect.
3. Formation of electrolyte oxidation (EO) at the cathode that may lead to a sudden capacity loss. Keeping the cells at a voltage above 4.10V/cell and at an elevated temperature promotes this phenomenon.
4. Lithium-plating on the surface of the anode caused by high charging rates." (https://batteryuniversity.com/article/bu-808b-what-causes-li-ion-to-die)
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SEI is seen as a cause for capacity loss in most graphite-based Li-ion when keeping the charge voltage below 3.92V/cell........
3. Formation of electrolyte oxidation (EO) at the cathode that may lead to a sudden capacity loss. Keeping the cells at a voltage above 4.10V/cell and at an elevated temperature promotes this phenomenon.
So you need to keep your battery in the region of 3.92 - 4.10 volt per cell. And don't use fast chargers. But it will degrade anyway if you don't use it.
I don't see the word "convenient" or "practical" applied to this mode of transport just yet, but it's only been around for 190 years. Unlike a horse, which recharges itself and lives outdoors.
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Unlike a horse, which recharges itself and lives outdoors.
The impracticalities of horses were well documented.
https://www.historic-uk.com/HistoryUK/HistoryofBritain/Great-Horse-Manure-Crisis-of-1894/
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But you can grow marvellous roses on their emissions.
The problem with horses, steam trains, cars, and domestic coal fires has never been the exhaust per se, but the fact that people live and work in cities. Thanks to offshoring of all manufacturing, the closure of mines and refineries, and home working of every other activity, there is no need for high density accommodation any more, so we could keep a horse and grow our own vegetables whilst the rest of the world drags itself into the 19th century.
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But you can grow marvellous roses on their emissions.
The problem with horses, steam trains, cars, and domestic coal fires has never been the exhaust per se, but the fact that people live and work in cities. Thanks to offshoring of all manufacturing, the closure of mines and refineries, and home working of every other activity, there is no need for high density accommodation any more, so we could keep a horse and grow our own vegetables whilst the rest of the world drags itself into the 19th century.
Things like mining and manufacturing were largely replaced by service industries- and those are only practical in cities.
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Things like mining and manufacturing were largely replaced by service industries- and those are only practical in cities.
Not many cars are built in offices, nor is much food grown in cities. And office workers have no need to be close to one another nowadays. Many "service" industries are just parasitic organisations for gambling with other people's money.
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Not many cars are built in offices, nor is much food grown in cities.
Well spotted.
Did you somehow think anyone had said otherwise?
Many "service" industries are just parasitic organisations for gambling with other people's money.
Yes, but the village hospital or hamlet university isn't a great idea (unless it has backup from something bigger).
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Yes, but the village hospital or hamlet university isn't a great idea
The Open University has prospered with a negligible campus, and for the last couple of years most academic institutions have conducted the majority of their undergraduate teaching by video link. None of my research work depended on the proximity of shops and other offices. The biggest problems facing most hospital patients and administrators are access and car parking, which become less severe if the hospital is not in a city.