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The best way to compare batteries is energy density per unit mass, energy input and output per unit cost, and cost of production/charging. Long chain hydrocarbo

The best way to compare batteries is energy density per unit mass, energy input and output per unit cost, and cost of production/charging. Long chain hydrocarbons have a much higher density than Li and are easy to pump and store and work in existing vehicles, but a higher cost of production and they are essentially one time use, non rechargeable since the discharge mechanism is combustion. The ideal solution would be efficient solar bioreactors where bioengineered algea converted solar energy into fats as a bioproduct of a photosynthetic process sequester CO2 that could be esterfied into alkanes or that directly produced alkanes. Long chain alkanes, my understanding is, are not toxic to life. It is the short chain stuff and aromatic ring based stuff like benzene that is hazardous. https://sfamjournals.onlinelibrary.wiley.com/doi/10.1111/1751-7915.12423 https://sfamjournals.onlinelibrary.wiley.com/doi/10.1111/175...

kragen 5y ago
That's a valid way to look at it if you think of the battery as analogous to the kerosene, rather than the tank. (BTW, lithium-ion batteries don't contain metallic lithium, so the much higher energy density of Li is not in play here.) I was thinking of the species that are created and destroyed within batteries as it's charged and discharged, like lead and lead dioxide, as being more closely analogous to the kerosene. Algae have very low capital costs but also fairly low photonic efficiency; it's reasonable to expect non-algae-based designs to be superior. (BTW, you can't esterify things into alkanes; alkanes aren't esters.) You're right about the toxicity profiles, although even things like hexane and octane are relatively low toxicity; hexane's oral LD50 is like tens of grams per kilogram, but they have higher toxicities if you breathe or inject them.
- morpheos137 5y ago
  Ok. I was thinking of things like biodiesel. My understanding is that involves an esterfication process but I read about it 10 years ago and never took orgo. I accept esters are not alkanes my ignorance shows...thanks for correcting the record for other readers. I was using Li as shorthand for Litium Ion batteries which I assume contain salts or oxides or hydrides of lithium. I know it is not elemental lithium. My point was that H-C bonds contain more energy than whatever is in Li batteries in the charged state per mol.

kragen 5y ago

That's a valid way to look at it if you think of the battery as analogous to the kerosene, rather than the tank. (BTW, lithium-ion batteries don't contain metallic lithium, so the much higher energy density of Li is not in play here.) I was thinking of the species that are created and destroyed within batteries as it's charged and discharged, like lead and lead dioxide, as being more closely analogous to the kerosene. Algae have very low capital costs but also fairly low photonic efficiency; it's reasonable to expect non-algae-based designs to be superior. (BTW, you can't esterify things into alkanes; alkanes aren't esters.) You're right about the toxicity profiles, although even things like hexane and octane are relatively low toxicity; hexane's oral LD50 is like tens of grams per kilogram, but they have higher toxicities if you breathe or inject them.

morpheos137 5y ago
Ok. I was thinking of things like biodiesel. My understanding is that involves an esterfication process but I read about it 10 years ago and never took orgo. I accept esters are not alkanes my ignorance shows...thanks for correcting the record for other readers. I was using Li as shorthand for Litium Ion batteries which I assume contain salts or oxides or hydrides of lithium. I know it is not elemental lithium. My point was that H-C bonds contain more energy than whatever is in Li batteries in the charged state per mol.