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This might seem a very naive question. Maybe the comparison of electric vehicle to aircraft is hugely inappropriate. But I couldn't find a clear answer in web search.

Lithium-ion batteries have a high power-to-weight ratio, high energy efficiency and good high-temperature performance. Even then they are not preferred to be used in aircraft.

If safety is the concern, aren't there enough protection mechanisms which have enabled their widespread proliferation in electric vehicle market.

Why is the weight to power-to-weight advantage not being exploited by aerospace industry? What are the other aspects to be considered- extreme environmental conditions or so?

EDIT: OP has added in comments (but not here) that "I am referring to the regular usage of batteries in aircraft. Not for propulsion".

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    \$\begingroup\$ Did you miss the kerfuffle a couple of years ago with the Boeing 787 Dreamliner being grounded due to lithium battery issues? \$\endgroup\$
    – Kartman
    Jan 12 at 14:07
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    \$\begingroup\$ A fire on the ground is rather more survivable than a fire in the air. \$\endgroup\$
    – Neil_UK
    Jan 12 at 14:09
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    \$\begingroup\$ @DivyaK.S - Hi, I recommend (a) Doing some more research (it will take you a while!) about the history of the Boeing 787 batteries. (b) There may be more on Aviation.SE regarding battery certification (especially discussed after the topic in point (a)) that may be relevant. Overall, this seems like more of an "Aviation electronics" question, than an "Electronics in aviation" question, where commercial airplane certification requirements are an important factor, so Aviation.SE may be a more suitable home for your question (after doing research there). \$\endgroup\$
    – SamGibson ♦
    Jan 12 at 14:16
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    \$\begingroup\$ "Why is the weight to power-to-weight advantage not being exploited by aerospace industry?" This question feels like missing the forest for the trees. When you have a massive turbine engine for propulsion and an APU to provide the electricity most of the time, why do you care about power to weight ratio for the tiny battery? \$\endgroup\$
    – DKNguyen
    Jan 12 at 14:35
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    \$\begingroup\$ It sounds like you're comparing apples to oranges here. You're asking why lithium batteries are used in electric cars but not in combustion airplanes. If you want to compare cars to airplanes, it would make more sense to compare electric cars to electric airplanes, or combustion cars to combustion airplanes. \$\endgroup\$
    – Tanner Swett
    Jan 12 at 15:27

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Primarily because it is easier to escape from a burning car than it is to escape from a burning aircraft. That said, the 787 does utilize Lithium based batteries (although not for propulsion) and there have been issues resulting in design changes to reduce risk in the event of a battery fire such as containment and venting overboard.

2013 Boeing 787 Dreamliner grounding

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If you mean for propulsion, burning stuff still has much, much higher Specific energy than any battery. Also, there's the bonus of not having to carry around empty cells, once the energy is inside them gets used up.

  • "A typical energy content for kerosene is 42.8 MJ/kg" (source)
  • Li-Pol Specific energy is up to 158 Wh/Kg = 0.6 MJ/kg (source)

Notice that electric cars today still struggle to get ranges comparable to combustion ones. Also note that low temperature performance is an important factor. Even the Jet A-1 can freeze (at −47 °C) when flown over the poles.

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    \$\begingroup\$ Hi, Re: "If you mean for propulsion" No, the OP doesn't mean that. See their comment which has now been added into the question. \$\endgroup\$
    – SamGibson ♦
    Jan 12 at 15:41

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