Swappable Fuel Cells ??

[BusyBee]

Petrol or diesel do indeed have a large energy density in practice, but unlike batteries, a can of petrol or diesel has no significant energy by itself.

A tank of fuel can be very dangerous in the event of mechanical damage just like sticking a knife through a lithium battery.
Once a tank of diesel becomes damaged the fuel gets exposed to air and will indeed burn.
Ignition will occur by contact with sparks or any other hot objects including friction between the object causing the damage to the fuel tank itself. This is why aircraft often turn into fire if they crash.

A damaged fuel tank on a moving vehicle will soon catch on fire if it has come loose and contacts the ground underneath.
An example of a friction ignited diesel tank.
https://www.independent.co.uk/news/train...24341.html

I see both sides on this but I think my main point would be that a tank of fuel is dormant without external influence but a Lithium battery can have an internal fault which initiates an explosion. Maybe in most cases the result of external effects not allowed for but I do remember from the past experience seeing fuel fires which were sorted quickly. Burning fuel in a tank will not usually spontaneously explode as there is absence of oxidiser to cause that (at least in a full tank) and a leak keeps the flame front away (I am presuming a bit here). Electric car batteries are usually in a fairly safe position but the effects of a physical rupture with a very high capacity battery? Liquid fuel will leak but does need to be ignited whereas a ruptured battery has capability of self ignition.

Tracy