Lithium Ion batteries are usually very safe if used correctly.
but many batteries has not temperature pin .
And many batteries DO have a temperature pin.
If temperature is an issue then it is sensible to use a battery with a built in temperature sensor.
If desired, as an alternative to using a sensor-equipped battery, you could add a sensor to a sensorless battery pack by adding an external thermistor in good thermal contact with the battery. If you are unable to assess if the contact is thermally adequate then using an already-equipped battery would be wise.
LiIon battery operating range is typically approximately in the 0C - 60C range - but may be different - refer to the data sheet of the battery you are using. If you do not have a data sheet and are concerned about safety aspects then instead use a battery for which you do have a data sheet.
Some areas in vehicles are subject to more extreme temperatures than others.
On the firewall in the engine compartment is a traditional mounting place for auxiliary equipment and also known for very high temperatures.
Somewhere in the passenger compartment away from heat sources is liable to be preferable. If you are extremely concerned then it is possible to mount the battery in a flame and explosion 'resistant' housing.
Is aluminium enclosure suitable as a protector?
There are too many variables for a generic one-size-fits-all answer.
It would be possible to make an aluminium housing for a given battery, but if I was wishing to make one I'd tend to use steel of some sort.
Steel
Has a higher melting point,
Is less liable to burn in extreme cases (aluminium makes a nice rocket fuel once it gets going).
Is more liable to maintain strength at temperature.
Is probably also cheaper but that is not too relevant for small one-off jobs.
A proper design needs a good understanding of the issues involved - including temperature, pressure, duration and energy. And perhaps some other factors as well.
The chances of a fire occurring with a proper electrical design are small.