Why? It will be hazzard for your own army. Chlorine trifluoride is insanely hard to work with and will not give any substantial advantage over explosives.
Chlorine trifluoride will react with close to everything there is and big part that can hold have problems with shocks(quartz) and temperature(wax)...
So from more simple not-so-risky shell production you would make hazard production on level of more tricky chemical weapons. Treated with fluorine gas: steel, iron, nickel, copper or alloys like monel or inconel, teflon can be used for vessels.
Teflon ignites at 180-200°C, fluorine gas from decomposition leaks through it, so shells metal still would need to be treated.
Most likely, only way to go would be to use steel shells treated with fluorine gas. Other options are hard to work, have worse physical properties and cost way more.But steel needs to be pure from many alloying metals and dry, one mistake and you have a disaster. This shells would need extra care not to be dropped or hit, if coating or walls of one shell are damaged, your solders better train to run fast.
Nice read about it.