Firewall for Trunk w/ Nitrous and battery!

Ok so to put it simply trunk has battery on the left nitrous on the right, I know I need to to put a firewall in so whats the best, safe but light material to use? Do I need to put up a partition between the battery and nos or should I put a box around 1 of them? I was thinking a box and kill switch for the battery. Do I need a fuel cell to do this? This is for the strip only and I am a new to it so I humbly ask for your opinions!
Thanks!