Battery box from plywood

I’m going to build an internal e‑foil battery box from 6 mm marine plywood with fiberglass and epoxy on the outside. The only problem I see is that plywood has poor thermal conductivity, which may cause the battery to overheat. What do you think?

When you say “internal” - does that mean inside the board with a hatch or just a protective casing for the cells?

Why do you assume your battery will generate a lot
of heat that needs to be dissipated?

Inside a board with hatch.
12s10p 21700 middle-current elements. 50A max battery current expected, about 30A continuous.