Advanced module and ship upgrades, including shields are research at the tech lab.
— In-game description
The Tech Lab is one of three research labs. Its primary purpose is to research new Technology, such as shields, weapon boosts, cargo enhancers, and thrusters. It can't, however, research blueprint technology, such as rechargeable shields.
Players often avoid putting armor or shields on these labs to reduce the repair time in the event they are destroyed.