You Do Need power plug adapter while traveling from Costa Rica to Cape Verde.

Here is Why You Need An Adapter

The outlet and plug type used in Cape Verde are C and F and in Costa Rica are A and B. This is how they look like.

Costa Rica

In Costa Rica, outlets of type A and B are in use.

Type A

Type B

Cape Verde

In Cape Verde, outlets of type C and F are in use.

Type C

Type F