You Do Need power plug adapter while traveling from Cocos (Keeling) Islands 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 Cocos (Keeling) Islands is I. This is how they look like.

Cocos (Keeling) Islands

In Cocos (Keeling) Islands, outlets of type I are in use.

Type I

Cape Verde

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

Type C

Type F