You Do Need power plug adapter while traveling from Liberia to Cocos (Keeling) Islands.

Here is Why You Need An Adapter

The outlet and plug type used in Cocos (Keeling) Islands is I and in Liberia are A, B, C and F. This is how they look like.

Liberia

In Liberia, outlets of type A, B, C and F are in use.

Type A

Type B

Type C

Type F

Cocos (Keeling) Islands

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

Type I