Recall that a p-divisible group G has the defining properties that pid G:G→G is an epimorphism with finite kernel satisfying G=∪ jkerp jid G.
Now let A be any commutative algebraic k-group such that pid A:A→A is an epimorphism. Then
A(p):=\cup_j ker \,p^j \,id_A
is a p-divisible group.