  If L is an oriented link with $n$ components, then the rank of its Khovanov
homology is at least $2^n$. We classify all the links whose Khovanov homology
with Z/2-coefficients achieves this lower bound, and show that such links can
be obtained by iterated connected sums and disjoint unions of Hopf links and
unknots. This gives a positive answer to a question asked by Batson and Seed.
