We are concerned with the global existence and decay rates of large
solutions for the Poisson--Nernst--Planck equations. Based on careful
observation of algebraic structure of the equations and using the
weighted Chemin--Lerner type norm, we obtain the global existence and
optimal decay rates of large solutions without requiring the summation
of initial densities of a negatively and positively charged species is
small enough. Moreover, the large solution is obtained for initial data
belonging to the low regularity Besov spaces with different regularity
and integral indices for the different charged species, which indicates
more specific coupling relations between the negatively and positively
charged species.