  The one-dimensional Kondo lattice model with attractive interaction among the
conduction electrons is analyzed in the case of half-filling. It is shown that
there are three distinct phases depending on the coupling constants of the
model. Two phases have a spin and charge gap. While one shows a clear
separation of the spin and charge excitation spectrum the other phase may be
characterized as a band insulator type where both excitations are due to
two-particle states. The third phase is gapless in both channels and has quasi
long-range order in the spin and charge density wave correlation. In this phase
the spin and charge excitations have again a clearly separated spectrum. For
the analysis we discuss first two limiting cases. Then a density matrix
renormalization group calculation on finite systems is applied to determine the
phase diagram and the correlation functions in the gapped and gapless phase for
general couplding constants.
