General solution of scalar field cosmology with a (piecewise)   exponential potential
  We study in detail the general solution for a scalar field cosmology with an exponential potential, correcting some imprecisions, encountered previously in the literature. In addition, we generalize this solution for a piecewise exponential potential, which is continuous, but not smooth (with cusps). 
A.A. Andrianov, F. Cannata and A.Yu. Kamenshchik
gr-qc hep-th