  The electrodissolution of p-type silicon in a fluoride-containing electrolyte
is a prominent electrochemical oscillator with a still unknown oscillation
mechanism. In this article, we present a study of its dynamical states
occurring in a wide range of the applied voltage - external resistance
parameter plane. We provide evidence that the system possesses inherent
birhythmicity, and thus at least two distinct feedback loops promoting
oscillatory behaviour. The two parameter regions in which the different limit
cycles exist are separated by a band in which the dynamics exhibit bistability
between two branches with different multimode oscillations. Following the
states along one path through this bistable region, one observes that each
branch undergoes a different transition to chaos, namely a period-doubling
cascade and a quasiperiodic route with a torus-breakdown, respectively, making
Si electrodissolution one of the few experimental systems exhibiting
bichaoticity.
