Galvanostatic conditions large current densities

From Fig. 18b it is clear that under galvanostatic conditions the limit cycle coexists with a stationary state at high overpotentials. The latter is the only attractor at large current densities. Hence, when the current density is increased above the value of the saddle-loop bifurcation, the potential jumps to a steady state far in the anodic region. Once the system has acquired the anodic steady state, it will stay on this branch as the current density is lowered until the stationary state disappears in a saddle-node bifurcation. 

Galvanostatic Conditions with Large Current Densities... 

To summarize the typical features of HNDR oscillators, they exhibit oscillatory behavior on a branch with a positive characteristic under galvanostatic as well as potentiostatic conditions when a sufficiently large series resistance is involved. At low current densities, the oscillations characteristically set in through a Hopf bifurcation they are predominantly destroyed by a saddle-loop bifurcation at high current densities and they coexist with a stable stationary state at much more anodic values and hence are associated with a hysteresis. 

In principal, the paired values of potential and current density should not depend on the experimental method used. However, under certain conditions, the polarization curves acquired under potential control are not identical to those acquired under current control. In particular, when the polarization curve exhibits a maximum or a plateau region, more information is contained in a potentiostatic measurement (Figure 4.4). On the other hand, the galvanostatic technique is of interest when the slope dUdE is steep, and a slight variation of potential leads to a large change in the measured current. Modern potentiostats usually include software that permits to select the desired mode of operation and to acquire and plot experimental data. 

---