Materials Research Activities

Polarization:: (Electrochemistry

Polarization:: (Electrochemistry.) Polarization refers to an effect reducing the performance of batteries. This effect is a displacement of electrode potential from the equilibrium value. There are two types of polarization: activation and concentration. All electrochemical reactions occur in a series of steps at the interface between electrode and electrolyte. Activation polarization refers to the condition wherein the reaction rate is determined by the slowest step. The term “activation” is used because an activation energy barrier is associated with this slowest, rate-limiting step. The second type, concentration polarization, occurs when the reaction rate is limited by diffusion in the solution (in conventional batteries the electrolyte is a solution).