Advances in Materials Science and Engineering / 2014 / Article / Tab 1

Research Article

Novel Method for Floating Synthesizing Heavy Metal Particles as Flowing Anode of Zinc-Air Fuel Cell

Table 1

Causes of three types of overvoltage and their solutions.

CauseSolution

Activation overvoltageIf ions are absorbed on the electrode surface, the reaction mechanism by which O2 changed to OH ions will slow down. This leads to activation polarization and results in activation overvoltageElevate the temperature of a cell, as well as the reaction speed of three-phase boundaries

Concentration overvoltageBecause of poor gas diffusion, O2 supply in the reaction becomes too slow; as a result, O2 concentration becomes insufficient. This causes concentration polarization and results in concentration overvoltageElevate the flow speed of O2 at the anode and increase the O2 concentration

Ohmic overvoltageBecause of improper design, poor conductivity of electrolytes or impurities in the electrodes increasing resistance to current flow, ohmic polarization may occur, resulting in ohmic overvoltageUse electrode materials and electrolytes with higher conductivity