Elucidating Zn and Mg Electrodeposition Mechanisms in Nonaqueous Electrolytes for Next-Generation Metal Batteries

From a combination of experimental measurements and simulation data, we suggest that Zn follows a simple two-electron reduction process (E mechanism). Mg electrodeposits by a more complicated pathway that involves a chemical step prior to the charge transfer step. This mechanism is known as the chemical-electrochemical (CE) process

Scientific Achievement

The development of nonaqeuous electrolytes enabling reversible and efficient deposition/stripping of multivalent metals has been hindered because of the complexity of electrolyte properties and behaviors. Different cations exhibit different deposition efficacy. Our research explores Zn and Mg deposition mechanisms and explains differences between the two cations.

Significance and Impact

Our research shows that Mg and Zn electrodeposit by two fundamentally different mechanisms.  Mg requires a chemical step in addition to an electron transfer step, while Zn just requires an electron transfer step.  This result suggests that facile Mg deposition may be reached at higher temperatures whereas Zn electrodeposition may be enhanced by increasing electron-transfer rate constant, likely through additives.

Research Details

  • CVs of Zn deposition at a ultramicroelectrode (UME) exhibit an independent relationship between current density and scan rate indicating a simple two-electron reduction mechanism.
  • CVs of Mg deposition at a UME show an inverse dependence between scan rate and current density suggesting a more complicated chemical-electrochemical process.
  • By coupling electrochemistry with COMSOL simulation, our study provides kinetic parameters and insights central to the Zn and Mg electrodeposition/dissolution processes.


Download this highlight

Latest Updates

See All