Research on the thermo-electrochemical behavior during the electrodeposition process of lithium metal battery

Lithium metal batteries (LMBs) are promising renewable energy storage device with higher energy density. During charging/discharging, the electrodeposition or dendrite growth on surface of Li electrode and temperature influence thermo-electrochemical behaviors in LMBs greatly. Coupling electrochemical reaction kinetic equations and thermal relations in electrode, as well as diffusion migrating equations of Li+ ion in electrolyte is employed to investigate the effects of temperature, charging current density, volume fraction of active solid and Li concentration in positive electrode, as well as salt concentration in electrolyte on the entropy production relating to power consumption and Joule heat, as well as cell voltage and overpotential in positive electrode and negative electrode with protrusion surface during charging. More polarization reactions together with larger heat generation take place, and cause more entropy generation in area of protrusion. The voltage efficiency is defined to evaluate thermo-electrochemical behaviors in LMBs, and the higher voltage efficiency occurs with the decrease in charging current density. The 93.6% voltage efficiency can be obtained in the case with solid-phase volume fraction of 0.518 in positive electrode under charging current density of 43.608A/m2. All results from investigation will be beneficial to obtain better thermo-electrochemical behavior in Li metal batteries.