Journal
ENERGY STORAGE MATERIALS
Volume 48, Issue -, Pages 475-486Publisher
ELSEVIER
DOI: 10.1016/j.ensm.2022.03.037
Keywords
Reaction distribution; Modeling; Four-electrode measurements; Li-ion batteries; Li+ concentration waves
Funding
- China Scholarship Council
Ask authors/readers for more resources
Specific Li+ concentration waves can occur in the electrolyte of graphite-based porous electrode/Li cells, which are influenced by both thermodynamics and kinetics.
Electrolyte solutions function as ionic conductors in Li-ion batteries and inevitably induce concentration gra-dients during battery operation. It is shown that in addition to these concentration gradients, very specific Li + concentration waves in the electrolyte are formed in graphite-based porous electrode/Li cells. This phenomenon has been investigated by both simulations and experiments. From the simulations, it has been concluded that the occurring Li + concentration waves in the electrolyte vary with position and time. Such waves originate from the fluctuations of the reaction distribution inside the porous electrode and depend on both the thermodynam-ics (open-circuit voltage, OCV) and kinetics (charge transfer reaction heterogeneity). Li + concentration waves occurring inside the separator region are directly related to the battery output voltage at low current applica-tions. A four-electrode device is used to validate the electrolyte concentration waves experimentally. The electric potential differences between the reference electrodes and counter electrode show regular fluctuations, demon-strating the existence of concentration waves in the electrolyte. The simultaneous appearance of the fluctuations in the potential differences and the transitions from plateaus to slopes in the battery output voltage illustrates the dependency of Li + concentration waves on the thermodynamics and kinetics of the electrochemical reactions.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available