Lithium Plating

Lithium plating is the deposition of metallic lithium on the surface of the graphite anode. This is one of the most significant degradation mechanisms:

  • reduces charge rate capability
  • consumes reversible lithium, thus reducing cell capacity
  • reduces anode porosity and hence reduces charge and discharge rate
  • lithium dendrite formation can lead to an internal short circuit and thermal runaway

Lu et al [1] show relaxation processes at different state-of-charge (SOC), wherein thermodynamically unstable graphite particles undergo a drastic intra-particle lithium redistribution and inter-particle lithium exchange at intermediate SOCs, whereas the electrode equilibrates much slower at low and high SOCs.

There are two basic types [2] of plating:

  1. Thermodynamic Plating where the negative electrode surface becoming fully lithiated, in which the Li has nowhere else to go.
  2. Kinetic Plating occurs during fast charging, where the high electrolyte potential increases the rate of the side reaction relative to the main intercalation reaction.

References

  1. Lu, X., Lagnoni, M., Bertei, A. et al. Multiscale dynamics of charging and plating in graphite electrodes coupling operando microscopy and phase-field modellingNat Commun 14, 5127 (2023). https://doi.org/10.1038/s41467-023-40574-6
  2. Jacqueline S. Edge, Simon O’Kane, Ryan Prosser, Niall D. Kirkaldy, Anisha N. Patel, Alastair Hales, Abir Ghosh, Weilong Ai, Jingyi Chen, Jiang Yang, Shen Li, Mei-Chin Pang, Laura Bravo Diaz, Anna Tomaszewska, M. Waseem Marzook, Karthik N. Radhakrishnan, Huizhi Wang, Yatish Patel, Billy Wu and Gregory J. Offer, Lithium ion battery degradation: what you need to know, Phys. Chem. Chem. Phys., 2021, 23, 8200