<p>The widespread commercialization of electric vehicles
is currently hindered by their inability to compete with conventional
gasoline-powered vehicles in terms of refueling time. The main barrier to
achieving fast charge of lithium-ion batteries is the plating of metallic
lithium on the surface of the graphite negative electrode, which is known to
occur most prevalently at high C-rates, low temperatures, and high states of
charge (SOC). While it is accepted that the lithium plating process is largely
reversible, the factors affecting the reversibility of lithium plating have not
been thoroughly investigated. This work seeks to determine the most influential
factors affecting the reversibility of lithium plating in order to devise
strategies to mitigate long-term damage to the cell if lithium plating has been
detected. It was determined that the temperature during the rest phase
following plating has the most significant influence on plating reversibility,
with cells undergoing rest at 30 ℃ exhibiting nearly twice the Coulombic
inefficiency of cells undergoing rest at 0 ℃. Additionally, a novel technique
was developed to observe the relaxation processes directly in a graphite
electrode just after lithium plating has occurred. The occurrence of
electrochemical stripping and the dissolution of overshooting phases in
graphite were verified through direct <i>in-situ</i>
observation. A two-part model is presented to describe the progression of the
relaxation processes in graphite after lithium plating occurs under high rate operation.</p>
| Identifer | oai:union.ndltd.org:purdue.edu/oai:figshare.com:article/11323952 |
| Date | 06 December 2019 |
| Creators | Tanay Adhikary (8086517) |
| Source Sets | Purdue University |
| Detected Language | English |
| Type | Text, Thesis |
| Rights | CC BY 4.0 |
| Relation | https://figshare.com/articles/Operando_Analysis_of_Lithium_Plating_in_Lithium-Ion_Cells/11323952 |
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