자료유형  

 학위논문

Control Number  

0017164868

International Standard Book Number  

9798346385622

Dewey Decimal Classification Number  

610

Main Entry-Personal Name  

Rose, Justin Andrew.

Publication, Distribution, etc. (Imprint  

[S.l.] : Stanford University., 2024

Publication, Distribution, etc. (Imprint  

Ann Arbor : ProQuest Dissertations & Theses, 2024

Physical Description  

107 p.

General Note  

Source: Dissertations Abstracts International, Volume: 86-05, Section: A.

General Note  

Advisor: Chueh, William.

Dissertation Note  

Thesis (Ph.D.)--Stanford University, 2024.

Summary, Etc.  

요약Deposition of metallic lithium on the negative electrode in lithium-ion batteries is a key degradation mode. Widely seen as a critical barrier to fast charging, this process must be understood to encourage widespread adoption of electric vehicles. It is associated with an array of detrimental effects on cell performance, including loss of lithium, loss of active material, and increased resistance, in addition to the safety hazards that cause battery fires and product recalls. To improve understanding and thereby offer improvements to battery performance, this thesis aims to study plating-induced degradation through the lens of intentional overcharge, enabling controlled experiments that are lacking in the literature. By dictating the conditions of lithium deposition, we are able to conduct experiments across a wide variety of length scales, creating a holistic view of the process and its effects on cell performance.First, in Chapter 1, a comprehensive overview of lithium plating is presented. The importance of plating to battery technology is highlighted, followed by a discussion of the conditions that lead to its occurrence. Later, the degradation modes linked to lithium plating are reviewed, and the evidence for its supposed effects are presented. While the effect of plating on cyclable lithium capacity is well understood, the evidence for other forms of degradation is lacking, and largely rely on experiments that convolute plating effects with other modes of fast charge degradation.In Chapter 2, we develop a specialized cell design and cycling protocol, enabling systematic study expected forms of plating-induced degradation. While we find that metal deposition does lead to high rates of lithium loss across most conditions, it can be surprisingly efficient with the right set of parameters. Furthermore, and most surprisingly, we see no evidence of plating-driven loss of active material or resistance rise, suggesting that the importance of these have been overstated in the literature. Instead, it is likely possible for a cell to survive isolated plating events without substantial degradation. The commonly postulated positive feedback loop, wherein small amounts of plating lead to inevitable future plating, appears to be inactive, at least in early stages of degradation.While electrochemical tests demonstrate that plating-driven degradation is less severe than expected at the cell scale, Chapter 3 examines the origins of this behavior through microscale morphology characterization. As a holistic picture of the deposition process cannot be achieved with top-down imaging alone, we employ cryo-microtomy to generate electrode cross-sections, enabling high-throughput characterization across the electrode depth. We show that lithium cyclability is largely based on its deposition morphology. Additionally, we find the surprising result that lithium plating does not occur in the pores of the graphite electrode, explaining its lack of influence on active material loss and resistance rise.Lastly, in Chapter 4 we conductnanoscale, operando characterization of the plating process with the use of atomic force microscopy. We first develop a graphite nanoplatelet model system for this purpose, though its strengths extend far beyond applications of this kind. Unexpectedly, it is found that lithium preferentially deposits beneath the surface of graphite particles, raising questions about the mechanism of deposition.

Subject Added Entry-Topical Term  

Tomography.

Subject Added Entry-Topical Term  

Electrolytes.

Subject Added Entry-Topical Term  

Graphite.

Subject Added Entry-Topical Term  

Electrodes.

Subject Added Entry-Topical Term  

Alternative energy.

Subject Added Entry-Topical Term  

Electric vehicles.

Subject Added Entry-Topical Term  

Microscopy.

Subject Added Entry-Topical Term  

Plating.

Subject Added Entry-Topical Term  

Causality.

Subject Added Entry-Topical Term  

Energy transition.

Subject Added Entry-Topical Term  

Lithium.

Subject Added Entry-Topical Term  

Medical imaging.

Subject Added Entry-Topical Term  

Transportation.

Added Entry-Corporate Name  

Stanford University.

Host Item Entry  

Dissertations Abstracts International. 86-05A.

Electronic Location and Access  

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Control Number  

joongbu:654326