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Li dendrite formed in Li metal batteries can be categorized into two different types. One is the detrimental Li dendrite that heads towards the separator with a potential to short cell. The other is the ill-defined fibrous Li formed within bulk Li metal. The detrimental Li dendrite may cause cell short, while the other dendrites, covered by SEI, mainly increase cell impedance and terminate the cell operation, most often, before any “short” really happens. Without decoupling these two different Li dendrites, it is hard to develop any effective approach to realize both stable and safe Li metal batteries. Herein, a straightforward approach is proposed to induce the growth of detrimental dendritic Li so the cells are “shorted” frequently and consistently. Based on this new protocol, various electrolytes are revisited and the SEI derived are compared and quantified, providing new insights for addressing the challenges in rechargeable Li metal battery technologies.
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Nondestructively Visualizing and Understanding the Mechano‐Electro‐chemical Origins of “Soft Short” and “Creeping” in All‐Solid‐State Batteries
Abstract All‐solid‐state Li‐metal batteries (ASLMBs) represent a significant breakthrough in the quest to overcome limitations associated with traditional Li‐ion batteries, particularly in energy density and safety aspects. However, widespread implementation is stymied due to a lack of profound understanding of the complex mechano‐electro‐chemical behavior of Li metal in the ASLMBs. Herein, operando neutron imaging and X‐ray computed tomography (XCT) are leveraged to nondestructively visualize Li behaviors within ASLMBs. This approach offers real‐time observations of Li evolutions, both pre‐ and post‐ occurrence of a “soft short”. The coordination of 2D neutron radiography and 3D neutron tomography enables charting of the terrain of Li metal deformation operando. Concurrently, XCT offers a 3D insight into the internal structure of the battery following a “soft short”. Despite the manifestation of a “soft short”, the persistence of Faradaic processes is observed. To study the elusive “soft short” , phase field modeling is coupled with electrochemistry and solid mechanics theory. The research unravels how external pressure curbs dendrite growth, potentially leading to dendrite fractures and thus uncovering the origins of both “soft” and “hard” shorts in ASLMBs. Furthermore, by harnessing finite element modeling, it dive deeper into the mechanical deformation and the fluidity of Li metal.
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- PAR ID:
- 10482776
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Functional Materials
- Volume:
- 33
- Issue:
- 52
- ISSN:
- 1616-301X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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