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Abstract The commercialization of high‐energy Li‐metal batteries is impeded by Li dendrites formed during electrochemical cycling and the safety hazards it causes. Here, a novel porous copper current collector that can effectively mitigate the dendritic growth of Li is reported. This porous Cu foil is fabricated via a simple two‐step electrochemical process, where Cu‐Zn alloy is electrodeposited on commercial copper foil and then Zn is electrochemically dissolved to form a 3D porous structure of Cu. The 3D porous Cu layers on average have a thickness of ≈14 um and porosity of ≈72%. This current collector can effectively suppress Li dendrites in cells cycled with a high areal capacity of 10 mAh cm−2and under a high current density of 10 mA cm−2. This electrochemical fabrication method is facile and scalable for mass production. Results of advanced in situ synchrotron X‐ray diffraction reveal the phase evolution of the electrochemical deposition and dealloying processes.
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Operando Electrochemical Kinetics in Particulate Porous Electrodes by Quantifying the Mesoscale Spatiotemporal Heterogeneities
Abstract Electrochemical energy systems rely on particulate porous electrodes to store or convert energies. While the three‐dimensional (3D) porous structures are introduced to maximize the interfacial area for better overall performance of the system, spatiotemporal heterogeneities arising from materials thermodynamics are localizing the charge transfer processes onto a limited portion of the available interfaces. Here, a simple but precise method is demonstrated to directly track and analyze theoperando(i.e., local and working) interfaces on the mesoscale in a practical graphite porous electrode to obtain the true local current density, which turns out to be two orders of magnitude higher than the globally averaged current density adopted by existing studies. The results shed light on the long‐standing discrepancies in kinetics parameters derived from electroanalytical measurements and from first principle predictions. Contradictory to prevailing beliefs, the electrochemical dynamics are not controlled by the solid‐state diffusion process once the spatiotemporal reaction heterogeneities emerge.
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- Award ID(s):
- 2044932
- PAR ID:
- 10452544
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Energy Materials
- Volume:
- 11
- Issue:
- 12
- ISSN:
- 1614-6832
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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