Plan-View <i>Operando</i> Video Microscopy of Li Metal Anodes: Identifying the Coupled Relationships among Nucleation, Morphology, and Reversibility

Capacity retention in lithium metal batteries needs to be improved if they are to be commercially viable, the low cycling stability and Li corrosion during storage of lithium metal batteries being even more problematic when there is no excess lithium in the cell. Herein, we develop in situ NMR metrology to study “anode-free” lithium metal batteries where lithium is plated directly onto a bare copper current collector from a LiFePO4 cathode. The methodology allows inactive or “dead lithium” formation during plating and stripping of lithium in a full-cell lithium metal battery to be tracked: dead lithium and SEI formation can be quantified by NMR and their relative rates of formation are here compared in carbonate and ether-electrolytes. Little-to-no dead Li was observed when FEC is used as an additive. The bulk magnetic susceptibility effects arising from the paramagnetic lithium metal were used to distinguish between different surface coverages of lithium deposits. The amount of lithium metal was monitored during rest periods, and lithium metal dissolution (corrosion) was observed in all electrolytes, even during the periods when the battery is not in use, i.e., when no current is flowing, demonstrating that dissolution of lithium remains a critical issue for lithium metal batteries. The high rate of corrosion is attributed to SEI formation on both lithium metal and copper (and Cu+, Cu2+ reduction). Strategies to mitigate the corrosion are explored, the work demonstrating that both polymer coatings and the modification of the copper surface chemistry help to stabilize the lithium metal surface.

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“… 7 , 8 Dead Li corresponds to Li that no longer has an electronic contact with the current collector. 8 − 11 …”

Section: Introductionmentioning

confidence: 99%

Noninvasive In Situ NMR Study of “Dead Lithium” Formation and Lithium Corrosion in Full-Cell Lithium Metal Batteries

et al. 2020

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“…While the voltage profiles in Figure 8 show the ideal scenario, the profiles in practice may not look as smooth. In a symmetric cell, the half cycle begins with the nucleation and since the nucleation is always a kinetically slow process, it occurs as a peak with shallow slope in the beginning of the voltage profile [40,41] . As soon as the nucleation has begun at a fairly large number of sites, the deposition begins, the kinetics transition to a faster phase, and the profile tends to become flatter.…”

Section: Galvanostatic Cycling To Measure Overpotentialsmentioning

confidence: 99%

Electrochemical Methods and Protocols for Characterization of Ceramic and Polymer Electrolytes for Rechargeable Batteries

Deivanayagam

Shahbazian‐Yassar

2021

Batteries & Supercaps

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Solid‐state lithium batteries are widely believed to be the most feasible next‐generation battery technology. New material candidates for solid electrolytes are typically screened using meticulous characterization methods and ranked using metrics such as ionic conductivity, transference number, decomposition voltage, and deposition/stripping overpotential. The determination of these metrics requires the use of a variety of electrochemical experiments, the details of which are scattered across existing literature and could be time‐consuming for a beginner to locate. Here, we present a comprehensive overview of the electrochemical concepts, methods, and protocols adopted to characterize the polymer and ceramic electrolyte candidates for rechargeable batteries. This work facilitates the understanding of the key parameters involved in solid‐state electrolyte characterization and in interpreting their data.

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“…A substrate with preferred nucleation can decrease the formation of dead Li and improve the charge‐discharge coulombic efficiency. [ 13 ]…”

Section: Introductionmentioning

confidence: 99%

Mechanisms of the Planar Growth of Lithium Metal Enabled by the 2D Lattice Confinement from a Ti₃C₂T_x MXene Intermediate Layer

Yang

Zhao

Lian

et al. 2021

Adv Funct Materials

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The propensity of Li to form irregular and nonplanar electrodeposits has become a fundamental barrier for fabricating Li metal batteries. Here, a planar, dendrite‐free Li metal growth on 2D Ti3C2Tx MXene is reported. Ab initio calculations suggest that Li forms a hexagonal close‐packed (hcp) layer on the surface of Ti3C2Tx via ionic bonding and the lattice confinement. The ionic bonding weakens gradually after a few monolayers, resulting in a nanometers‐thin transition region of hcp‐Li. Above this transition region, the deposition is dominated by plating of body‐centered cubic (bcc) Li via metallic bonding. Formation of a dense and planar Li metal anode with preferential growth along the (110) facet is explained by the lattice matching between Ti3C2Tx and hcp‐Li and then with bcc‐Li, as well as preferred thermodynamic factors including the large dendrite formation energy and small migration barrier for Li. The prepared Li metal anode shows stable cycling in a wide current density range from 0.5 to 10.0 mA cm–2. The LiFePO4‖Li full cell fabricated with this Li metal anode exhibits only 9.5% capacity fading after 500 charge–discharge cycles at 1 C rate.

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Plan-View Operando Video Microscopy of Li Metal Anodes: Identifying the Coupled Relationships among Nucleation, Morphology, and Reversibility

Cited by 97 publications

References 50 publications

Noninvasive In Situ NMR Study of “Dead Lithium” Formation and Lithium Corrosion in Full-Cell Lithium Metal Batteries

Noninvasive In Situ NMR Study of “Dead Lithium” Formation and Lithium Corrosion in Full-Cell Lithium Metal Batteries

Electrochemical Methods and Protocols for Characterization of Ceramic and Polymer Electrolytes for Rechargeable Batteries

Mechanisms of the Planar Growth of Lithium Metal Enabled by the 2D Lattice Confinement from a Ti₃C₂T_x MXene Intermediate Layer

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Plan-View Operando Video Microscopy of Li Metal Anodes: Identifying the Coupled Relationships among Nucleation, Morphology, and Reversibility

Cited by 97 publications

References 50 publications

Noninvasive In Situ NMR Study of “Dead Lithium” Formation and Lithium Corrosion in Full-Cell Lithium Metal Batteries

Noninvasive In Situ NMR Study of “Dead Lithium” Formation and Lithium Corrosion in Full-Cell Lithium Metal Batteries

Electrochemical Methods and Protocols for Characterization of Ceramic and Polymer Electrolytes for Rechargeable Batteries

Mechanisms of the Planar Growth of Lithium Metal Enabled by the 2D Lattice Confinement from a Ti3C2Tx MXene Intermediate Layer

Contact Info

Product

Resources

About

Mechanisms of the Planar Growth of Lithium Metal Enabled by the 2D Lattice Confinement from a Ti₃C₂T_x MXene Intermediate Layer