A recent study published in Nature Communications explores the mechanisms behind stable lithium plating and stripping in anode-less (AL) solid-state (SS) lithium metal batteries (LMBs) with metal interlayers. Researchers conducted multiple operando and post-mortem analyses to understand the microstructural evolution and electrochemical performance of AL-SS-LMBs incorporating gold (Au), silver (Ag), zinc (Zn), and copper (Cu) interlayers on a garnet-type solid electrolyte, Li6.5La3Zr1.5Ta0.5O12 (LLZO).
Image Credit: concept w/Shutterstock.com
Background
Solid-state lithium metal batteries (SS-LMBs) exhibit higher energy density than conventional lithium-ion batteries. However, the use of lithium metal as an anode in large-scale manufacturing remains complex due to handling challenges and associated costs.
Anode-less SS-LMBs (AL-SS-LMBs) eliminate direct lithium metal handling by relying solely on lithium sourced from the cathode. Metal interlayers are integrated with the solid electrolyte to stabilize the interface between the electrolyte and anode, impacting battery performance.
The metal interlayers in AL-SS-LMBs function as buffer layers by forming lithium alloys, which influence the lithium plating and stripping process. This study evaluates the effect of different metal interlayers on interfacial stability in AL-SS-LMBs.
Methods
Commercially procured LLZO pellets (500 μm thick, 14 mm in diameter) were used to fabricate three types of cells: operando, half, and hybrid full-cells. The operando and half-cells (metal|LLZO|Li cells) featured a lithium metal anode and a copper foil cathode, with sputtered thin metal layers (silver, zinc, gold, or copper) used as working electrodes.
Hybrid full-cells incorporated an anode similar to that in the operando half-cell, with metal interlayers deposited at the solid electrolyte/current collector interface. The cathode consisted of LiNi1/3Co1/3Mn1/3O2 (NCM111) coated on aluminum, with a catholyte composed of lithium bis(fluorosulfonyl)imide (LiFSI) in N-methyl-N-propyl pyrrolidinium bis(fluorosulfonyl)imide (Pyr13FSI)). The charge-discharge characteristics were analyzed at 25 °C using a battery cycler.
Structural evolution was examined using operando scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). Post-mortem analysis included SEM and transmission electron microscopy (TEM) of cross-sectional samples. Nanoscale structural insights were obtained through scanning transmission electron microscopy with electron energy loss spectroscopy (STEM-EELS). Density functional theory calculations using the Vienna ab initio simulation package provided theoretical support.
Results and Discussion
Operando and post-mortem analyses revealed morphological, chemical, and microstructural changes in lithium deposits in AL-SS-LMBs, highlighting correlations between lithium-metal alloying, structural evolution, and electrochemical performance.
Among the examined interlayers, silver demonstrated the highest interfacial stability due to a distinct phase transition during lithium-silver alloying. The silver-dissolved lithium plating process reduced dendritic growth, contributing to stable battery operation.
In contrast, zinc, gold, and copper interlayers were less effective in suppressing dendritic growth. Their inability to form lithium-rich alloys (gold and zinc) or their low lithium solubility (copper) resulted in non-uniform lithium plating at the solid electrolyte-metal interlayer interface. This led to dead lithium accumulation and loss of contact at the interface, adversely affecting battery performance.
With the silver interlayer, lithium plating proceeded through the lithiated silver layer rather than at the interface, mitigating dead lithium formation and preventing current collector delamination. Lithium deposits formed as irregular clusters with large contact areas on the silver interlayer surface rather than as high-aspect-ratio dendrites.
This behavior was attributed to the high chemical reactivity between lithium and silver. This enabled silver dissolution into the lithium layer, forming a stable solid solution that further inhibited dendrite growth.
These findings provide insights into material selection and interface design for AL-SS-LMBs. Addressing interfacial instability issues is essential for advancing the practical application of solid-state lithium metal batteries in high-energy-density storage systems.
Journal Reference
Ko, D.-S., et al. (2025). Mechanism of stable lithium plating and stripping in a metal-interlayer-inserted anode-less solid-state lithium metal battery. Nature Communications. DOI: 10.1038/s41467-025-55821-1, https://www.nature.com/articles/s41467-025-55821-1
Disclaimer: The views expressed here are those of the author expressed in their private capacity and do not necessarily represent the views of AZoM.com Limited T/A AZoNetwork the owner and operator of this website. This disclaimer forms part of the Terms and conditions of use of this website.