Exploration of Metal Alloys as Zero‐Resistance Interfacial Modification Layers for Garnet‐Type Solid Electrolytes

Abstract

A solid-state battery with a lithium-metal anode and a garnet-type solid electrolyte has been widely regarded as one of the most promising solutions to boost the safety and energy density of current lithium-ion batteries. However, lithiophobic property of garnet-type solid electrolytes hinders the establishment of a good physical contact with lithium metal, bringing about a large lithium/garnet interfacial resistance that has remained as the greatest issue facing their practical application in solid-state batteries. Herein, a meltquenching approach is developed by which varieties of interfacial modification layers based on metal alloys can be coated uniformly on the surface of the garnet. It is demonstrated that with an ultrathin, lithiophilic AgSn 0.6 Bi 0.4 O x coating the interfacial resistance can be eliminated, and a dendrite-free lithium plating and stripping on the lithium/garnet interface can be achieved at a high current density of 20 mA cm −2 . The results reveal that the uniform coating on the garnet surface and the facile lithium diffusion through the coating layer are two major reasons for the excellent electrochemical performances. The all-solid-state full cell consisting of the surface modified garnettype solid electrolyte with a LiNi 0.8 Mn 0.1 Co 0.1 O 2 cathode and a lithium-metal anode maintains 86% of its initial capacity after 1000 stable cycles at 1 C.

Interfacial engineering for high‐performance garnet‐based solid‐state lithium batteries

“…The modified LLZGO achieved a high critical current density (CCD) of 12.05 mA cm −2 at room temperature and stable cycling for 2000 h at a current density of 2.0 mA cm −2 . Additionally, taking into account the advantages of alloying in promoting the transport of lithium ions at the interface, Cui et al 106 successfully prepared different metal alloy modifying layers on the surface of LLZTO using rapid quenching techniques (Figure 3D). Through extensive comparisons, they found that the AgSn 0.6 Bi 0.4 O x modifying layer exhibited negligible interface impedance, with a high limit current density of 20.0 mA cm −2 at 60 • C, providing a new research direction for the preparation of high-entropy alloy interfaces.…”

“…(D) Rapid sintering method for fabricating high‐entropy alloy interfaces. Reproduced with permission 106 . Copyright 2023, Wiley‐VCH.…”

Recent Advances in Developing High-Performance Solid-State Lithium Batteries: Interface Engineering

“…(c) Diagram of the melt-quenching procedure used to create the alloy-coated LLZTO electrolyte. This panel was reproduced with permission from ref . Copyright 2023 Wiley-VCH.…”

“…This technique has the potential to revolutionize Li metal engineering and be used in manufacturing Li metal batteries by the industrial system. In another investigation, Cui et al 165 established a metal quenching technique for evenly coating various interfacial modification layers based on metal alloys on the surface of garnet, illustrated in Figure 13c. They demonstrated that the interfacial resistance between lithium and garnet might be lowered at high current densities using a coating of ultrathin lithiophilic AgSn 0.6 Bi 0.4 O x .…”

Recent Progress on Nanomodification Applied in Anodes of Rechargeable Li Metal Batteries

“…Garnet-type solid electrolytes have gained significant attention in recent years due to their stability. They exhibit good chemical compatibility with lithium metal and possess high ionic conductivity, which leads to enhanced safety and energy density in lithium ion batteries. , To address the issue of dendrite growth, lithium garnet (Li 6.4 La 3 Zr 1.4 Ta 0.6 O 12 , LLZTO) particles and lithium salt-free poly­(ethylene oxide) (PEO) were used to create a composite film by Zhang et al Remarkably, this solid electrolyte film demonstrated no dendrite growth even after 700 h of cycling. The nanoscale lithium ion conducting particles effectively improved electrical conductivity, while the insulating PEO in the PEO:LLZTO film electrolyte inhibited dendrite growth due to current limitations.…”