Li/Garnet Interface Optimization: An Overview

Abstract

Solid-state lithium batteries can improve the safety and energy density of the present liquid-electrolyte-based lithium-ion batteries. To achieve this goal, both solid electrolyte and lithium anode technology are the keys. Lithium garnet is a promising electrolyte to enable the next generation solid-state lithium batteries due to its high ionic conductivity, good chemical, and electrochemical stability, and easiness to scale up. It is relatively stable against Li metal but the poor contact area and the presence of resistive impurity or decomposition layers at the interface interfere with fast charge transfer, thereby, spiking the interfacial resistance, overpotential, local current density, and the propensity for dendrite growth. In this Review, we first summarize the recent understanding of the interfacial problems at the Li/garnet interface from both computational and experimental viewpoints while seizing the opportunity to shed light on the chemical/electrochemical stability of garnet against Li metal anode. Also, we highlight various interface optimization strategies that have been demonstrated to be effective in improving the interface performance. We conclude this Review with a few suggestions as guides for future work.

Revealing Atomic-Scale Ionic Stability and Transport around Grain Boundaries of Garnet Li7La3Zr2O12 Solid Electrolyte

“…[3][4][5] Through the long-term development, a variety of high-performance solid electrolytes (SEs) has been successfully synthesized, whose ion conductivities are comparable with the traditional liquid electrolytes. [6][7][8][9] Among of them, the garnet-type Li7La3Zr2O12 (LLZO) as a superior solid electrolyte has attracted great interest, 8,10,11 thanks to its high conductivity (~ 10 -4 S/cm), wide electrochemical window (~ 6 eV) 12 . More attractively, LLZO shows good compatibility with the ultimate anode material, Li metal, to achieve an ASSB with a significantly high energy density.…”

Revealing Atomic‐Scale Ionic Stability and Transport around Grain Boundaries of Garnet Li7La3Zr2O12 Solid Electrolyte

“…[3][4][5] Through the long-term development, a variety of high-performance solid electrolytes (SEs) has been successfully synthesized, whose ion conductivities are comparable with the traditional liquid electrolytes. [6][7][8][9] Among of them, the garnet-type Li 7 La 3 Zr 2 O 12 (LLZO) as a superior solid electrolyte has attracted great interest, [8,10,11] owing to its high conductivity (≈10 -4 S cm −1 ), wide electrochemical window (≈6 eV). [12] More promisingly, LLZO shows a good compatibility with the ultimate anode material, Li metal, to achieve an ASSB with a significantly high energy density.…”

Dual interface design of Ga‐doped Li 7 La 3 Zr 2 O 12 /polymer composite electrolyte for solid‐state lithium batteries

“…Poor wettability and uneven Li/electrolyte contact can trigger Li dendrite formation at the interface. 37 Atomic layer deposition, sputtering deposition, molten Li infusion, and in situ polymerization have been adopted to improve compatibility at the anode/electrolyte interface. [37][38][39] However, these methods are usually sophisticated, costly, and time-consuming.…”

“…37 Atomic layer deposition, sputtering deposition, molten Li infusion, and in situ polymerization have been adopted to improve compatibility at the anode/electrolyte interface. [37][38][39] However, these methods are usually sophisticated, costly, and time-consuming. The insertion of an ionic liquid (IL) interlayer to join the Li metal and solid electrolyte has recently been proposed.…”