Interface Between Solid-State Electrolytes and Li-Metal Anodes: Issues, Materials, and Processing Routes

Abstract

Li metal, which has a high theoretical capacity and negative electrochemical potential, is regarded as the "holy grail" in Li-ion batteries. However, the flammable nature of liquid electrolyte leads to safety issues. Hence, the cooperation of solid-state electrolyte and Li-metal anode is demanded. However, the short cycle life induced by interfacial issues is the main challenge faced by their cooperation. In this review, dendrite and interfacial side reactions are comprehensively analyzed as the main interfacial problems. Meanwhile, the "state-of-the-art" interphase materials are summarized. The challenges faced by each kind of material are underscored. Moreover, different processing routes to fabricate artificial interphase are also investigated from an engineering perspective. The processing routes suitable for mass production are also underscored.

All‐Solid‐State Sodium Batteries with a Polyethylene Glycol Diacrylate–Na3Zr2Si2PO12 Composite Electrolyte

“…Sodium cells with a PEO‐based electrolyte could only be safely charged to a cut‐off voltage of 4.0 V [19b] . In such a case, we have to apply a second PAN‐based electrolyte layer to face the cathode when the Prussian blue was used for the operation of room‐temperature sodium cells [19b] . In this study, a single layer of PEGDA/NaClO 4 /SCN/Na 3 Zr 2 Si 2 PO 12 composite electrolyte can provide a sufficiently high upper‐limit electrochemical stability potential (4.4 V [vs Na + /Na]) for operating sodium cells with the Prussian blue cathode.…”

“…All‐solid‐state sodium batteries in this study were demonstrated with a Prussian‐blue (Na 2 MnFe(CN) 6 ) cathode. We have previously found that the PEO‐based electrolyte could sustain an upper‐limit electrochemical stability potential of ≈4.2 V (vs Na + /Na) [19b] . Sodium cells with a PEO‐based electrolyte could only be safely charged to a cut‐off voltage of 4.0 V [19b] .…”

“…We have previously found that the PEO‐based electrolyte could sustain an upper‐limit electrochemical stability potential of ≈4.2 V (vs Na + /Na) [19b] . Sodium cells with a PEO‐based electrolyte could only be safely charged to a cut‐off voltage of 4.0 V [19b] . In such a case, we have to apply a second PAN‐based electrolyte layer to face the cathode when the Prussian blue was used for the operation of room‐temperature sodium cells [19b] .…”

“…[ 18 ] As a result, the poor contact between the ceramic‐based solid electrolyte and the solid electrodes poses challenging interfacial problems in all‐solid‐state batteries. [ 19 ] Many strategies have been attempted to address the critical issue between the solid electrolyte and electrodes. [ 20 ] A polymer–ceramic compositing approach has been regarded as a promising one.…”

Impacts of vacancy-induced polarization and distortion on diffusion in solid electrolyte Li 3 OCl

“…All solid-state batteries with inorganic electrolytes are a promising new technology that can replace organic electrolytes in current Li-ion batteries. The solid inorganic electrolyte offers advances over the organic electrolyte in safety, durability, and potential volumetric and gravimetric energy density [1][2][3][4][5][6][7][8].…”