Bifunctional Interphase-Enabled Li₁₀GeP₂S₁₂ Electrolytes for Lithium–Sulfur Battery

Abstract

Li 10 GeP 2 S 12 (LGPS) has a high ionic conductivity and compatibility with sulfur cathodes; however, the instability of LGPS against Li and Li dendrite growth still remains unsolved. Here, we solved these two challenges by forming a lithiophilic−lithiophobic gradient interlayer interphase layer between Li and LGPS through the sequential reduction of salts and solvent in Mg(TFSI) 2 -LiTFSI-DME liquid electrolyte at the LGPS/Li interface (TFSI = bis(trifluoromethanesulfonyl)imide; DME = dimethoxyethane). Mg(TFSI) 2 -LiTFSI is first reduced, forming a lithiophilic Li x Mg alloy-rich layer on the lithium surface and a lithiophobic LiF-rich layer on top of Li x Mg due to the lithiophobicity difference. The later reduced DME solvent forms a flexible organic polymer between the LiF-rich layer and LGPS. After evaporation of DME solvent, the Li/LGPS/Ni-Li 2 S-LiTiS 2 all-solid-state battery shows a reversible capacity of 699.7 mAh g −1 (1.07 mAh cm −2 ) based on the mass of Ni-Li 2 S-LiTiS 2 at 100 mA g −1 (0.26 mA cm −2 ). The rational design of a solid electrolyte interface between a Li anode and LGPS electrolyte opens a new opportunity to develop high-performance all-solid-state lithium batteries.

Interfacial Design for a 4.6 V High‐Voltage Single‐Crystalline LiCoO2 Cathode

“…Element doping, surface coating, and electrolyte design are the most effective strategies. [ 15–25 ] Element doping notably tunes the basic physical properties of materials, while the doping strategies introduced some inactive elements into the cathode, lowered the specific capacity and energy density of the cathode, which canceled the advantages of increased cutoff voltage. Surface coating can protect the electrode surface, by optimizing the coating surficial structure, reducing the activity of electrolyte, and suppressing the transition‐metal‐ion dissolution, numerous surface coating strategies have been put forward in the past several years.…”

Air Stability and Interfacial Compatibility of Sulfide Solid Electrolytes for Solid‐State Lithium Batteries: Advances and Perspectives

“…Copyright 2020, American Chemical Society. c) Illustration of in situ formation of the LixMg/LiF/polymer (lithiophilic‐lithiophobic) solid electrolyte interphase between Li and LGPS [101] . Copyright 2021, American Chemical Society.…”

Electrochemical Impedance Spectroscopy of PEO-LATP Model Multilayers: Ionic Charge Transport and Transfer

“…Many solutions to prevent dendrite nucleation and growth have been proposed, such as using a nonflammable solid separator 4 or forming a stable solid electrolyte interphase (SEI) at the Li/electrolyte interface. 5 − 7 One strategy aims then at developing all-solid-state Li metal batteries, 8 , 9 which could mitigate dendrite growth and increase both battery safety and cycle life.…”