Exploring interfacial stability of solid-state electrolytes at the lithium-metal anode surface

AbstractThe interfacial instability of the lithium-metal anode and shuttling of lithium polysulfides in lithium-sulfur (Li-S) batteries hinder the commercial application. Herein, we report a bifunctional electrolyte additive, i.e., 1,3,5-benzenetrithiol (BTT), which is used to construct solid-electrolyte interfaces (SEIs) on both electrodes from in situ organothiol transformation. BTT reacts with lithium metal to form lithium 1,3,5-benzenetrithiolate depositing on the anode surface, enabling reversible lithium deposition/stripping. BTT also reacts with sulfur to form an oligomer/polymer SEI covering the cathode surface, reducing the dissolution and shuttling of lithium polysulfides. The Li–S cell with BTT delivers a specific discharge capacity of 1,239 mAh g−1 (based on sulfur), and high cycling stability of over 300 cycles at 1C rate. A Li–S pouch cell with BTT is also evaluated to prove the concept. This study constructs an ingenious interface reaction based on bond chemistry, aiming to solve the inherent problems of Li–S batteries.

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The DFT-ReaxFF Hybrid Reactive Dynamics Method with Application to the Reductive Decomposition Reaction of the TFSI and DOL Electrolyte at a Lithium–Metal Anode Surface

The Journal of Physical Chemistry Letters ◽

10.1021/acs.jpclett.0c03720 ◽

2021 ◽

Vol 12 (4) ◽

pp. 1300-1306

Author(s):

Yue Liu ◽

Peiping Yu ◽

Yu Wu ◽

Hao Yang ◽

Miao Xie ◽

...

Keyword(s):

Decomposition Reaction ◽

Anode Surface ◽

Lithium Metal ◽

Metal Anode ◽

Reductive Decomposition ◽

Lithium Metal Anode ◽

Reactive Dynamics ◽

Dynamics Method

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Creep and Anisotropy of Free-Standing Lithium Metal Foils in an Industrial Dry Room

Journal of Electrochemical Energy Conversion and Storage ◽

10.1115/1.4052043 ◽

2021 ◽

pp. 1-32

Author(s):

Lara Dienemann ◽

Anil Saigal ◽

Michael A Zimmerman

Keyword(s):

Mechanical Properties ◽

Solid State ◽

High Volume ◽

Dominant Mode ◽

Lithium Metal ◽

Free Standing ◽

Metal Anode ◽

Lithium Metal Batteries ◽

Lithium Metal Anode ◽

Solid State Batteries

Abstract Commercialization of energy-dense lithium metal batteries relies on stable and uniform plating and stripping on the lithium metal anode. In electrochemical-mechanical modeling of solid-state batteries, there is a lack of consideration of specific mechanical properties of battery-grade lithium metal. Defining these characteristics is crucial for understanding how lithium ions plate on the lithium metal anode, how plating and stripping affect deformation of the anode and its interfacing material, and whether dendrites are suppressed. Recent experiments show that the dominant mode of deformation of lithium metal is creep. This study measures the time and temperature dependent mechanics of two thicknesses of commercial lithium anodes inside an industrial dry room, where battery cells are manufactured at high volume. Furthermore, a directional study examines the anisotropic microstructure of 100 µm thick lithium anodes and its effect on bulk creep mechanics. It is shown that these lithium anodes undergo plastic creep as soon as a coin cell is manufactured at a pressure of 0.30 MPa, and achieving thinner lithium foils, a critical goal for solid-state lithium batteries, is correlated to anisotropy in both lithium's microstructure and mechanical properties.

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