Prolonging the cycling lifetime of lithium metal batteries with a monolithic and inorganic-rich solid electrolyte interphase

Abstract

An efficient solid electrolyte interphase (SEI) on lithium (Li) metal anode is crucial to suppressing Li dendrite. Herein, a methoxide electrolyte additive, i.e., potassium methoxide, is revealed to induce preferential...

High-flux charge transfer layer confers a solid electrolyte interphase with uniform and rich LiF for stable lithium metal batteries

“…The uncontrollable formation of this SEI appears to lower the Li + diffusion kinetics and creates uneven Li deposition, 14 which will then decrease the coulombic efficiency and cycle life. 15 Thus, it is critically essential to engineer a stable and controllable SEI layer for regulating the Li stripping/deposition behaviors to achieve high-performance Li metal batteries.…”

Constructing an inorganic-rich solid electrolyte interphase by adjusting electrolyte additives for stable Li metal anodes

“…10 Compared with an organic-rich SEI layer, an SEI with abundant inorganic Li compounds (such as LiF, Li 2 CO 3 , and Li 2 O) displays suitable Li + ionic conductivity, lithiophobicity, and high interfacial energy, which can promote Li transverse diffusion along the SEI/Li interface. 11,12 In addition, the inorganic matter with higher Young's modulus also has strong mechanical strength to better inhibit dendritic growth. 13 Therefore, a high-quality SEI is essential for exceptional Li metal batteries.…”

Additive-Driven Nanoscale Architecture of Solid Electrolyte Interphase Revealed by Cryogenic Transmission Electron Microscopy

“…22−24 These electrolytes can mainly induce a decomposition of anions to form beneficial SEI on the basis of a change in a solvation structure. 25,26 The anion-derived SEI includes abundant inorganic components that exhibit superior chemo-mechanical stability and ionic conductivity compared to organic components produced from the decomposition of solvent. 27−29 Therefore, the coutilization of those two approaches can be considered as an efficient electrolyte engineering to form a desired SEI with enhanced ionic conductivity and mechanical stability.…”

“…In particular, using additives is one of the most effective and economic methods for the improvement of performance because they modify the electrode/electrolyte interphase with only a relatively small amount. , It has been known that additives can form desired inorganic components (LiF, Li 3 N, etc.) within the SEI by the preferential reduction based on their electronic structures. , These reduction products are ideally characterized by high ionic conductivity, facilitating Li ion transport across the SEI, and high mechanical stability to accommodate the expansion of the electrode. − Recently, another approach in electrolyte engineering has received attention: increasing salt-to-solvent ratio, such as high concentration electrolytes (HCEs) and localized high-concentration electrolytes (LHCEs). − These electrolytes can mainly induce a decomposition of anions to form beneficial SEI on the basis of a change in a solvation structure. , The anion-derived SEI includes abundant inorganic components that exhibit superior chemo-mechanical stability and ionic conductivity compared to organic components produced from the decomposition of solvent. − Therefore, the coutilization of those two approaches can be considered as an efficient electrolyte engineering to form a desired SEI with enhanced ionic conductivity and mechanical stability. However, it is poorly understood how the complicated electrolyte composition affects the formation process of SEI and the resulting structures of it.…”

“…Generally, the influence of additives has been investigated by electrochemical measurements and micrometer-scale analysis such as X-ray photoelectron spectroscopy (XPS). ,,− These approaches can effectively provide information regarding modified physicochemical properties and chemical bondings in SEI. However, there are other crucial factors that determine the Li ion transportation within SEI, including crystallinity and distribution of inorganic components and the type of SEI structure. ,, They can only be understood by direct observation of the exact nanoscale structure of the SEI formed on the surface of Li metal. In this respect, cryogenic transmission electron microscopy (cryo-TEM), which utilizes extremely low temperatures of below −170 °C for noninvasive imaging of sensitive Li and SEI, is the powerful tool for studying the structure of SEI and Li. − …”