Improved Interfaces of Mechanically Modified Lithium Electrodes with Solid Polymer Electrolytes

Abstract

The combination of mechanically modified lithium electrodes and solid polymer electrolytes (SPEs) is investigated. So far, modified lithium electrodes, e.g., via structuring, are successfully used in combination with liquid electrolytes like ionic liquid‐based and organic solvent‐based ones. Specific SPEs have proven to be well compatible with lithium metal, even better than with liquid electrolytes. Nevertheless, the interface between lithium and SPEs is a complex issue. In this work, the challenge of the adequate wetting of the lithium electrode surface, especially a structured lithium surface, with a solid polymer is faced to successfully improve the interfacial properties and thus the performance, by a new method for the coating of such electrodes. The wetting of the micropatterned lithium surface by the SPE and the directed lithium electrodeposition in the patterns are verified by scanning electron microscopy analysis. The electrochemical properties of Li|SPE assemblies are investigated on the basis of constant current cycling and impedance experiments.

In Situ Electrolyte Gelation to Prevent Chemical Crossover in Li Metal Batteries

“…Such gel has a high viscosity of 4191.47 cp, meanwhile it is still able to wet the electrode due to the high fluidity as compared to pure SSEs, thus greatly improving the interfacial contact between the electrolyte and the lithium anode with original defects. [ 40,41 ]…”

“…Such gel has a high viscosity of 4191.47 cp, meanwhile it is still able to wet the electrode due to the high fluidity as compared to pure SSEs, thus greatly improving the interfacial contact between the electrolyte and the lithium anode with original defects. [40,41] Another important parameter, Li transfer number (t Li+ ) is always used to evaluate the electrochemical capability of the electrolyte. The cells were assembled by placing GPEs between two pure Li metal.…”

Wetting Phenomena and their Effect on the Electrochemical Performance of Surface‐Tailored Lithium Metal Electrodes in Contact with Cross‐linked Polymeric Electrolytes

“…While liquid electrolytes mostly show ac omplete wetting of rough Li metal surfaces,S Es face an underlying challenge to achieve homogeneous and intimate solid-solid contacts. [41,42] TheL ij inorganic electrolyte interface reveals certain issues, and also polymer-based electrolytes show limitations,w ith wetting microscale defects on the Li metal surface. [43] In literature,t he effects of such defect sites on the Li electrodeposition have been reported for liquid and inorganic electrolytes ( Figure 1b).…”

“…The wetting phenomena of Li metal surfaces by electrolytes become crucial when microsized defect sites are present. While liquid electrolytes mostly show a complete wetting of rough Li metal surfaces, SEs face an underlying challenge to achieve homogeneous and intimate solid–solid contacts . The Li|inorganic electrolyte interface reveals certain issues, and also polymer‐based electrolytes show limitations, with wetting microscale defects on the Li metal surface .…”

Benetzungsvorgänge und ihr Einfluss auf die elektrochemischen Eigenschaften von oberflächenangepassten Lithium‐Metall‐Elektroden in Kontakt mit quervernetzten Polymer‐Elektrolyten

“…Die Benetzungsphänomene des Elektrolyten auf Li‐Oberflächen werden entscheidend, wenn mikroskopisch kleine Defektstellen vorhanden sind. Während Flüssigelektrolyte meist eine vollständige Benetzung von rauen Li‐Oberflächen zeigen, liegt die grundlegende Herausforderung von SEs in der Ausbildung gleichmäßiger und enger Festkörper‐Festkörper‐Kontakte . Die Grenzfläche zwischen Li und anorganischen Elektrolyten weist daher Probleme auf und auch Polymer‐basierte Elektrolyte zeigen Limitierungen bei der Benetzung von mikroskaligen Defektstellen auf der Li‐Oberfläche .…”