Elektrolyte für wiederaufladbare Lithium‐Luft‐Batterien

Abstract

Lithium (Li)‐Luft‐Batterien sind wegen ihrer enorm hohen Energiedichte vielversprechend für die elektrochemische Energiespeicherung. Es ist jedoch nach wie vor schwierig, praktische Li‐Luft‐Batterien zu erhalten, da sie eine starke Kapazitätsabnahme und eine geringe Entladungsrate aufweisen. Die verwendeten Elektrolyte stehen unter dem Verdacht, Zellversagen zu verursachen. In diesem Aufsatz liegt der Fokus auf den Chancen und Herausforderungen, die mit der Wahl des Elektrolyten für wiederaufladbare Li‐Luft‐Batterien einhergehen. Eine Zusammenfassung der Reaktionsmechanismen, internen Zusammensetzungen, Instabilitätsfaktoren, Auswahlkriterien und Design‐Ideen hinter den untersuchten Elektrolyten wird bereitgestellt, um Strategien zur Erfüllung der jeweiligen Batterieanforderungen entwickeln zu können. Insbesondere ionisch‐flüssige (IL‐)Elektrolyte und Festkörperelektrolyte bieten gute Möglichkeiten, sowohl die hohe Energiedichte als auch die Sicherheit zu kontrollieren.

Synthesis and Characterization of Aero-Eutectic Graphite Obtained by Solidification and Its Application in Energy Storage: Cathodes for Lithium Oxygen Batteries

“…The potential vs. capacity curves of Figure 8 shows that the battery accomplishes twenty complete cycles, keeping the capacity value fixed. The results were similar to those of previous reports using the same electrolyte [5,34]. Notice that the twenty limited discharge-charge cycles at 1.2 mAh cm −2 gives an accumulated capacity of 24 mAh cm −2 , which is equivalent to conventional 48 cycles limited to 0.5 mAh cm −2 .…”

Fundamental Understanding and Construction of Solid‐State Li−Air Batteries

“…To achieve an ideal solid electrolyte, the construction of composite electrolyte by taking advantage of the synergistic effect of the different types of electrolyte composition and compensating for each drawback is surely regarded as an effective means. [ 34 ] The commonly studied composite solid electrolyte can be divided into the following two main categories: inorganic–organic composite solid electrolyte, solid–liquid composite electrolyte.…”

“…For the generation of thick Li 2 CO 3 layer covered on the surface of the garnet solid electrolyte caused by the side reaction between the garnet-type solid electrolyte and CO 2 , various surface polishing processes, heat treatment, and recently the carbon treatment is utilized to remove the Li 2 CO 3 layer from the solid electrolyte. [14,34,66] It is generally assumed that the introduction of solid-state electrolyte could well overcome the challenge of Li dendrites, but in fact, this challenge still exists for some solidstate electrolyte, especially for the type of garnet-structured LLZO with high electronic conductivity, Li dendrites are likely to grow along the grain boundary and interconnected pores inside the solid electrolyte, resulted in short circuit and battery failure after several cycles. [67] Constructing dense solid electrolyte with little pores and cracks, thermal treatment, thin dense alloying layer on solid electrolyte provide an appropriate solution in inhibiting the growth of Li dendrites.…”

Review and Recent Advances of Oxygen Transfer in Li‐air Batteries

“…The oxygen in the porous air electrode needs to be dissolved in the electrolyte first, and then participate in the oxidation reduction reaction. Therefore, the dissolution and diffusion of oxygen in the electrolyte are the most important factors which is limiting the capacity and power density of Li‐air batteries [28,29,35–41] . The narrow channel in the porous air electrode for oxygen transferring leads to a slow oxygen diffusion rate.…”