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

Abstract

Nonaqueous Li−air batteries with ultrahigh theoretical energy density have attracted much attention in the development of clean energy technology. However, a series of safety challenges including the flammable, volatile organic liquid electrolyte, together with the electrolyte decomposition have greatly hindered their practical development. Solid‐state electrolytes with superior mechanical strength, good chemical stability under open‐air system, wide electrochemical window, nonflammable properties provide a feasible strategy to overcome the safety issues and achieve a stable, applicable Li−air battery system. In this article, a comprehensive review of solid‐state Li−air batteries is provided. Based on the overall understanding of the necessity of developing a solid‐state Li−air battery and ion migration mechanism in solid electrolytes, the construction strategies of solid‐state Li−air battery including cathode fabrication, Li anode optimization, electrolyte design, and the interface regulation between electrodes and electrolyte are presented. The prospects of solid‐state Li−air batteries are also proposed at the end. It is expected that this review would provide a systematic understanding and theoretical guidance in designing and developing safe, stable, applicable solid‐state Li−air batteries.

Hybrid Ceramic-Gel Polymer Electrolyte with a 3D Cross-Linked Polymer Network for Lithium–Oxygen Batteries

“…Rechargeable lithium–oxygen batteries (LOBs), with their energy density far exceeding that of lithium-ion batteries, show great application prospects in response to the growing energy demand. − Liquid electrolytes (LEs) have become a focus of attention due to their high ionic conductivity at room temperature and good contact with electrodes. − However, conventional LOBs have severe safety problems caused by the evaporation, leakage, flammability, and electrochemical instability of the organic LEs. Although the excellent mechanical strength, wider electrochemical window, higher thermal stability, and higher Li + transference number of solid-state electrolytes (SSEs) in open working environments divert certain attention, the development of SSEs is still in an embryonic stage owing to the limited triple-phase reaction sites (electrolyte/O 2 /cathode) and the poor interface contact between SSEs and electrodes caused by the inherent solid–solid phase contact. ,, Gel polymer electrolytes (GPEs), which combine the advantages of the high conductivity of LEs and the strong mechanical properties of SSEs, become an excellent choice for LOBs. − …”

“…Although the excellent mechanical strength, wider electrochemical window, higher thermal stability, and higher Li + transference number of solid-state electrolytes (SSEs) in open working environments divert certain attention, the development of SSEs is still in an embryonic stage owing to the limited triple-phase reaction sites (electrolyte/O 2 /cathode) and the poor interface contact between SSEs and electrodes caused by the inherent solid− solid phase contact. 7,9,10 Gel polymer electrolytes (GPEs), which combine the advantages of the high conductivity of LEs and the strong mechanical properties of SSEs, become an excellent choice for LOBs. 11−13 Succinonitrile (SN, NC−CH 2 −CH 2 −CN), a representative plastic crystalline material, becomes an excellent solid solvent for dissolving lithium salts due to its high polarity and phase transformation at a specific temperature.…”

Solid‐state Li–air batteries: Fundamentals, challenges, and strategies

“…Solid‐state electrolyte (SSE) emerges as a promising substitute for liquid electrolyte, possessing superior stability (in thermal, chemical, and electrochemical aspects), wide electrochemical window, favorable mechanical strength, and cost efficiency 24 . These merits enable solid‐state LABs to get rid of electrolyte evaporation and thus guarantee intact reaction interface, restrain the dendrite penetration and anode corrosion, eliminate the risks of battery combustion and explosion, and effectively enlarge working potentials and temperature range, then effectuate enhanced safety and life span as practical LABs expected 25–27 . However, the development of solid‐state LABs is still in its infancy, facing several challenges, such as poor interfacial contact and/or low ionic conductivities of SSEs, limited triple‐phase boundaries in the cathode, and questionable durability for the open‐air circumstance 27–29 .…”

Anchoring NiO Nanosheet on the Surface of CNT to Enhance the Performance of a Li-O2 Battery

“…Researchers are devoted to seeking high-energy and clean energy storage facilities to replace non-renewable resources. With a super-high theory energy density of 3500 Wh kg −1 , Li-O 2 batteries are poised to become the next generation of rechargeable systems to store energy [ 1 , 2 , 3 , 4 ]. Particularly, in an aprotic Li-O 2 battery system, lithium peroxide (Li 2 O 2 ) is recognized as the main discharge product, and is generated via the oxygen reduction reaction (ORR) and its decomposition into Li + ions and O 2 through the oxygen evolution reaction (OER) during the recharge process [ 5 , 6 ].…”