Critical Advances in Ambient Air Operation of Nonaqueous Rechargeable Li–Air Batteries

Abstract

Over the past few years, great attention has been given to nonaqueous lithium-air batteries owing to their ultrahigh theoretical energy density when compared with other energy storage systems. Most of the research interest, however, is dedicated to batteries operating in pure or dry oxygen atmospheres, while Li-air batteries that operate in ambient air still face big challenges. The biggest challenges are H2O and CO2 that exist in ambient air, which can not only form byproducts with discharge products (Li2O2), but also react with the electrolyte and the Li anode. To this end, recent progress in understanding the chemical and electrochemical reactions of Li-air batteries in ambient air is critical for the development and application of true Li-air batteries. Oxygen-selective membranes, multifunctional catalysts, and electrolyte alternatives for ambient air operational Li-air batteries are presented and discussed comprehensively. In addition, sepa-rator modification and Li anode protection are covered. Furthermore, the challenges and directions for the future development of Li-air batteries are presented

Two‐Dimensional Transition Metal Chalcogenides for Alkali Metal Ions Storage

“…[38,39] Therefore, 2D TMDs have aroused great research interest and are considered promising versatile electrodes in EES devices,i ncluding LIBs, SIBs, PIBs, and AICs [30,36,40] as wella sh igh-energy Li-S and Li-O 2 batteries (Scheme 2). [41][42][43] Various 2D TMDs-based electrode materials have been prepared via mechanical exfoliation, [44] chemical vapor deposition (CVD), [45,46] liquid exfoliation, [47][48][49] and chemical synthesis. [30,50] However, the van der Waals attraction between TMD nanosheets makes them prone to aggregate during electrode fabrication, reducing the accessible surfacea reas and undermining the electrochemical performance unique to the 2D structures in LIB, SIBs, and PIBs.…”

“…[59] Introduction of carbon materials, metal oxides, or MXenen anosheets to form 2D TMDs composites or 2D heterojunction has been demonstrated to be an effectives trategy to improvet he energy storage characteristics of 2D TMDs in LIBs, SIBs, PIBs as well as high-energyL i-S and Li-O 2 batteries. [43,[60][61][62] Recently,s everal reviews summarized the preparation methodso f2 DTMD nanomaterials as well as their electrochemical applicationsi nL IBs, supercapacitors, and electrocatalysts. [51,[62][63][64] However,f ew of them focus on 2D TMDs-based hybrid materialsf or the alkali-metal-ion storage properties, especially for SIBs, PIBs, AICs, and high-energy Li-S batteries.…”

“…Furthermore, the thin and flexible characteristics of 2D TMD nanosheets make it possible to construct flexible LIBs, SIBs, and emerging EES devices . Therefore, 2D TMDs have aroused great research interest and are considered promising versatile electrodes in EES devices, including LIBs, SIBs, PIBs, and AICs as well as high‐energy Li–S and Li–O 2 batteries (Scheme ) …”

“…Similar to Li–S batteries, the soluble polychalcogenides intermediates produced in situ could be dissolved in ether‐based electrolytes, giving rise to the polychalcogenide shuttle effect, which results in large irreversibility, effusion of active anode materials, inferior cycling stability, and low round‐trip efficiencies . Introduction of carbon materials, metal oxides, or MXene nanosheets to form 2D TMDs composites or 2D heterojunction has been demonstrated to be an effective strategy to improve the energy storage characteristics of 2D TMDs in LIBs, SIBs, PIBs as well as high‐energy Li–S and Li–O 2 batteries . Recently, several reviews summarized the preparation methods of 2D TMD nanomaterials as well as their electrochemical applications in LIBs, supercapacitors, and electrocatalysts .…”

Developing Practical Lithium-Air Batteries by Avoiding Negative Effects of CO₂

“…Besides understanding the reaction mechanism of CO2 in LABs, a better way to LABs is to completely remove the CO2 from the breathing air before it enters the LAB system 34,35 . However, removing CO2 from the breathing air proved to be a significant challenge 36 . A filter with a specific pore size does not work well due to the small difference in the kinetic radius of the CO2 and O2 molecules.…”