Understanding Moisture and Carbon Dioxide Involved Interfacial Reactions on Electrochemical Performance of Lithium–Air Batteries Catalyzed by Gold/Manganese-Dioxide

Abstract

Lithium-air (Li-air) battery works essentially based on the interfacial reaction of 2Li + O2 ↔ Li2O2 on the catalyst/oxygen-gas/electrolyte triphase interface. Operation of Li-air batteries in ambient air still remains a great challenge despite the recent development, because some side reactions related to moisture (H2O) and carbon dioxide (CO2) will occur on the interface with the formation of some inert byproducts on the surface of the catalyst. In this work, we investigated the effect of H2O and CO2 on the electrochemical performance of Li-air batteries to evaluate the practical operation of the batteries in ambient air. The use of a highly efficient gold/δ-manganese-dioxide (Au/δ-MnO2) catalyst helps to understand the intrinsic mechanism of the effect. We found that H2O has a more detrimental influence than CO2 on the battery performance when operated in ambient air. The battery operated in simulated dry air can sustain a stable cycling up to 200 cycles at 400 mA g(-1) with a relatively low polarization, which is comparable with that operated in pure O2. This work provides a possible method to operate Li-air batteries in ambient air by using optimized catalytic electrodes with a protective layer, for example a hydrophobic membrane.

The Stabilization Effect of CO2 in Lithium–Oxygen/CO2 Batteries

“…This results in high charge overpotentials, low coulombic efficiencies (CEs), and short battery lifespan. Therefore, researchers suggest that CO 2 should be completely removed from the Li–air batteries to make the reactions easier . Based on these results, the impact of CO 2 seems to be fully understood and subsequently, the investigations on CO 2 in Li–O 2 batteries have not received much attention.…”

Bi2S3/Ketjen Black as a Highly Efficient Bifunctional Catalyst for Long‐Cycle Lithium‐Oxygen Batteries

“…XPS were conducted to analyze the chemical states of the catalysts during cycling. The peak at 290 eV in C 1s spectra indicates the presence of Li 2 CO 3 (Figure a) . Note that from the pristine state to the 100th cycle, the relative intensity of Li 2 CO 3 and oxygen functional groups has obviously increased.…”

“…The peak at 290 eV in C 1s spectra indicates the presence of Li 2 CO 3 (Figure 6a). [50,51] Note that from the pristine state to the 100th cycle, the relative intensity of Li 2 CO 3 and oxygen functional groups has obviously increased. These formation of Li 2 CO 3 can be attributed to the decomposition of carbon materials and electrolyte as a result of the reactions with oxidative Li 2 O 2 and LiO 2 .…”

Tailoring Asymmetric Discharge‐Charge Rates and Capacity Limits to Extend Li‐O2 Battery Cycle Life

“…The depth of discharge is a crucial consideration for Li‐O 2 batteries systems. It has been widely shown that the primary failure mechanisms for Li‐O 2 batteries involve the accumulation of by‐products formed by side reactions between Li 2 O 2 (and its intermediates) and the electrolyte and cathode . These side reactions are particularly problematic at high charging voltages and become more pronounced as cycle number increases .…”