Crown Ether Electrolyte Induced Li2O2 Amorphization for Low Polarization and Long Lifespan Li-O2 Batteries.
Angew Chem Int Ed Engl
; 63(27): e202403521, 2024 Jul 01.
Article
em En
| MEDLINE
| ID: mdl-38654696
ABSTRACT
Lithium-oxygen batteries possess an extremely high theoretical energy density, rendering them a prime candidate for next-generation secondary batteries. However, they still face multiple problems such as huge charge polarization and poor life, which lay a significant gap between laboratory research and commercial applications. In this work, we adopt 15-crown-5 ether (C15) as solvent to regulate the generation of discharge products in lithium-oxygen batteries. The coronal structure endows C15 with strong affinity to Li+, firmly stabilizes the intermediate LiO2 and discharge product Li2O2. Thus, the crystalline Li2O2 is amorphized into easily decomposable amorphous products. The lithium-oxygen batteries assembled with 0.5â
M C15 electrolyte show an increased discharge capacity from 4.0â
mAh cm-2 to 5.7â
mAh cm-2 and a low charge overpotential of 0.88â
V during the whole lifespan at 0.05â
mA cm-2. The batteries with 1â
M C15 electrolyte can cycle stably for 140â
cycles. Furthermore, the amorphous characteristic of Li2O2 product is preserved when matched with redox mediators such as LiI, with the charge polarization further decreasing to 0.74â
V over a cycle life of 190â
cycles. This provides new possibilities for electrolyte design to promote Li2O2 amorphization and reduce charge overpotential in lithium-oxygen batteries.
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MEDLINE
Idioma:
En
Ano de publicação:
2024
Tipo de documento:
Article