High-Performance Li-O-2 Batteries Enabled by Dibenzo-24-Crown-8 Aldehyde Derivative as Electrolyte Additives

Aprotic Li-O-2 batteries (LOB) with high theoretical energy density usually experience cathode clogging by insoluble Li2O2, along with high charge overpotential from its insulating nature. A dibenzo-24-crown-8 aldehyde derivative (DB24C8A) is employed as an additive to enhance the binding strength with Li+, hence promoting the solubility of Li2O2. The generated [DB24C8A center dot Li+] avoids the parasitic reactions caused by reactive O-2(-). Thus, the LOB achieves a large discharge capacity of 6939 mAh g(-1) at 200 mA g(-1) and a high Li2O2 yield (approximate to 93%). Moreover, DB24C8A facilitates the efficient decomposition of Li2O2 via Li+ coordination during the charge process, reducing the charge overpotential to 0.77 V and prolonging the lifetime of the LOB over 213 cycles at 1000 mAh g(-1) and 500 mA g(-1). This work provides a novel approach to boost the performance of LOB by incorporation of crown ether-based compounds to regulate the Li2O2 growth and decomposition pathway.