High‐Performance Li‐O<sub>2</sub> Batteries Enabled by Dibenzo‐24‐Crown‐8 Aldehyde Derivative as Electrolyte Additives
Qi Zhang, S. Nagaraja Rao, Sai V. C. Vummaleti, Eng Tuan Poh, Wenrui Dai, Xinhang Cui, Jishan Wu, Jia Zhang, Wei Chen
Abstract
Abstract Aprotic Li‐O 2 batteries (LOB) with high theoretical energy density usually experience cathode clogging by insoluble Li 2 O 2 , 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 Li 2 O 2 . The generated [DB24C8A•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 Li 2 O 2 yield (≈93%). Moreover, DB24C8A facilitates the efficient decomposition of Li 2 O 2 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 Li 2 O 2 growth and decomposition pathway.