ABSTRACT The practical application of lithium‐oxygen batteries (LOBs) is hindered by lithium dendrite growth, cathode product accumulation, and electrolyte leakage. Rather than addressing these issues in isolation, we design a strategy employing a quasi‐solid polymer electrolyte based on on a dual‐salt (LiTFSI and LiNO 3 ) and dual‐polymer (PVDF‐HFP/PEO) system, where LiNO 3 serves as a multifunctional filler to synergistically optimize the electrolyte, anode, and cathode. Theoretical calculations reveal that the C–H···F interactions between PEO and PVDF‐HFP optimize the Li + coordination environment, while LiNO 3 disrupts polymer chain ordering and expands amorphous regions. These combined effects enable the electrolyte to achieve a high ionic conductivity of 1.19 mS cm − 1 and a Li + transference number of 0.63 at room temperature. Furthermore, NO 3 − undergoes in situ reduction on the lithium anode surface, inducing the formation of a LiF‐rich SEI layer that effectively suppresses dendrite growth. Its derived NO 2 − /NO 2 redox mediators catalyze the decomposition of Li 2 O 2 , reducing the charge overpotential to 0.44 V and alleviating cathode passivation. Consequently, the multi‐walled carbon nanotube (MWCNT) cathode‐based LOBs achieve a high specific capacity of 14,076 mAh g − 1 and stable cycling for nearly 300 cycles. This provides a new paradigm for designing single‐component fillers to achieve multifunctional integration of electrolytes.
Xia et al. (2026) studied this question.