Resilience‐Enhancing Additive Design Enabled by Macrocyclic Additive‐Mediated Failure Suppression in Lithium‐Ion Batteries

The high‐voltage operation of mid‐nickel NCM Li‐ion batteries (LIBs) increases the energy density but accelerates cell degradation owing to transition‐metal dissolution and oxygen‐radical formation. In this study, the macrocyclic additive 1,4,7,10,13‐pentaazacyclopentadecane is introduced, which enhances cell resilience through a dual‐protection mechanism. The additive spontaneously chelates the dissolved Mn ions, suppressing their migration and subsequent contamination at the negative electrode. Additionally, the Mn‐captured additive deactivates the oxygen radicals generated under high‐voltage conditions, mitigating gas evolution and electrolyte decomposition. This sequencing–scavenging mechanism prevents active Li consumption, stabilizes interfacial layers, and reduces impedance growth. As a result, the cells incorporating the additive exhibit significantly improved cycling stability, reduced capacity fading, and suppressed gas evolution, even under harsh operating conditions. This study demonstrates a new additive design strategy that overcomes the limitations of conventional film‐forming additives and provides an effective approach for enhancing the long‐term durability and performance of high‐energy LIBs.