Resilience-Enhancing Additive Design Enabled by Macrocyclic Additive-Mediated Failure Suppression in Lithium-Ion...

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.