A functional slurry additive for robust interphase and stabilized high-voltage nickel-rich cathodes in lithium-ion batteries

Nickel-rich LiNi_0.8Co_0.1Mn_0.1O₂ (NCM811) cathodes are promising candidates for next-generation lithium-ion batteries (LIBs) due to their high energy density. However, their practical application is limited by inherent challenges, such as microcrack formation during demanding cycling, which destabilizes the cathode-electrolyte interface. This instability accelerates capacity degradation and transition metal dissolution, significantly reducing battery lifespan. To address these issues, we introduce 4-(ethoxy) trimethylolpropane tri-acrylate (EOTA) as a multifunctional slurry additive to construct robust cathode-electrolyte interface (CEI) layer. The EOTA additive enables the in-situ formation of a robust, protective interfacial layer on the cathode surface during cycling. This CEI layer effectively suppresses side reactions, mitigates structural degradation, and reduces transition metal dissolution, as confirmed through comprehensive characterization. As a result, NCM811||Li half-cells achieve fast charging capability at a high cutoff voltage of 4.5 V, with significantly improved capacity retention compared to bare NCM811 cathodes. Additionally, Graphite||NCM811 full cells deliver an impressive 87.1 % capacity retention after 200 cycles, while pouch cells maintain 79.8 % capacity retention after 500 cycles. This study presents a simple yet effective strategy to overcome interfacial challenges in nickel-rich cathodes, providing a new pathway toward the development of high-performance, long-lasting lithium-ion batteries.