Suppression elevated-temperature transition metal dissolution in LiNi0.5Mn1.5O4 cathode via a HF-resistant bis[3-(trimethoxysilyl)propyl]amine coating

High-voltage spinel LiNi 0.5 Mn 1.5 O 4 (LNMO) emerges as an ideal cathode for high energy density lithium-ion batteries due to its 4.7 V operating voltage and low-cost manganese-rich composition. However, the severe interfacial degradation caused by transition metal dissolution and pervasive electrolyte decomposition compromises practical viability in commercial lithium-ion batteries, critically under elevated-temperature operation. To address this problem, we constructed a covalently anchored bis[3-(trimethoxysilyl)propyl]amine (BTPA) coating layer on the LNMO surface through atomic-scale grafting. The BTPA-coated LNMO confers exceptional cyclic stability and rate capability, representing a transformative advancement in cathode performance. At 50 °C, BTPA-coated LNMO cathode maintains 96.10 % capacity retention after 100 cycles at 1C, significantly outperforming pristine LNMO (58.92 % retention), while demonstrating exceptional rate capability with 109.42 mAh·g −1 delivered at 10C compared to 92.71 mAh·g −1 for the pristine LNMO. The synergistic suppression of Mn 3+ formation and parasitic reactions underpins unprecedented high-temperature cyclability, establishing a paradigm for extreme-condition energy storage.