Molecular-level designed single electrolyte additive with multifunctional groups enabling high mechanical properties/fast Li+ kinetics interphase for wide-temperature nickel-rich/graphite batteries.

[Display omitted] • Molecularly designed SOFPB incorporates the merits of various functional groups. • SOFPB endows NCM622 or graphite electrode with wide-temperature performance. • NCM622/graphite full-cells with SOFPB stably cycle over -10 °C to 55 °C. High-voltage nickel-rich/graphite full-cells offer significant potential for enhancing the energy density of lithium-ion batteries (LIBs), yet rapid capacity degradation at extreme temperatures remains a critical challenge. We introduce a novel electrolyte additive, 5-(t-butyldimethylsilyloxy)-2-fluorophenylboronic acid pinacol ester (SOFPB), which incorporates multifunctional boron, phenyl-, fluorine, and siloxy groups to tackle this issue. In Li/NCM622 half-cells, 0.3 wt% SOFPB achieves a capacity retention 2.6 times that of the Baseline after 400 cycles at -30 °C, and maintains 78.4% and 77.5% capacity after 300 cycles at 25 °C and 55 °C, respectively, compared to 63.4% and 3.8% for the Baseline. This improvement is attributed to a robust cathode electrolyte interphase (CEI) with high lithium-ion conductivity and oxidative stability. Li/graphite half-cells with SOFPB show rapid capacity recovery at 0 °C and retain 99.6% and 72.4% capacity after 500 and 150 cycles at 25 °C and 55 °C, respectively, compared to 60.3% for the Baseline at 25 °C. This performance is due to a flexible solid electrolyte interphase (SEI) that improves lithium-ion diffusion. Furthermore, NCM622/graphite full-cells highlight the practical value of SOFPB, with retention of 91.6%/77.7%/97.7% after 200/150/50 cycles at 25 °C/-10 °C/55 °C, respectively, compared to 52.9%/25.2%/43.9% for the Baseline. The multifunctional design of SOFPB provides valuable insights for developing advanced electrolyte additives for high-voltage LIBs with broad climate adaptability. [ABSTRACT FROM AUTHOR]