Improved High Rate and Temperature Stability using an Anisotropically Aligned Pillar-Type Solid Electrolyte Interphase for Lithium-ion Batteries.

Numerous reports have elucidated the advantages of SiOx-based anodes including their large capacities and superior cycling stabilities. However, these electrodes have not been optimized for use in electric vehicles (EVs), which demand even better performance stability at fast charging rates and high temperatures. Herein, we fabricated a novel solid electrolyte interphase (SEI) using nanodiamondseeds. The grown SEI comprised an assembly of pillars, with a height and diameter of approximately 600 and 250 nm, respectively. As a result, the Li||Ti-SiOx@C cell with a nanodiamond-containing electrolyte achieved a high capacity retention of 76.4% over 1000 cycles at 5 A g-1 and 50 °C, whereas the cell with no nanodiamond seeds showed a severe decay in the capacity and retained only 61.5% of its initial capacity. Furthermore, the NCM811||Ti-SiOx@C full cell constructed with the pillar-type SEI also showed a high capacity retention of 61.8% at 5 C (1 C = 200 mAh g-1) and 50 °C after 500 cycles, which was a significant improvement from the value (33.3%) demonstrated by its counterpart comprising the conventional SEI. The results obtained herein will enable the development of high-performance lithium-ion batteries.