Interphasial Engineering via Individual Moiety Functionalized Organosilane Single-Molecule for Extreme Quick Rechargeable SiO/NCM811 Lithium-Ion Batteries

The individual moiety-functionalized organosilane single molecule, that is, 1,1,1,5,5,5-hexamethyl-3-[(trimethylsilyl)oxy]-3-vinyltrisiloxane (TMSV), is investigated as an electrolyte additive for a less charge-consuming and viscoelastic solid electrolyte interphase (SEI) forming agent, finally accomplishing extremely quick (6 min) rechargeable SiO/NCM811 lithium-ion batteries. The moiety of the vinyl group serves with a poly(ethylene oxide)-like viscoelastic SEI film on the SiO electrode, which provides a physicochemically stable interphase during long-term cycling. The increase of DC-iR due to electrolyte decomposition on the continuously exposed SiO surface with cycling is inhibited by the alternated SEI composition. Degradation of bulk electrolyte solution caused by thermal decomposition of the LiPF6 salt is also suppressed by the trimethylsilyl moiety in the TMSV additive, which scavenges HF. Owing to the multifunctionality of TMSV, the cycle performance of laminated pouch full cells comprising high-nickel-contented NCM811 positive electrode and SiO-enriched negative electrode is significantly improved at both room and elevated temperatures. Furthermore, the 6 min quick recharging cycle performance is also enhanced by the TMSV additive.

Automated summary

The individual moiety-functionalized organosilane single molecule TMSV serves as an electrolyte additive, forming a viscoelastic SEI film on the SiO electrode in SiO/NCM811 lithium-ion batteries, improving cycle performance and quick recharge capability. The multifunctionality of TMSV inhibits electrolyte decomposition and enhances the stability of the battery system during cycling, leading to improved performance at both room and elevated temperatures in laminated pouch full cells.