Mechanistic Insights into Self-Limiting Si–F CEI Formation via a Molecularly Designed Sacrificial Additive

doi:10.1016/j.ensm.2026.105105

Mechanistic Insights into Self-Limiting Si–F CEI Formation via a Molecularly Designed Sacrificial Additive

2026-04-09

0

PRE

AI

Dmitry Bravo‐Zhivotovskii *

DOI：10.1016/j.ensm.2026.105105

Original

Original request for help

Save

Abstract

En 中文

High-nickel layered cathodes, such as NCM811, promise high energy density for next-generation lithium-ion batteries but suffer from interfacial degradation, irreversible capacity loss, and transition metal dissolution under high-voltage operation. Here, a sacrificial silyl ketone additive, bis(di-tert-butylmethylsilyl) ketone, (MetBu2Si)2CO, is introduced to simultaneously modulate cathode–electrolyte interphase (CEI) formation and suppress parasitic reactions. (MetBu2Si)2CO undergoes preferential oxidation during the first cycle, forming a self-limiting, thin, and uniform protective layer while scavenging HF, as evidenced by Si 2p XPS and 19F NMR studies. Furthermore, in situ XRD reveals that (MetBu2Si)2CO mitigates lattice distortions during the first cycle. Because of these multifunctional roles, our new additive is shown to significantly improve capacity retention and perform better than previously reported organosilicon additives. These results establish (MetBu2Si)2CO as a sacrificial, self-limiting additive that leads to the formation of an interphase ensuring long-term cathode stabilization, thus offering a molecular-level strategy to enable durable high-voltage lithium-ion battery operation.

Keywords:

High-nickel layered cathodes

Cathode–electrolyte interphase

Sacrificial additive

HF scavenging

Lattice distortion mitigation

Mechanistic Insights into Self-Limiting Si–F CEI Formation via a Molecularly Designed Sacrificial Additive

Abstract

Journal

Organization