POS10-1463
Molecular-Level Understanding of Dual-Electrode Interphase Stabilization by a Molecularly Functionalized Separator
Topic
S10. AI-assisted Design and Simulation of Polymers
When and Where
Sep 30, 2026
08:30 - 09:30
Room 301 (Grand Ballroom)
Session Chairs
Heesuk KIM
Jinhye BAE
Presenter(s)
Jiyoon Lee (Hanyang University)
Co-Author(s)
Abstract
Lithium metal batteries (LMBs) paired with Ni-rich NCM811 cathodes offer high energy density, but practical use is hindered by interfacial instability at both electrodes. Trace moisture hydrolyzes PF5, a LiPF6 decomposition product, generating hydrofluoric acid (HF) that corrodes the cathode and triggers transition metal (TM) dissolution. Dissolved TMs migrate to the lithium anode, accelerating dendritic growth and consuming both electrodes and electrolyte, calling for a strategy that regulates interfacial chemistry at both electrodes simultaneously. Here, we present a molecularly functionalized separator (MFS) based on fluorinated graphene oxide with polar fluorine- and oxygen-containing groups that spatially modulate interfacial reactions at both electrodes. Density functional theory calculations elucidate the mechanism of this dual-electrode stabilization. At the cathode, three roles are investigated: PF5 stabilization, TM chelation, and HF scavenging. PF5 bound to MFS shows suppressed hydrolysis versus free PF5, and hydroxyl-derived PF5OH likewise resists further hydrolysis. TM ions show favorable binding energies with MFS, indicating spontaneous chelation, while edge C-F bonds favorably scavenge HF. At the anode, MFS species show a strong binding affinity to the Li metal anode, promoting LiF formation, which is crucial for stabilizing the Li metal anode. These insights reveal how a functionalized separator governs interfacial reaction pathways at both electrodes, providing molecular-level design principles for multifunctional separators in LMBs.
