2026-10-11T11:02:22Z https://api.figshare.com/v2/oai

oai:figshare.com:article/34050532 2026-10-01T21:09:07Z category_1 category_4 category_873 category_734 category_122 portal_63 item_type_2 month_year_10_2026

Cross-Linked Polyphosphazene Solid Polymer Electrolytes with Partially Immobilized Anions for Stable Lithium Metal Batteries Ye-eun Han (14774638) Seung Yoon Lee (11704712) Jae Jun Kim (11074491) Daun Jeong (647177) Hee Joong Kim (1618264) Jong-Chan Lee (1545112) Biophysics Biochemistry Chemical Sciences not elsewhere classified Biological Sciences not elsewhere classified Mental Health sup >+</ sup solid polymer electrolytes sem analyses revealed partially immobilized anions eg repeating unit dominant interphase accompanied chain length modulated chain length (< best overall balance anion control electrolyte anchored anionic moieties 90 × 10 60 ° c regulating interfacial lithium lithium metal batteries polyphosphazenes bearing oligo allyloxy side chains 1 – 4 standing network polymerizable single mortem xps low polarization ionic conductivity ion transport intermediate side findings demonstrate ethylene glycol effective platform cells employing >< sub 1000 h Polyphosphazenes pair an inorganic, flame-retardant −PN– backbone with unusually high chain mobility, yet their softness has limited their use as solid polymer electrolytes. Here, we convert that flexibility into a free-standing solid polymer electrolyte by <i>in situ</i> radical cross-linking between polyphosphazenes bearing oligo(ethylene glycol) (EG repeating unit, <i>n</i> = 1–4) and allyloxy side chains (PEGnAP) and a polymerizable single-ion conducting lithium salt (LiMTFSI), thereby simultaneously introducing network-anchored anionic moieties and building a free-standing network. Varying the oligo(ethylene glycol) side-chain length modulated both the ionic conductivity and lithium-ion transference number (<i>t</i>_Li⁺), with an intermediate side-chain length (<i>n</i> = 2, P2SPE0.05) providing the best overall balance, reaching a <i>t</i>_Li⁺ of 0.62 and an ionic conductivity of 1.90 × 10^–4 S cm^–1 at 60 °C. Partial anion immobilization may contributes to more regulated Li⁺ flux and promote stable solid electrolyte interphase (SEI) formation, yielding stable lithium stripping/plating over 1000 h with low polarization. Post-mortem XPS and SEM analyses revealed the formation of an inorganic-dominant interphase accompanied by a uniform lithium surface morphology. Furthermore, LFP/P2SPE0.05/Li cells exhibited improved cycling stability compared to cells employing the P2DEG0.05 mobile-anion control electrolyte. These findings demonstrate that cross-linked polyphosphazenes incorporating single-ion conducting moieties provide an effective platform for regulating interfacial lithium-ion transport and enhancing the stability of lithium metal batteries. 2026-10-01T00:00:00Z Dataset Media 10.1021/acsapm.6c03205.s003 https://figshare.com/articles/media/Cross-Linked_Polyphosphazene_Solid_Polymer_Electrolytes_with_Partially_Immobilized_Anions_for_Stable_Lithium_Metal_Batteries/34050532 CC BY-NC 4.0