Functional protective coatings based on polysaccharides and single-ion conducting polymers for metal batteriesVargas Ordaz, Mariana (Avtor) Dominko, Robert (Mentor) lithium-metal batteriesprotective coatingssingle-ion-conducting polymerspolysaccharidesinterfacial chemistrymagnesium metal anodesThe practical application of lithium-metal batteries (LMBs) remains hindered by the intrinsic instability of Li metal, which promotes high-surface-area lithium growth, uncontrolled electrolyte decomposition, and a mechanically fragile interface that fails to withstand the volumetric changes during cycling. This thesis addresses these challenges by developing and elucidating the protective mechanism of polysaccharide and single-ion-conducting polymer (SICP)-based coatings to stabilize the Li-electrolyte interface, regulate Li⁺ transport, and enable uniform metal deposition. Across both liquid and solid-state electrolytes, these coatings demonstrated substantial improvements in interfacial stability, Li utilization, and long-term cycling reversibility. This thesis is divided into three main sections: the first focuses on synthetic pathways to evaluate polysaccharides as platforms for incorporating lithium-conducting functionalities. Cellulose derivatives showed good mechanical properties but were hindered by limited solubility and incomplete grafting, while cyclodextrins offered improved reactivity and enabled successful LiMTFSI conjugation. The second part centers on establishing a physical coating formulation and elucidating its mechanism. First, we established a multifunctional blend incorporating TDMSC, P(LiMTFSI), and LiNO₃ and validated it electrochemically in a liquid electrolyte. This composite formed a smooth, conformal, and ionically conductive matrix that reduced polarization, yielded compact Li deposits, and suppressed the formation of high-surface-area Li. These improvements were confirmed across both liquid and solid-state cells, highlighting the versatility of the approach. To understand how the coating affects the observed performance, we combined operando EIS and OCV measurements with cryo-FIB/ToF-SIMS and XPS analyses, revealing that the coating forms a porous yet compact, electrolyte-permeable interface that regulates Li⁺ flux and diminishes electrolyte decomposition. Finally, the third block extends the coating strategy to magnesium metal to evaluate its applicability in multivalent systems. TDMSC–P(LiMTFSI) films containing Mg(TFSI)₂ improved Mg morphology and increased magnesium utilization. Operando EIS shows a promising translation of the polymeric matrix while underscoring the particular challenges of divalent-ion coordination. 20262026-04-17 15:55:02Doktorsko delo/naloga181886VisID: 25424COBISS_ID: 277468163sl