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Creators/Authors contains: "Oyekunle, Ifeoluwa"

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  1. Polycrystalline ion conductors are widely used as solid electrolytes in energy storage technologies. However, they often exhibit poor ion transport across grain boundaries and pores. This work demonstrates that strategically tuning the mesoscale microstructures, including pore size, pore distribution, and chemical compositions of grain boundaries, can improve ion transport. Using LiTa2PO8as a case study, we have shown that the combination of LiF as a sintering agent with Hf4+implantation improves grain-grain contact, resulting in smaller, evenly distributed pores, reduced chemical contrast, and minimized nonconductive impurities. A suite of techniques has been used to decouple the effects of LiF and Hf4+. Specifically, LiF modifies particle shape and breaks large pores into smaller ones, while Hf4+addresses the chemical mismatches between grains and grain boundaries. Consequently, this approach achieves nearly two orders of magnitude improvement in ion conduction. Tuning mesoscale structures offers a cost-effective method for enhancing ion transport in polycrystalline systems and has notable implications for synthesizing high-performance ionic materials. 
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    Free, publicly-accessible full text available May 16, 2026
  2. The Cl–S mixed-anion sublattice of Li1.6AlCl3.4S0.6creates face- and edge-shared octahedra that connect to form 3D ion conduction pathways with low activation energy barriers. 
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    Free, publicly-accessible full text available January 29, 2026
  3. Free, publicly-accessible full text available January 10, 2026
  4. Li3.6In7S11.8Cl has a face-centered cubic arrangement of S2−/Clstabilized by Li+/In3+that form 3D ion conduction paths. The moisture stability and fast ion conduction make Li3.6In7S11.8Cl a promising electrolyte for solid-state batteries. 
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    Free, publicly-accessible full text available January 1, 2026
  5. Abstract All‐solid‐state potassium batteries emerge as promising alternatives to lithium batteries, leveraging their high natural abundance and cost‐effectiveness. Developing potassium solid electrolytes (SEs) with high room‐temperature ionic conductivity is critical for realizing efficient potassium batteries. In this study, we present the synthesis of K2.98Sb0.91S3.53Cl0.47, showcasing a room‐temperature ionic conductivity of 0.32 mS/cm and a low activation energy of 0.26 eV. This represents an increase of over two orders of magnitude compared to the parent compound K3SbS4, marking the highest reported ionic conductivity for non‐oxide potassium SEs. Solid‐state39K magic‐angle‐spinning nuclear magnetic resonance on K2.98Sb0.91S3.53Cl0.47reveals an increased population of mobile K+ions with fast dynamics. Ab initio molecular dynamics (AIMD) simulations further confirm a delocalized K+density and significantly enhanced K+diffusion. This work demonstrates diversification of the anion sublattice as an effective approach to enhance ion transport and highlights K2.98Sb0.91S3.53Cl0.47as a promising SE for all‐solid‐state potassium batteries. 
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