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Item Divergent Electrically Conductive Pathways in Yttrium-Based 2- and 3-Dimensional Metal–Organic Frameworks(American Chemical Society, 2024-07) Welty, Connor; Gormley, Eoghan L.; Oppenheim, Julius J.; Dincă, Mircea; Hendon, Christopher H.; Stadie, Nicholas P.Despite most porous framework solids exhibiting insulating character, some are known to conduct electrical charge. The peak performing conductive metal–organic frameworks are composed of redox-active hexasubstituted triphenylene linkers, but the impact of redox activity on material conductivity remains enigmatic because of limited availability of direct structure–function relationships. Here, we report a hexagonal yttrium-based conductive porous scaffold, comprising hexahydroxytriphenylene connected by Y-chains (YHOTP). In comparison to its known porous cubic counterpart (Y6HOTP2), this material features a 1000-fold increase in peak conductivity in polycrystalline samples (∼10–1 S cm–1). Furthermore, through a comparison of their electronic structures, we rationalize the origin of this difference and highlight the role of charge carrier concentration in dictating bulk electrical conductivity. Together, this work provides a design principle for the development of next-generation conductive porous frameworks.Item Biochar as a Renewable Substitute for Carbon Black in Lithium-Ion Battery Electrodes(American Chemical Society, 2022-09) Kane, Seth; Storer, Aksiin; Xu, Wei; Ryan, Cecily; Stadie, Nicholas P.Lignin-derived biochar was prepared and characterized toward potential applications as a conductive electrode additive and active lithium host material within lithium-ion batteries (LIBs). This biochar was specifically selected for its high electrical conductivity, which is comparable to that of common conductive carbon black standards (e.g., Super P). Owing to its high electrical conductivity, this biochar serves as an effective conductive additive within electrodes comprising graphite as the active material, demonstrating slightly improved cell efficiency and rate capability over those of electrodes using carbon black as the additive. Despite its effectiveness as a conductive additive in LIB anodes, preliminary results show that the biochar developed in this work is not suitable as a direct replacement for carbon black as a conductive additive in LiFePO4 cathodes. This latter insufficiency may be due to differences in particle geometry between biochar and carbon black; further optimization is necessary to permit the application of biochar as a general-purpose conductive additive in LIBs. Nevertheless, these investigations combined with an assessment of greenhouse gas emissions from biochar production show that replacing carbon black with biochar can be an effective method to improve the sustainability of LIBs.