ScholarWorks@성균관대학교

초록

The rational design of Prussian blue analogs (PBAs) with tailored architectures is essential for advancing aqueous zinc-ion batteries (AZIBs). Here, a hollow bimetallic Ni-Mn hexacyanoferrate (H-NiMnHCF) cathode is synthesized through a Kirkendall-effect-mediated route, in which the Ni content is systematically tuned to optimize shell thickness, structural uniformity, and electrochemical functionality. Ni incorporation induces controlled void formation and homogeneous Mn-Ni alloying, while enhancing electronic conductivity and suppressing Jahn-Teller (JT) distortions associated with Mn & sup3;(+). Density-functional theory (DFT) calculations reveal a reduction in axis-selective bond anisotropy (Delta L-1 from approximate to 12.4% to approximate to 7.3%) and a narrowed bandgap with increased electronic states near the Fermi level, consistent with the experimentally observed low charge-transfer resistance. The Kirkendall-derived hollow morphology further increases the active surface and shortens Zn & sup2;(+) diffusion pathways, enabling rapid ion transport and reversible redox kinetics. The optimized 1/2 Ni electrode delivers high capacity, low interfacial resistance, and excellent cycling retention (87.6% after 1000 cycles). Moreover, gel-electrolyte pouch cells exhibit stable performance under bending, cutting, and puncturing, demonstrating mechanical robustness and safety. This study presents a morphology-composition co-optimization strategy and offers mechanistic insights for designing structurally stable, high-rate PBA cathodes for next-generation AZIBs.

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