Volcano Plot of Transition Metal Disulfides in Aqueous Zinc Ion Storage.

Huang, Zihao; Jia, Jun; Liu, Xin; Li, Jiahao; Guo, Yuzheng; Liang, Hanfeng · Nano Lett · 2026

basic_science · Level V

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Abstract

The rational design of cathode materials for aqueous zinc-ion batteries (AZIBs) has been guided by the principle that larger interlayer spacing facilitates greater Zn<sup>2+</sup> storage. However, this geometric heuristic fails to explain the stark performance difference between isostructural transition metal disulfides (TMDs) like VS<sub>2</sub> and MoS<sub>2</sub>, which possess similar spacings but vastly different capacities. Herein, we propose an electronic-structure descriptor, <i>φ</i>, defined as the product of the transition metal's d-band center and electronegativity. Density functional theory calculations reveal that <i>φ</i> strongly correlated with Zn<sup>2+</sup> adsorption energy (R<sup>2</sup> = 0.94). Experimental validation across six synthesized TMDs confirms a definitive volcano-type relationship between Zn<sup>2+</sup> storage capacity and <i>φ</i>, while revealing no correlation with interlayer spacing. This work establishes a generalizable screening principle that prioritizes the electronic origin of host-guest interactions over traditional structural metrics, providing a new roadmap for the rational design of intercalation hosts for multivalent-ion batteries.