Synergistic Morphology and Electron Modulation Engineering Enables Cation-Anion Cointercalation and Conversion Chemistry.

Zha, Zhiyuan; Chen, Ruinan; Zhang, Daohong; Wang, Qiufan · Nano Lett · 2026

basic_science · Level V

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Abstract

While bismuth chalcogenides have attracted considerable attention for their quantum topological states and spintronic application, there are few studies on bismuth chalcogenides in the field of ammonium-ion batteries (AIBs). Herein, a dual engineering strategy combines tungsten doping and morphological modulation to unlock Bi<sub>2</sub>Te<sub>3</sub> for AIBs. Density functional theory calculations verify that W doping induces electron delocalization, and Bi vacancies create localized charge accumulation. The electronic recombination enables a reversible cation-anion coinsertion accompanied by a conversion reaction mechanism in W-Bi<sub>2-<i>x</i></sub>Te<sub>3</sub>, which delivers 220 mAh g<sup>-1</sup> at 0.3 mA with exceptional cycling stability with over 2500 cycles at 3 A g<sup>-1</sup>. The constructed aqueous "rocking-chair" AIB based on W-Bi<sub>2-<i>x</i></sub>Te<sub>3</sub>//MnO<sub>2</sub> exhibits a large reversible capacity of 156.56 mAh g<sup>-1</sup> at 0.15 A g<sup>-1</sup> and a long lifespan of 2000 cycles. This work provides a facile electron engineering strategy on topological insulator as advanced anode for a new generation of AIBs.