Multifunctional SiO2 dense nanopore sieve for ultra-stable Zn metal anodes under high current densities
Constructing solid electrolyte interphase (SEI) layer is a highly desirable strategy to tackle Zn dendrite and side reactions. However, sluggish diffusion kinetics of Zn2+ within SEI layer limits the high-current performance of Zn anodes. Herein, multifunctional SiO2 dense nanopore sieves are synthe...
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Veröffentlicht in: | Journal of power sources 2024-12, Vol.623, p.235445, Article 235445 |
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Format: | Artikel |
Sprache: | eng |
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Zusammenfassung: | Constructing solid electrolyte interphase (SEI) layer is a highly desirable strategy to tackle Zn dendrite and side reactions. However, sluggish diffusion kinetics of Zn2+ within SEI layer limits the high-current performance of Zn anodes. Herein, multifunctional SiO2 dense nanopore sieves are synthesized to protect Zn anodes. It mitigates corrosion and hydrogen evolution, increases exchange current density and Zn2+ transference number, and reduces activation energy and nucleation overpotential. The cycling lifespan of symmetrical cells is extended to 4000 h at 10 mA cm−2/1 mAh cm−2, 500 h at 20 mA cm−2/1 mAh cm−2, 232 h at 50 mA cm−2/1 mAh cm−2. Coulombic efficiency of asymmetrical cell is increased to 99.78 % after 7679 cycles at 5 mA cm−2/1 mAh cm−2. In Zn//MnVO full cells, SiO2 dense nanopore sieve significantly enhances cycling stability and rate capability, achieving a reversible capacity of 76 mAh g−1 after 1000 cycles at 3 A g−1. As evidenced experimentally and theoretically, SiO2 dense nanopore sieve facilitates efficient and homogeneous transport of high-flux Zn2+, eliminates water-mediated parasitic reactions, and shields SO42−/OH− anions, resulting in dendrite-free, uniform and reversible Zn deposition with a preferred Zn (002) orientation. This is attributed to unique dense nanopores, hydroxyl groups and surface negative charges.
•SiO2 dense nanopore sieve is presented as a SEI protective layer for Zn anode.•Dense nanopores enable the swift uniform transport of high-flux Zn2+ ions.•Highly hydrophilic hydroxyl groups aid in desolvation and dehydration.•Negative surface charges induce an electrostatic shielding effect against SO42− ions. |
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ISSN: | 0378-7753 |
DOI: | 10.1016/j.jpowsour.2024.235445 |