A conversion‐chemistry‐based zinc–selenium aqueous battery is reported that delivers high specific capacity, good rate capability, and excellent cycle life. In this work, an electronically conjugated covalent triazine framework is used to physicochemically lock selenium (Se8) clusters. As a control sample, the traditional melt‐diffusion approach is used to physically lock Se8. While the melt‐diffused selenium cathode exhibited a precipitous drop in capacity with cycling, the physicochemically locked selenium cathode can be cycled in a stable manner and delivered a specific capacity of ≈600 mAh g−1with a capacity retention of ≈70% after 1000 continuous charge/discharge steps. Ab initio density functional theory calculations and various structural and morphological characterizations indicate that the superiority of the physicochemically locked selenium cathode stems from its ability to suppress the polyselenide shuttle phenomenon and thus prevent loss of active material during cycling. This work opens the door toward the development of conversion chemistries for high performing, non‐flammable, and low‐cost zinc‐based rechargeable batteries.
- Award ID(s):
- 2003783
- PAR ID:
- 10544559
- Publisher / Repository:
- ACS
- Date Published:
- Journal Name:
- Journal of the American Chemical Society
- Volume:
- 145
- Issue:
- 41
- ISSN:
- 0002-7863
- Page Range / eLocation ID:
- 22762 to 22775
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Premise The ecological implications of hyperaccumulation have been investigated at the organismal level, but are poorly understood at the plant community level. Questions addressed here were: Does the presence of selenium (Se) hyperaccumulators affect Se distribution and concentration in their native soil, and do hyperaccumulators affect overall vegetation properties and species composition?
Methods Plant survey and soil Se mapping were performed at three seleniferous sites in Colorado. In season one, plots with and without hyperaccumulators were compared for (1) bare ground, canopy cover, and species richness; (2) relative species abundance; (3) soil Se distribution and concentration. In season two, a smaller‐scale design was implemented, focusing on areas 3 m in diameter around hyperaccumulators versus nonhyperaccumulators in 44 paired plots on one site.
Results Plots with hyperaccumulators generally showed more bare ground, less canopy cover, higher species richness, and 2–3‐fold higher soil Se levels. These patterns were not consistently significant across all sites; the effects of hyperaccumulators may have been diluted by their low abundance and the relatively large area of survey. In the smaller‐scale study, highly significant results were obtained, showing more bare ground, less canopy cover, and higher species richness in plots with hyperaccumulators; soil Se concentration was also higher in plots with hyperaccumulators.
Conclusions Hyperaccumulators may significantly affect local soil Se concentration and vegetation over at least a 3 m diameter area, or 4× their canopy. These differences may result from the combined positive and negative allelopathic effects observed earlier at the organismal level.
