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Abstract Aqueous zinc‐ion batteries are promising alternatives to lithium‐ion batteries due to their cost‐effectiveness and improved safety. However, several challenges, including corrosion, dendrites, and water decomposition at the Zn anode, hinder their performance. Herein, an approach is proposed, that deviates from the conventional design by adding water into a propylene carbonate‐based organic electrolyte to prepare a non‐flammable “water‐in‐organic” electrolyte. The chaotropic salt Zn(ClO4)2exploits the Hofmeister effect to promote the miscibility of immiscible liquid phases. Interactions between propylene carbonate and water restrict water activity and mitigate unfavorable reactions. This electrolyte facilitates preferential Zn (002) deposition and the formation of solid electrolyte interphase. Consequently, the “water‐in‐organic” electrolyte achieves a 99.5% Coulombic efficiency at 1 mA cm−2over 1000 cycles in Zn/Cu cells, and constant cycling over 1000 h in Zn/Zn symmetric cells. A Na0.33V2O5/Zn battery exhibits impressive cycling stability with a capacity of 175 mAh g−1for 800 cycles at 2 A g−1. Additionally, this electrolyte enables sustainable cycling across a wide temperature range from −20 to 50 °C. The design of a “water‐in‐organic” electrolyte employing a chaotropic salt presents a potential strategy for high‐performance electrolytes in zinc‐ion batteries with a large stability window and a wide temperature range.
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Low-Concentration Electrolyte Design for Wide-Temperature Operation in Sodium Metal Batteries
Sodium metal batteries (SMBs) are cost-effective and environmentally sustainable alternative to lithium batteries. However, at present, limitations such as poor compatibility, low coulombic efficiency (CE), and high electrolyte cost hinder their widespread application. Herein, we propose a non-flammable, low-concentration electrolyte composed of 0.3 M NaPF6in propylene carbonate (PC), fluoroethylene carbonate (FEC), and 1,1,2,2-tetrafluoroethyl 2,2,3,3-tetrafluoropropyl ether (TTE). This low-concentration electrolyte not only reduces cost but also delivers rapid ion diffusion and superior wetting properties. While the Na||FePO4system with this electrolyte demonstrates slightly reduced performance at room temperature compared to standard-concentration formulations (S-PFT), it excels at both high (55 °C) and low (−20 °C) temperatures, showcasing its balanced performance. At 0.5 C (charge)/1 C (discharge), capacity retention reaches 92.8% at room temperature and 98.5% at elevated temperature, with CE values surpassing 99% and 99.63%, respectively, and significant performance sustained at −20 °C at 0.2 C. This electrolyte development thus offers a well-rounded, economically viable path to high-performance SMBs for diverse environmental applications.
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- Award ID(s):
- 2208840
- PAR ID:
- 10563844
- Publisher / Repository:
- The Electrochemical Society
- Date Published:
- Journal Name:
- Journal of The Electrochemical Society
- Volume:
- 172
- Issue:
- 1
- ISSN:
- 0013-4651
- Format(s):
- Medium: X Size: Article No. 010501
- Size(s):
- Article No. 010501
- Sponsoring Org:
- National Science Foundation
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