A research team from the Department of Energy’s Pacific Northwest National Laboratory reports that the flow battery, a design optimized for electrical grid energy storage, maintained its capacity to store and release energy for more than a year of continuous charge and discharge.
The study, just published in the journal Joule, details the first use of a dissolved β-cyclodextrin to boost battery longevity and capacity. In a series of experiments, the scientists optimized the ratio of chemicals in the system until it achieved 60 percent more peak power. Then they cycled the battery over and over for more than a year, only stopping the experiment when the plastic tubing failed. During all that time, the flow battery barely lost any of its activity to recharge. This is the first laboratory-scale flow battery experiment to report more than a year of continuous use with minimal loss of capacity.
Fluorenone-based flow batteries with the organic additive β-cyclodextrin demonstrate enhanced rate capability, high capacity, and long cycling.
https://www.sciencedaily.com/releases/2023/07/230710180520.htm
Further developments on CD-enabled batteries:
Polyoxometalate-cyclodextrin cluster-organic supramolecular framework (POM-CD-COSF)-based battery separator as an ideal lightweight barrier (ca. 0.3 mg cm−2) was first directly involved in the lithium-sulfur battery (Li−S) system to suppress the polysulfide shuttle effect through supramolecularly recognizing polysulfide guests and then catalyzing their conversion while simultaneously accelerating Li+ ions diffusion.
Prof. Lubin Ni, Jie Gu, Xinyuan Jiang, Hongjie Xu, Zhen Wu, Yuchao Wu, Yi Liu, Prof. Ju Xie, Prof. Yongge Wei, Prof. Guowang Diao (2023) Polyoxometalate-Cyclodextrin-Based Cluster-Organic Supramolecular Framework for Polysulfide Conversion and Guest–Host Recognition in Lithium-sulfur Batteries. Angew. Chem. 62, e202306528. https://doi.org/10.1002/anie.202306528
β-cyclodextrin (β-CD) modified separator was fabricated through simple vacuum filtration. With the merits of the unique properties of the β-CD, such as the “funnel effect”, the ionic conductivity of the modified separator (named CD-separator) rise from 0.24 mS cm−1 to 1.051 mS cm−1. And the CD-separator exhibit a better compatibility with contact angle of 41.9°, lower than that of polyolefin separator of 50.3°. The battery with CD-separator exhibits a high reversible specific capacity of 1036.3 mAh/g at a high current density of 4.0 A/g after 1000 cycles, which much higher than that of the battery with polyolefin separator (e.g. Celgard-2500, 752.8 mAh/g).
Bofeng Wang, Fangli Xiao, Xing Gao, Shilong Dong, Jiatong Li, Haoyang He, Yipeng Cui, Yinming Ding, Jiayang Xie, Lei Zu, Huiqin Lian (2024) β-Cyclodextrin-modified high-performance black phosphorus-based battery separators. Materials Letters 358,135827. https://doi.org/10.1016/j.matlet.2023.135827.
A solid polymer electrolyte based on non-covalent anchoring effect of CD-Si (a new porous polymer obtained by nucleophilic reaction of β-cyclodextrin with SiCl4) and double transmission channels is exploited to suppress Zn dendrites growth and shuttle effect of polyiodide, achieving outstanding cycle-stability of symmetrical batteries and ultralong-life solid-state Zn-I2 battery.
Yang Su, Xinlu Wang, Minghang Zhang, Huimin Guo, Prof. Haizhu Sun, Gang Huang, Prof. Dongtao Liu, Prof. Guangshan Zhu (2023) Porous Cyclodextrin Polymer Enables Dendrite-Free and Ultra-Long Life Solid-State Zn-I2 Batteries. Angew. Chem. 62, e202308182. https://doi.org/10.1002/anie.202308182
α-CD molecules’ unique 3D structure can effectively regulate the mass transfer of the electrolyte components and isolate the Zn anode from H2O molecules. The α-CD provides abundant electrons to the Zn (002) crystallographic plane, which induces charge density redistribution. Such an effect relieves the reduction and aggregation of Zn2+ cations while protecting the Zn metal anode from water molecules. Finally, a small amount of α-CD additive (0.01 M) can enhance the performance of Zn significantly in Zn||Cu cells (1980 cycles with 99.45% average CE) and Zn||Zn cells (8000 h ultra-long cycle life).
Jinzhang Yang, Bosi Yin, Siwen Zhang, Ying Sun, Jiazhuo Li, Dawei Su, Tianyi Ma (2023) Macromolecules Promoting Robust Zinc Anode by Synergistic Coordination Effect and Charge Redistribution. Small 19, 2304913. https://doi.org/10.1002/smll.202304913
The addition of α-CD in aqueous ZnSO4 solution reduces nucleation overpotential and activation energy of Zn plating and suppresses H2 generation. Computational, spectroscopic, and electrochemical studies reveal that α-CD preferentially adsorbs in parallel on the Zn surface via secondary hydroxyl groups, suppressing water-induced side reactions of hydrogen evolution and hydroxide sulfate formation. Additionally, the hydrophilic exterior surface of α-CD with intense electron density simultaneously facilitates Zn2+ deposition and alleviates Zn dendrite formation. A formulated 3 M ZnSO4 + 10 mM α-CD electrolyte enables homogenous Zn plating/stripping (average Coulombic efficiency ∼ 99.90%) at 1 mA cm–2 in Zn|Cu cells and a considerable capacity retention of 84.20% after 800 cycles in Zn|V2O5 full batteries.
Kang Zhao, Guilan Fan, Jiuding Liu, Fangming Liu, Jinhan Li, Xunzhu Zhou, Youxuan Ni, Meng Yu, Ying-Ming Zhang, Hui Su, Qinghua Liu, and Fangyi Cheng (2024) Boosting the Kinetics and Stability of Zn Anodes in Aqueous Electrolytes with Supramolecular Cyclodextrin Additives. J. Am. Chem. Soc. 2022, 144, 25, 11129–11137. https://doi.org/10.1021/jacs.2c00551
Adamantane-polyacrylic acid (AdEN-AA) and β-cyclodextrin-polyacrylic acid (βCD6A-AA) polymers as supramolecular binders of anode material. The anode material prepared in water shows the highest stability, retaining capacities of over 1000 mAhg-1 after 90 cycles vs. 279 mAhg-1 of the electrode prepared in N-methyl-2-pyrrolidone.
M.G. Ortiz, M.A. Sanservino, A. Visintin, G.del C. Pizarro, M.V. Tundidor-Camba, E. Schott, A. Sepulveda, C. Zúñiga, D.P. Oyarzún, R. Martin-Trasancos (2024) β-cyclodextrin and adamantane polyacrylic acid copolymers as supramolecular binder for silicon anodes: N-methylpyrrolidone or water for preparing the slurries? Carbohydrate Polymer Technologies and Applications 7, 100414.
https://doi.org/10.1016/j.carpta.2023.100414.
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