Sodium metal has shown great potential as an inexpensive anode for rechargeable batteries. However, the growth of sodium dendrites continues to hinder the commercialization of Na metal batteries. Herein, an effective ...Sodium metal has shown great potential as an inexpensive anode for rechargeable batteries. However, the growth of sodium dendrites continues to hinder the commercialization of Na metal batteries. Herein, an effective strategy using anion-anchoring halloysite nanotube(HNT) coating was proven to prevent the diffusion of anions and trigger uniform Na deposition. Through theoretical calculation, a model of active site of fixed anions exposed from HNTs after acid activation was established for the first time, revealing that Si–Al sites are effective active site of acid-activated HNTs. Furthermore, HNTs with strong and effective adsorption capacity for anions were obtained by controlling the structure of HNTs to regulate the exposure of Si–Al sites. The strong interaction between sites of acid-activated HNTs and the SO_(3)CF_(3)^(-) anion effectively promotes the dissociation of sodium salts, the release of Na^(+) and subsequent migration. As a result, HNTs acid activation for 4 h shows a steady sodium deposition process and displays high Coulombic efficiency in half cell, long cycle life in symmetric cell and full cell. This work provides a basic theoretical basis for the design of nanoclay with abundant and effective active site to fix anions for dendritic free metal batteries.展开更多
基金supported by the National Key R&D Program of China (2022YFE0201300)the China Postdoctoral Science Foundation (2022M712948)+2 种基金the CUG Scholar Scientific Research Funds at China University of Geosciences (Wuhan) (2019152)the Fundamental Research Funds for the Central Universities at China University of Geosciences (Wuhan)the National Science Fund for Distinguished Young Scholars (51225403)。
文摘Sodium metal has shown great potential as an inexpensive anode for rechargeable batteries. However, the growth of sodium dendrites continues to hinder the commercialization of Na metal batteries. Herein, an effective strategy using anion-anchoring halloysite nanotube(HNT) coating was proven to prevent the diffusion of anions and trigger uniform Na deposition. Through theoretical calculation, a model of active site of fixed anions exposed from HNTs after acid activation was established for the first time, revealing that Si–Al sites are effective active site of acid-activated HNTs. Furthermore, HNTs with strong and effective adsorption capacity for anions were obtained by controlling the structure of HNTs to regulate the exposure of Si–Al sites. The strong interaction between sites of acid-activated HNTs and the SO_(3)CF_(3)^(-) anion effectively promotes the dissociation of sodium salts, the release of Na^(+) and subsequent migration. As a result, HNTs acid activation for 4 h shows a steady sodium deposition process and displays high Coulombic efficiency in half cell, long cycle life in symmetric cell and full cell. This work provides a basic theoretical basis for the design of nanoclay with abundant and effective active site to fix anions for dendritic free metal batteries.
