Efficient anion immobilization enabled by structurally controllable halloysite for dendrite-free sodium metal anode  

作　　者：Caihong Yang Yicheng Hua Ying Zhang Jie Wang Huanwen Wang Liangjie Fu Aidong Tang Huaming Yang 

机构地区：[1]Engineering Research Center of Nano-Geomaterials of Ministry of Education,China University of Geosciences,Wuhan 430074,China [2]Laboratory of Advanced Mineral Materials,China University of Geosciences,Wuhan 430074,China [3]Faculty of Materials Science and Chemistry,China University of Geosciences,Wuhan 430074,China [4]College of Chemistry and Chemical Engineering,Central South University,Changsha 410083,China [5]Hunan Key Laboratory of Mineral Materials and Application,School of Minerals Processing and Bioengineering,Central South University,Changsha 410083,China

出　　处：《Science China Chemistry》2023年第9期2600-2611,共12页中国科学（化学英文版）

基　　金：supported by the National Key R&D Program of China (2022YFE0201300);the China Postdoctoral Science Foundation (2022M712948);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)。

摘　　要：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.

关 键 词：HALLOYSITE anion immobilization ion transport sodium dendrites sodium metal batteries 

分 类 号：TM912[电气工程—电力电子与电力传动] TG146.26[一般工业技术—材料科学与工程]