Solid-solution iodine levers the interlayer storage of BiOBr electrode via optimizing the preferred crystal orientation for aqueous batteries

• Published in: Journal of power sources 2024-09, Vol.613, p.234814, Article 234814
• Main Authors: Qin, Tingting, Zhou, Lujia, Fu, Jimin, Dong, Taowen, Han, Yixiao, Qiao, Yingxue, Wang, Xujin, Guo, Zhenbin
• Format: Article
• Language: English
• Subjects: Aqueous battery; BiOX electrode; Interlayer space; Preferred crystal orientation
• ISSN: 0378-7753
• DOI: 10.1016/j.jpowsour.2024.234814

Layered bismuth oxyhalides (BiOX) stand out as promising anode materials for aqueous batteries due to the extensive “interlayer” spaces, theoretically providing ample ion storage sites and efficient ion diffusion channels. However, the efficient development and utilization of “interlayer” spaces remains unsatisfactory. This study presents a proof-of-concept strategy to activate the interlayer storage capabilities of a BiOBr-based electrode through a straightforward solid-solution iodine method. The incorporation of iodine into BiOBr matrix could enhance the preferred (110) crystal orientation, serving as direct entrances to the ion diffusion channels and enabling increased interaction with OH−, thereby potentially optimizing the utilization of “interlayer” spaces. Furthermore, the iodine is conducive to accelerating the charge transfer dynamics. Consequently, the BiOBr0·87I0.13 electrode exhibits a high specific capacity (187.6 mAh g−1 at 1 A g−1) and outstanding rate performance (153.1 mAh g−1 at 4 A g−1). This work levers interlayer storage of layered materials, providing a framework for maximizing utilization of “interlayer” spaces in charge storage and reaction dynamics. •BiOX with ample layered space and diffusion channels are promising for anode.•The solid-solution I levers the interlayer storage activity of BiOBr electrode.•The incorporation of I into BiOBr enhances the preferred (110) crystal orientation.•The (110) crystal orientation provides a direct pathway for ion diffusion channels.