Enabling Reversible Reaction by Uniform Distribution of Heterogeneous Intermediates on Defect‐Rich SnSSe/C Layered Heterostructure for Ultralong‐Cycling Sodium Storage. Issue 26 (31st May 2022)

• Record Type: Journal Article
• Authors: Cao, Liang; Fang, Shaojun; Xu, Baohe; Zhang, Bao; Wang, Chunhui; Xiao, Zhiming; Zou, Guoqiang; Hou, Hongshuai; Ou, Xing; Ji, Xiaobo
• Is Part Of: Small. Volume 18:Issue 26(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-05-31
• Subjects: anode materials -- defect engineering -- heterogeneous intermediate -- layered SnSSe -- sodium‐ion batteries; Nanotechnology -- Periodicals; Nanoparticles -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1002/smll.202202134
• Languages: English
• ISSNs: 1613-6810

Abstract

Abstract: 2D layered Sn‐based materials have attracted enormous attention due to their remarkable performance in sodium‐ion batteries. Nevertheless, this promising candidate involves a complex Na + ‐storage process with multistep conversion‐alloying reactions, which induces the uneven dispersion of heterogeneous intermediate accompanied by severe agglomeration of metallic Sn 0, inescapably resulting in poor reaction reversibility with sluggish rate capability and inferior cyclic lifespan. Herein, a delicately layered heterostructure SnSSe/C consisting of defect‐rich SnSSe and graphene is designed and successfully achieved via a facile hydrothermal process. The equal anionic substitution of Se in SnSSe crystal can trigger numerous defects, which can not only facilitate Na + diffusion but also accelerate the nucleation process by inducing quantum‐dot‐level uniform distribution of heterogeneous intermediates, Na2 Se/Na2 S and Sn 0 . Concurrently, in situ formed uniform Na2 Se/Na2 S grain boundaries confined by this unique layered heterostructure may effectively suppress the agglomeration of metallic Sn 0 nanograins and boost the reversibility of conversion‐alloying reaction. As a result, the SnSSe/C displays significant improvement in Na‐storage performance, in terms of remarkable rate capability and ultralong cycling lifespan. This work, focusing on controlling intermediate distribution, provides an effective strategy to boost reaction reversibility, which can be wildly employed in conversion‐based electrodes for energy storage regions. Abstract : A defects‐rich SnSSe/C layered heterostructure is designed as anode for sodium‐ion batteries. Owing to the defects and homogeneously distributed S and Se atoms within SnSSe, the uniformly dispersed Sn 0 /Na2 S/Na2 Se intermediates are in‐situ formed during conversion reaction, which enhances the Na + diffusion kinetic and boost the reversibility of reactions. As expected, it displays significant improvement in Na‐storage performance.