Rational Engineering of p-n Heterogeneous ZnS/SnO 2 Quantum Dots with Fast Ion Kinetics for Superior Li/Na-Ion Battery

• Published in: Small (Weinheim an der Bergstrasse, Germany) Germany), 2023-10, Vol.19 (43), p.e2300534
• Main Authors: Zhan, Guang-Hao, Liao, Wen-Hua, Hu, Qian-Qian, Wu, Xiao-Hui, Huang, Xiao-Ying
• Format: Article
• Language: English
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.202300534

Constructing heterogeneous nanostructures is an efficient strategy to improve the electrical and ionic conductivity of metal chalcogenide-based anodes. Herein, ZnS/SnO quantum dots (QDs) as p-n heterojunctions that are uniformly anchored to reduced graphene oxides (ZnS-SnO @rGO) are designed and engineered. Combining the merits of fast electron transport via the internal electric field and a greatly shortened Li/Na ion diffusion pathway in the ZnS/SnO QDs (3-5 nm), along with the excellent electrical conductivity and good structural stability provided by the rGO matrix, the ZnS-SnO @rGO anode exhibits enhanced electronic and ionic conductivity, which can be proved by both experiments and theoretical calculations. Consequently, the ZnS-SnO @rGO anode shows a significantly improved rate performance that simple counterpart composite anodes cannot achieve. Specifically, high reversible specific capacities are achieved for both lithium-ion battery (551 mA h g at 5.0 A g , 670 mA h g at 3.0 A g after 1400 cycles) and sodium-ion battery (334 mA h g at 5.0 A g , 313 mA h g at 1.0 A g after 400 cycles). Thus, this strategy to build semiconductor metal sulfides/metal oxide heterostructures at the atomic scale may inspire the rational design of metal compounds for high-performance battery applications.