Regulating the P-band center of SnS2-SnO2 heterostructure to boost the redox kinetics for high-performance lithium-sulfur battery

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2024-06, Vol.490, p.151526, Article 151526
• Main Authors: Liu, Wendong, Feng, Junan, Zhang, Chaoyue, Shi, Chuan, Chen, Shuangqiang, Wang, Tianyi, Zhao, Xiaoxian, Zhang, Lixue, Song, Jianjun
• Format: Article
• Language: English
• Subjects: Heterostructure; Lithium–sulfur battery; P band center; Redox kinetics
• ISSN: 1385-8947
• DOI: 10.1016/j.cej.2024.151526

[Display omitted] In this work, SnS2-SnO2-CNTs heterostructure was constructed to modify both the separator and cathode, which promotes the movement of the P band center of the tin atom to the Fermi level, realizing the association process of adsorption, capture, and conversion of LPSs, thus achieving high-performance Li-S battery. •SnS2-SnO2 heterostructure is designed to modify both separator and cathode for Li-S battery.•The formation of heterostructure regulates the movement of the P band center of Sn.•SnS2-SnO2 reduces the deposition barrier of Li2S and promotes redox kinetics.•Superior performance achieved under high rate or high S loading. Lithium-sulfur batteries (LSBs) are considered a strong contender for the new-generation secondary energy storage system due to their high capacity and energy density. However, the sluggish reaction kinetics and the shuttle effect of lithium polysulfides (LPSs) severely hinder the cycle stability. The robust design of both the separator and cathode exhibit an effective role in restricting the shuttle effect and accelerating redox kinetics through the LPSs trapping and catalyzing effect. In this paper, a CNT-modified tin sulfide and tin oxide (SnS2-SnO2-CNTs) heterostructure was constructed as a multifunctional catalyst to modify both the separator and cathode to achieve high-performance LSBs. The formation of SnS2-SnO2 heterostructure promotes the movement of the P band center of the tin atom to the Fermi level, which realizes the association process of adsorption, capture, and conversion of LPSs, thus effectively suppressing the shuttle effect. The SnS2-SnO2 heterogeneous interface can also reduce the deposition barrier of Li2S, thus greatly promoting the redox kinetics. Together with the improved electron transfer, the resulting LSBs with the robust electrode and separator exhibit superior electrochemical performance with a high initial capacity of 930.2 mAh g−1 at 1 C with a high sulfur loading of 4.3 mg cm−2 and a remarkable capacity of up to 580.3 mAh g−1 at an ultrahigh rate of 7.4 C.