Journal of the Chinese Ceramic Society, Volume. 52, Issue 2, 428(2024)
Catalysis in Lithium-Sulfur Batteries: Origin and Prospect
Lithium-sulfur (Li-S) battery is considered as a next generation energy storage system with a great application prospect because of its high theoretical energy density (i.e., 2 600 W·h/kg), low cost and environmental friendliness. However, the shuttling of lithium polysulfides (LiPSs) is considered as one of the main bottlenecks hindering the commercial application of Li-S batteries. Conventional physical confinement and chemisorption are proved to be important strategies to solve a problem of shuttle effect, but they are still “passive” solutions and cannot solve the problem from the source. The shuttle effect is due to the slow transformation of the liquid intermediate LiPSs (i.e., Li2Sn, 4≤n≤8) to the solid product Li2S2/Li2S, which accumulates continuously in the electrolyte and diffuses to the negative electrode driven in the concentration gradient and electric field. The introduction of high-efficiency catalysts can reduce the energy barrier of sulfur conversion, accelerate a “solid-liquid-solid” conversion process, improve the utilization of sulfur, and inhibit the shuttle effect, playing a key role in improving the capacity and cycling performance of the battery. Therefore, a further understanding the sulfur conversion process in Li-S battery chemistry and putting forward the fundamental method to promote the rapid conversion of LiPSs and the uniform deposition of solid products from the perspective of electrocatalytic reaction kinetics can have important theoretical value and practical significance for promoting the practical development of Li-S battery.In the chemical industry, catalysts can reduce the activation energy of chemical reactions and increase the reaction rate. The desulfurization technology in conventional sulfur chemistry gives inspirations for the catalysis in Li-S battery. The key to this technology is that the C—S bond in petroleum distillate is broken by multi-step catalytic hydrogenation, and sulfur is gradually removed in the form of H2S. The charge-discharge process of Li-S battery involves the conversion of solid phase S8, liquid phase polysulfide (i.e., Li2Sn, 4≤n≤8) and solid phase Li2S2/Li2S. The reaction process is similar to the industrial step-by-step desulfurization process.In this review, from the perspective of battery chemistry for Li-S batteries, the origin of the catalysis for Li-S batteries, catalytic mechanism and research progress of catalysts were summarized, and the activity descriptors guiding the rational design of catalysts for Li-S batteries were proposed. Finally, the future development of Li-S batteries was prospected. The idea of industrial desulfurization was introduced into Li-S battery to realize the combination of conventional chemical engineering and Li-S battery chemistry. The “lithium-sulfur catalysis” strategy is demonstrated as a “proactive” solution to the problem of shuttle effect of Li-S batteries, accelerating the transformation of polysulfides and reducing their accumulation in electrolyte, which is expected to fundamentally inhibit the shuttle effect. Since 2014, transition metal oxides, sulfides, nitrides and carbides have been developed as effective catalysts for Li-S battery. In addition, heterostructure catalysts with different functions have been also developed with multi-functions. With the comprehensive understanding of the sulfur redox process, selective catalysis, bidirectional catalysis and homogeneous catalysis have been proposed. Recent development on quantum chemistry and AI technology provides a novel research method for reasonable prediction and analysis of the properties and reaction process of catalysts. Several key activity descriptors, such as the lattice matching, orbital hybridization and p charge density are developed to guide the rational design of catalysts. However, there are some differences in the performance of different types of catalysts, the relevant internal reasons still need to be further revealed, and the universality of descriptors also need to be further explored.Summary and prospects “Lithium-sulfur catalysis” is considered as an important strategy to solve the bottleneck of practical application of Li-S batteries. Although a variety of catalytic material systems are developed, the catalytic mechanism still remains unclear, and advanced theories need to guide the rational design of high-efficiency catalysts. Therefore, it is extremely urgent to develop a novel lithium-sulfur battery system and explore an effective research paradigm of Li-S catalysis for the conversion reaction process of Li-S battery. Future research directions focus on three aspects: 1) The failure mechanism and stability of catalysts should be investigated; 2) The structure-activity relationship between the electronic structure and catalytic performance of the catalyst should be deeply explored by AI technology; and 3) The conversion mechanism of solid-state Li-S battery should be clarified, and a novel practical solid-state Li-S battery system should be constructed for some future extreme applications.
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JIANG Xin, ZHANG Chen, LV Wei, ZHANG Bingsen, YANG Quan-Hong. Catalysis in Lithium-Sulfur Batteries: Origin and Prospect[J]. Journal of the Chinese Ceramic Society, 2024, 52(2): 428
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Received: Jun. 29, 2023
Accepted: --
Published Online: Aug. 5, 2024
The Author Email: Quan-Hong YANG (qhyangcn@tju.edu.cn)
CSTR:32186.14.