Critical drawbacks, including sluggish redox kinetics and undesirable shuttling of polysulfides (Li S , n = 4-8), seriously deteriorate the electrochemical performance of high-energy-density lithium-sulfur (Li-S) batteries. Herein, these challenges are addressed by constructing an integrated catalyst with dual active sites, where single-atom (SA)-Fe and polar Fe N are co-embedded in nitrogen-doped graphene (SA-Fe/Fe N@NG). The SA-Fe, with plane-symmetric Fe-4N coordination, and Fe N, with triangular pyramidal Fe-3N coordination, in this well-designed configuration exhibit synergistic adsorption of polysulfides and catalytic selectivity for Li S lithiation and Li S delithiation, respectively. These characteristics endow the SA-Fe/Fe N@NG-modified separator with an optimal polysulfides confinement-catalysis ability, thus accelerating the bidirectional liquid-solid conversion (Li S ↔Li S) and suppressing the shuttle effect. Consequently, a Li-S battery based on the SA-Fe/Fe N@NG separator achieves a high capacity retention of 84.1% over 500 cycles at 1 C (pure S cathode, S content: 70 wt%) and a high areal capacity of 5.02 mAh cm at 0.1 C (SA-Fe/Fe N@NG-supported S cathode, S loading = 5 mg cm ). It is expected that the outcomes of the present study will facilitate the design of high-efficiency catalysts for long-lasting Li-S batteries.
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http://dx.doi.org/10.1002/adma.202100171 | DOI Listing |
ACS Nano
January 2025
School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China.
Sulfurized polyacrylonitrile (SPAN) exhibits a very high cycle stability by overcoming the shuttle effect of conventional Li-S batteries. However, there are still controversies in SPAN about the bonding types of sulfur with the matrix, their critical synthesis temperature regions, and their roles in the electrochemical lithium storage reaction, seriously hindering the economical synthesis of SPAN, the optimization of performances, and the exploration of other SPAN-like alternatives. The key to solving the above problems lies in accurate measurements of the thermodynamic evolution of bonding interactions in the synthesis process as well as in the electrochemical process.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
South China Normal University, Chemistry, 55 W Zhongshan Rd, 510006, Guangzhou, CHINA.
Lithium-sulfur (Li-S) batteries has been regarded as one of the most promising next-generation energy storage systems due to their high theoretical energy density. However, the practical application of Li-S batteries is still hindered by the unstable cathode-electrolyte interphase and the early passivation of charge product (Li2S), leading to poor cycling stability and low S utilization. Herein, we propose an electrolyte engineering strategy using highly solvating hexamethylphosphoramide (HMPA) as a co-solvent to elucidate the dissociation-precipitation chemistry of lithium polysulfides (LiPSs).
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
School of Chemistry, South China Normal University, Guangzhou 510006, P. R. China.
This work develops 1,1'-oxalyldiimidazole (ODI) as a functional electrolyte additive. This film-forming additive improves the wide range of temperature and rate performances of LiNiCoMnO/graphite (NCM811) batteries. After 1200 cycles at room temperature (25 °C), the discharge capacity retention rate is 51.
View Article and Find Full Text PDFNature
January 2025
Beijing Key Laboratory for Theory and Technology of Advanced Battery Materials, School of Materials Science and Engineering, Peking University, Beijing, China.
With promises for high specific energy, high safety and low cost, the all-solid-state lithium-sulfur battery (ASSLSB) is ideal for next-generation energy storage. However, the poor rate performance and short cycle life caused by the sluggish solid-solid sulfur redox reaction (SSSRR) at the three-phase boundaries remain to be solved. Here we demonstrate a fast SSSRR enabled by lithium thioborophosphate iodide (LBPSI) glass-phase solid electrolytes (GSEs).
View Article and Find Full Text PDFChem Sci
January 2025
School of Materials and Energy, University of Electronic Science and Technology of China Chengdu 611731 China
Silicon (Si) is considered a promising anode material for next-generation lithium-ion batteries due to its high theoretical specific capacity and earth-abundancy. However, challenges such as significant volume expansion, unstable solid electrolyte interphase (SEI) formation in incompatible electrolytes, and slow lithium-ion transport lead to its poor cycling and rate performance. In this work, it is demonstrated that superior cyclability and rate capability of Si anodes can be achieved using ethyl fluoroacetate (EFA) and fluoroethylene carbonate (FEC) solvents with low binding energy with Li but with sufficiently high relative dielectric constants.
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