Conductive and catalytic multi-metallic interlayer for high-performance lithium–sulfur batteries

Self-supporting cathodes with conductive composite interlayer for high performance bendable lithium-sulfur batteries

Lithium-sulfur (Li-S) batteries are regarded as one of the most promising next-generation energy storage technologies due to their high theoretical specific capacity, material abundance, and low production costs. Despite these advantages, the commercialization of Li-S batteries remains limited, primarily due to significant technical challenges,1-3 including the dissolution and shuttling of lithium polysulfides (PS), a major cause of fast capacity degradation over cycling in Li-S batteries. In our recent work,4 we introduced a novel sulfur cathode design comprising a thin film of nanolayer-polymer-coated carbons (NPC) deposited on sulfur electrodes (NPC-S). This advanced architecture enabled Li-S battery cells to achieve a high specific capacity of ~1,600 mAh/g, approaching sulfur's theoretical specific capacity, without introducing appreciable dead weight or volume to the battery.In this talk, we will present our continued efforts to further develop the advanced Li-S battery technology with the novel strategy of combining the NPC-S approach with a cycle-stabilizing and safety-enhancing approach in the advanced Li-S batteries. This synergistic strategy resulted in not only the near-theoretical specific capacity of sulfur (Figure 1a), but also a significantly improved long-term cycle stability, ~90% capacity retention after cycling at 1C rate for 500 charge-discharge cycles (Figure 1b). We will present various analytical characterizations and theoretical calculations to elucidate the reaction mechanisms of the outstanding performance of the advanced Li-S battery technology. Acknowledgment This work was supported by the Linda and Larry Pearson Endowed Chair at the Leslie A. Rose Department of Mechanical Engineering, South Dakota School of Mines & Technology, and the South Dakota Governor Research Center for Electrochemical Energy Storage. References Wang, S.; Wang, Z.; Chen, F.; Peng, B.; Xu, J.; Li, J.; Lv, Y.; Kang, Q.; Xia, A.; Ma, L. "Electrocatalysts in lithium-sulfur batteries". Nano Research 2023, 1-30.Zhao, F. L.; Xue, J. H.; Shao, W.; Yu, H.; Huang, W.; Xiao, J. "Toward high-sulfur-content, high-performance lithium-sulfur batteries: Review of materials and technologies". J Energy Chem 2023, 80, 625-657. DOI: 10.1016/j.jechem.2023.02.009.Hu, X.; Huang, T.; Zhang, G.; Lin, S.; Chen, R.; Chung, L.-H.; He, J. "Metal-organic framework-based catalysts for lithium-sulfur batteries.". Coordination Chemistry Reviews 2023, 475, 214879.Hasan, M. W.; Huynh, K.; Lama, B.; Razzaq, A. A.; Smdani, M. G.; Akter, F. N.; Maddipudi, B.; Shende, R.; Paudel, T. R.; Xing, W. "A Highly Effective Polysulfide-Trapping Approach for the Development of High Energy Density, Scalable Lithium-Sulfur Batteries". J Electrochem Soc 2024. DOI: 10.1149/1945-7111/ad3ebf. Figure 1

3D catalytic MOF-based nanocomposite as separator coatings for high-performance Li-S battery

Lithium-sulfur (Li-S) batteries are potential alternatives to lithium-ion batteries, which are known to have certain drawbacks. This has drawn special technological attention. Sulfur’s low electrical conductivity, shuttling of the intermediate polysulfides, the slow conversion reaction kinetics of various lithium polysulfides (LiPS), and the major volume change of sulfur in the lithiation reaction are some of the main issues that still need to be resolved before Li-S batteries can be used in practical applications. Additionally, it is likely because there are not enough prognostic models determining energy densities at the cell and pack level based on materials and cell design, most of the articles do not report system-level metrics, specific energy (Wh kg-1), and energy density (Wh L-1).To overcome these problems, atomic vanadium (V) and cobalt (Co) modified ketjen black-sulfur composite (VCKBS) was prepared and used as a cathode in Li-S batteries. The synthesized composite was characterized by various techniques, e.g., XRD, Raman, SEM, HR-TEM, HAADF-STEM, and XPS spectra. The polysulfide adsorption test showed that V had increased the adsorption ability, and cyclic voltammetry displayed the increased catalytic activity resulting from Co, offering a large number of interfacial active sites and ensuring smooth electron transfer. Cycling performance tests showed an initial specific capacity of 1329 mAh g−1, maintained at 1249 mAh g−1 after 100 cycles. Under a higher sulfur loading (2.4 mg cm−2), at 0.2 C, Li-S cells demonstrated an initial specific capacity of 1201 mAh g−1 and retained 985 mAh g−1 after 300 cycles with a low fading rate of 0.059% per cycle. The rate performance tests showed that the prior capacity is nearly recovered, going from 1C back to 0.1C, demonstrating the superiority of the VCKBS material.In addition to the experimental characterization of the Li-S cell performance, energy densities were also predicted by a proposed system-level performance model. The 1st and 100th discharge capacities were used to forecast the system-level specific energies and energy densities. The system-level specific energies and energy densities based on the 100th discharge capacity of VCKBS cathodes had improvements of 1342 and 568%, respectively. This suggests that an easy route to construct the highly stable cathode material may pave the way for the development of highly efficient Li-S batteries. Acknowledgments Hira Fazal acknowledges support from the Türkiye Scholarship/Research Fellowship Program sponsored by the Prime Ministry of Turkey Presidency for Turks Abroad and Related Communities (21PK070917). Damla Eroglu acknowledges support from the Istanbul Development Agency (Award No: TR10/21/YEP/0001). We also thank the National Natural Science Foundation of China (22171180) and the Science and Technology Commission of Shanghai Municipality (20520710400).

The high performance and safety of lithium-sulfur (Li-S) batteries are the focus of research in recent years. The separator is an important part of the battery, whose performance stability directly affects the performance of the battery. What’s more, there are still many defects in the commercial polyolefin separator. In this work, a polyethylene/polyetherimide (PE/PEI) composite separator is designed by surface coating and non-solvent-induced phase separation (NIPS) method. The film breakage temperature and anti-puncture strength of the PE/PEI composite separator (181.96 °C, 7.90 N) are higher than those of the commercial PE separator (153.00 °C, 6.20 N), which will greatly ensure the safety problems caused by internal self-heating and external short circuit of Li-S batteries. The PE/PEI composite separator–based Li-S battery delivers a high initial specific capacity of 1265 mAh g−1 at 0.2 C and exhibits excellent rate capability compared with the commercial PE separator. Therefore, the PE/PEI composite separator is a candidate separator for the high-performance and high-safety Li-S battery.

Significant improvement of lithium ion batteries (LIBs) performances has been achieved with a rapid advance of portable electronic devices over the past quarter century. With a growing demand for high performance power sources, world-wide efforts have been devoted to the development of an alternative battery system to replace current LIBs which face performance limitation in terms of capacity and energy density. Recently, lithium-sulfur (Li-S) batteries have received an unprecedented attention owing to their great potentials such as a large theoretical capacity of sulfur, low toxicity and low cost. As cutting-edge nanotechnologies (e.g., C-S composite concept, mesoporous interlayer) have been employed to Li-S batteries, their performances have been dramatically improved for the past two decades. Despite such remarkable progress, there have remained many issues (i.e., limited cycling performance and low rate properties) which should be addressed for successful commercialization of Li-S batteries. In addition, most approaches to solve those problems need so complex and expensive processes which are so hard to implement them to practical mass production. Herein, we report a facile and cost-effective approach for the development of high-performance Li-S batteries. Through combining a functional separator to a high-sulfur-loading cathode, which can mitigate the active material loss and confine polysulfide ions within a specific space ensuring a long cycle life, high-performance Li-S batteries are fabricated and their characteristic features are intensively investigated.

Simultaneous dual-defect engineering as a booster for polysulfide adsorption and conversion in Li-S battery

Engineering rare earth metal Ce-N coordination as catalyst for high redox kinetics in lithium-sulfur batteries

Lithium-sulfur (Li-S) batteries have been intensively investigated as a next-generation rechargeable battery due to their high energy density of 2600 W·h kg(-1) and low cost. However, the systemic issues of Li-S batteries, such as the polysulfide shuttling effect and low Coulombic efficiency, hinder the practical use in commercial rechargeable batteries. The introduction of a conductive interlayer between the sulfur cathode and separator is a promising approach that has shown the dramatic improvements in Li-S batteries. The previous interlayer work mainly focused on the physical confinement of polysulfides within the cathode part, without considering the further entrapment of the dissolved polysulfides. Here, we designed an ultrathin poly(acrylic acid) coated single-walled carbon nanotube (PAA-SWNT) film as a synergic functional interlayer to address the issues mentioned above. The designed interlayer not only lowers the charge transfer resistance by the support of the upper current collector but also localizes the dissolved polysulfides within the cathode part by the aid of a physical blocking and chemical bonding. With the synergic combination of PAA and SWNT, the sulfur cathode with a PAA-SWNT interlayer maintained higher capacity retention over 200 cycles and achieved better rate retention than the sulfur cathode with a SWNT interlayer. The proposed approach of combining a functional polymer and conductive support material can provide an optimiztic strategy to overcome the fundamental challenges underlying in Li-S batteries.

A multidimensional and nitrogen-doped graphene/hierarchical porous carbon as a sulfur scaffold for high performance lithium sulfur batteries

Donor dominated triazine-based microporous polymer as a polysulfide immobilizer and catalyst for high-performance lithium-sulfur batteries

An interwoven carbon nanotubes/cerium dioxide electrocatalyst accelerating the conversion kinetics of lithium sulfide toward high-performance lithium-sulfur batteries

Zn2+–Modulated bimetallic carbides synergized with macro-mesoporous N-rich carbon enabling accelerated polysulfides conversion for high-performance Li-S batteries

Fluoride-samarium(III) doped hierarchically porous carbon nanofibers as thin separator coating layer with excellent adsorption and outstanding catalysis of lithium polysulfide for lithium-sulfur batteries

Sulfur electrode tolerance and polysulfide conversion promoted by the supramolecular binder with rare-earth catalysis in lithium-sulfur batteries