Performance Of Li-S Batteries Research Articles

Natural hematite-derived NiFe2O4 as a separator modification material for improved Li-S battery performance.

The shuttling effect of polysulfides in lithium-sulfur batteries seriously affects their performance. Herein, NiFe2O4 derived from natural hematite is coated on a PP separator (NFO@PP), which can effectively block the shuttling of polysulfides and has strong adsorption and catalytic capabilities. The NFO@PP cell has an initial capacity of up to 1258.1 mA h g-1 at 0.1C and still has 809.6 mA h g-1 at 2C. Impressively, at 0.5C, the NFO@PP cell retains a specific capacity of 612.1 mA h g-1 after 1000 cycles. The successful application of abundant natural hematite in lithium-sulfur batteries will certainly be of great significance to the development of more cost-effective energy storage devices.

Enhancing Li-S Battery Performance with Porous Carbon from Hanji

Hanji-derived porous carbon has been developed and utilized as a cathode material for Li-S batteries, demonstrating exceptional electrochemical performance and stability. The unique porous structure and high surface area of Hanji-based carbon enhanced S utilization and significantly improved the overall efficiency of the battery. The material exhibited excellent electrical conductivity and structural stability, effectively addressing the major challenges of Li-S batteries, such as the polysulfide shuttle effect and active material loss. In addition, flake carbon-coated separators (FCCSs) were integrated into Li-S cells to further enhance their performance, achieving a high initial specific capacity of approximately 1200 mAh/g and maintaining a capacity of 620 mAh/g after 100 cycles. In contrast, cells with conventional polypropylene separators exhibited lower initial capacities (946 mAh/g), which decreased to 366 mAh/g after 100 cycles. FCCSs also demonstrated superior capacity retention and stability under varying charge–discharge rates, maintaining a capacity of 200 mAh/g at 3 C and recovering to 730 mAh/g when the rate was 0.1 C. This study provides valuable insights into the development of sustainable and efficient Li-S battery systems, with Hanji-based carbon and FCCSs emerging as promising components for commercial applications.

Rationally Designed Cyclic Sulfonamide-Based Electrolyte for Improved Electrochemical Performance for Rechargeable Li Batteries

Electrolyte instability poses a significant challenge in stabilizing the interfacial chemistry of rechargeable batteries. The engineering of electrolyte architecture has emerged as a promising strategy to enhance electrode compatibility and interfacial stability. In this study, we present the synthesis of a rationally designed cyclic sulfonamide electrolyte tailored to improve the electrochemical performance of Anodeless Li metal batteries and Li-S batteries. This electrolyte is meticulously crafted to optimize crucial electrochemical properties, including Li ion transport, stability, and interface compatibility. Through systematic investigation, we illustrate that the incorporation of cyclic sulfonamide moieties leads to enhanced electrolyte stability, thereby mitigating detrimental side reactions and improving the cycling performance of Li metal batteries. Notably, the use of cyclic sulfonamide electrolyte prevents corrosion of the aluminum current collector caused by TFSI anion, which is commonly associated with the use of LiTFSI salt in commercial batteries, thus facilitating safe battery recycling. Additionally, the cyclic sulfonamide-based electrolyte effectively inhibits the polysulfide shuttle in Li-S batteries, achieving a remarkable coulombic efficiency exceeding 99.5% in the absence of LiNO3 additive. Furthermore, these engineered electrolytes demonstrate exceptional compatibility with Li metal anodes, promoting uniform Li deposition and suppressing dendrite formation, thereby enhancing battery safety and longevity. Our findings underscore the importance of rational electrolyte design in driving the advancement of Anodeless Li metal and Li-S batteries, offering a promising avenue for the realization of high-energy-density and durable energy storage solutions across diverse applications.

Interfacial Engineering of Polymer Solid-State Lithium Battery Electrolytes and Li-Metal Anode: Current Status and Future Directions.

A combination of material innovations, advanced manufacturing, battery management systems, and regulatory standards is necessary to improve the energy density and safety of lithium (Li) batteries. High-energy-density solid-state Li-batteries have the potential to revolutionize industries and technologies, making them a research priority. The combination of improved safety and compatibility with high-capacity electrode materials makes solid-stateLi-batteries with polymer solid-electrolytes an attractive option for applications where energy density and safety are critical. While polymer-based solid-state Li-batteries hold enormous promise, there are still several challenges that must be addressed, particularly regarding interface between polymer solid-electrolyte and Lianode. There are significant advancements in improving the performance of solid-state Li batteries, and researchers continue to explore new methods to address these challenges. These improvements are critical for enabling the widespread adoption of solid-state Li-batteries invariety of applications, from electrical vehicles to portable electronics. Here, common polymer solid-electrolyte and its interface challenges with Lianode are first introduced, highlighting the trend in polymer solid-state-electrolyte research toward enhancing stability, safety, and performance of solid-state Li-batteries. This includes developing novel polymer materials with improved properties, exploring advanced fabrication techniques, and integrating these electrolytes into battery designs that optimize both safety and energy density.

Doped germanene as anchoring material for lithium polysulfides for Li-S batteries: A DFT study

Lithium-sulfur batteries face significant challenges due to the dissolution of lithium polysulfides (LiPSs), commonly known as the shuttle effect, which leads to a loss in charge capacity. This study uses density functional theory (DFT) calculations, with van der Waals corrections, to investigate the polysulfide anchoring potential of a boron-doped germanene monolayer (B-2DGe). The results show that the adsorption energies of LiPSs on B-2DGe range from 1.46 to 3.39 eV. Furthermore, all LiPSs on B-2DGe exhibit conductive behavior. These findings suggest that B-2DGe, as a LiPS substrate, reduces the shuttle effect and prevents polysulfide agglomeration at electrodes, improving the performance of Li-S batteries.

Nitrogen-Doped Carbon and Metal-Nitrogen-Carbon Materials as Cathode Hosts for Li-S Batteries: Experimental Study and Mechanism Analysis.

Both nitrogen-doped carbon (NC) and metal-nitrogen-carbon (MNC) materials have been extensively investigated in lithium-sulfur batteries to alleviate the "shuttle effect". MNC are generally synthesized using NC as the parent material, wherein nitrogen atoms in NC serve as the "bridge" to coordinate with metal atoms. So far, an important scientific issue has not been settled: does the introduction of metal sites into NC certainly enhance the Li-S battery performance? In this work, NC and MNC materials derived from the same precursor, a nitrogen-rich porous polymer, are systematically compared as cathode hosts for Li-S battery through theoretical calculations and experimental investigation. Li-S cell with NC as the cathode sulfur host exhibits better cycle performance at low current densities (0.1 and 0.2C), whereas MNC materials predominate at higher current densities (such as 1C and 2C). Based on theoretical calculation and experimental results, it is concluded that the introduction of metal sites into NC through nitrogen bonding promoted the catalytic capability for faster sulfur redox reaction kinetics, whereas the adsorption energy toward polysulfides decreased. This work provides important guidance for more targeted design of advanced materials for lithium-sulfur battery application in the future.

Study of the Activator Effects on the Specific Surface Area of Porous Carbon and its Performance as Lithium-Sulfur Battery Cathode

A study was conducted to investigate the effect of activator types KOH, ZnCl2, and H3PO4 on the specific surface area of porous carbon and its performance as a Li-S battery. Porous carbon was synthesized from candlenut shells through a carbonization process at 700 °C using three types of activator solutions with a concentration of 0.36 M. The porous carbon activated with KOH achieved the best results, with a specific surface area of 681 m²g-1. The porous carbon candlenut shell-sulfur (PCCS-S) composite was obtained by the solid-state reaction method in a ratio of 1:2.5 w% and heat-treated at 155 °C to form the PCCS-S composite. The PCCS-S composite was then made into a slurry and coated onto Al-foil to obtain a layer of electrodes with a thickness of 200 µm. The PCCS-S cathode was then assembled into a coin battery with lithium metal as the anode and an electrolyte of 1.0 M LiTFSi solution dissolved in 1,3-dioxolane (DOL) and 1,2-dimethoxyethane (DME) (v/v, 1:1). Charge-discharge characterization was carried out at a charge rate of 1 C for 50 cycles. Characterization shows that the performance of the PCCS-S KOH composite cathode Li-S battery is stable at a specific capacity of 324 mAhg-1 after the first 10 cycles, with an average Coulombic efficiency of around 86.8 %.

A Review on Architecting Rationally Designed Metal-Organic Frameworks for the Next-Generation Li-S Batteries.

The modern era demands the development of energy storage devices with high energy density and power density. There is no doubt that lithium‒sulfur batteries (Li‒S) claim high theoretical energy density and have attracted great attention from researchers, but fundamental exploration and practical applications cannot converge to utilize their maximum potential. The design parameters of Li-S batteries involve various complex mechanisms, and their obliviousness has resulted in failure at the commercial level. This article presents a review on rationally designed metal-organic frameworks (MOFs) for improving next-generation Li-S batteries. The use of MOFs in Li-S batteries is of great interest because of their large surface area, porous structure, and selective permeability for ions. The working principles of Li-S batteries, the commercialization of Li-S batteries, and the use of MOFs as electrodes, electrolytes, and separators are critically examined. Finally, designed strategies (host structure, binder improvement, separator modification, lithium metal protection, and electrolyte optimization) are developed to increase the performance of Li-S batteries.

Widening the Operational Temperature Range of Lithium Batteries Using Flame-Retardant Sulfone-Based Highly Concentrated Electrolytes

High-concentration Li salt/sulfone solutions have attracted attention as promising liquid electrolytes for Li batteries owing to their high oxidative stability, nonflammability, and high Li+ ion transference number (t Li+). Herein, we report the temperature-dependent electrolyte properties of a sulfone-based ternary mixture composed of LiN(SO2F)2, sulfolane, and dimethyl sulfone, which enables Li batteries to operate in a wide temperature range. At −20 °C, the rate capability of a Li/LiCoO2 cell with the sulfone-based electrolyte was comparable to that with a conventional carbonate-based electrolyte, even though the ionic conductivity of the electrolyte was significantly lower in the former case (0.11 versus 2.92 mS cm−1). This is because the former electrolyte has a higher t Li+ value, effectively suppressing the concentration overpotential during cell charging and discharging. Moreover, the vapor pressure was much lower for the sulfone-based electrolyte than for the carbonate-based one, and the Li/LiCoO2 cell with the former electrolyte was successfully operated at 60 °C. This study provides insights into the characteristics of high-concentration electrolytes that affect the temperature dependence of Li battery performance.

Ultra-Low Alginate-Based Multifunctional Composite Binders for Enhanced Mechanical, Electrochemical, and Thermal Performance of Li-S Batteries.

The practical application of Li-S batteries, which hold great potential as energy storage devices, is impeded by various challenges, such as capacity degradation caused volume change, polysulfide shuttling, poor electrode kinetics, and safety concerns. Binder plays a crucial role in suppressing volume change of cathode side, thereby enhancing the electrochemical performance of Li-S batteries. In this research, a novel network binder (SA-Co-PEDOT) composed of sodium alginate is presented, Co2+ ions as cross-linking agent and PEDOT as an electronic conductor. The theoretical analysis and experimental testing confirm that the SA-Co-PEDOT binder with synergistic combination of catalytic center and electron transfer network effectively mitigates large volumetric changes during cycling while simultaneously enhancing electrode kinetics through controlling the deposition morphology of sulfur end product and its nucleation and dissolution. As a result, it achieves a capacity of 844 mAh g-1 after 150 cycles at 0.2 C. Moreover, the electrode with SA-Co-PEDOT binder subjected a bending test maintains a capacity of 395 mAh g-1 after 500 cycles at 0.5 C, exhibiting an impressively low decay rate of only 0.11%. Even with an ultra-low content of 2 wt.% SA-Co-PEDOT binder, the electrode still maintains a capacity of 999.7 mAh g-1 after 100 cycles at 0.5 C.

Kinetics enhancement of an advanced separator modified by vanadium-based MXene for Li-S batteries

Li-S batteries are promising because of the ultrahigh theoretical energy density (2600 Wh kg−1), however the severe shuttle effect of polysulfides and hysteresis of reaction kinetics hinder the application of Li-S batteries. Hence, this work raises a vanadium-based MXene modified separator for Li-S batteries, which can effectively inhibit the irreversible loss of polysulfides and further accelerate their rapid conversion. In addition, the kinetic enhancement role of this functionalized separator is studied from the electrochemistry perspective. As expected, both the cyclic stability and rate performance of Li-S batteries with this advanced separator are significantly improved, which highlight the application prospect in the field of energy storage and conversion.

Coordination Engineering of Fe-Centered Catalysts for Superior Li-S Battery Performance.

Iron-nitrogen functionalized graphene has emerged as a promising cathode host for rechargeable lithium-sulfur batteries (RLSBs) due to its affordability and enhanced battery performance. To optimize its catalytical efficiency, we propose a novel approach involving coordination engineering. Our investigation spans a plethora of catalysts with varied coordination environments, focusing on elements B, C, N and O. We revealed that Fe-C4 and Fe-B2C2-h are particularly effective for promoting Li2S oxidation, whereas Fe-N4 excels in catalyzing the sulfur reduction reaction (SRR). Importantly, our study identified specific descriptors - namely, the Integrated Crystal Orbital Hamilton Population (ICOHP) and the bond length between Fe and S in Li2S adsorbed state - as the most effective predictive descriptors for Li2S oxidation barriers. Meanwhile, Li2S adsorption energy emerges as a reliable descriptor for assessing the SRR barrier. These identified descriptors are expected to be instrumental in rapidly identifying promising cathode hosts across various metal-centered systems with diverse coordination environments. Our findings not only offer valuable insights into the role of coordination environment, but also present an effective path for rapidly identifying high performance catalysts for RLSBs, enabling the acceleration of advanced RLSBs development.

Synergistic Effect of Lactam and Pyridine Nitrogen on Polysulfide Chemisorption and Electrocatalysis in Lithium Sulfur Batteries.

Sulfur undergoes various changes, including the formation of negative charge-bearing lithium polysulfides during the operation of Li-S batteries. Dissolution of some of the polysulfides in battery electrolytes is one of the reasons for the poor performance of Li-S batteries. The charge injection into the sulfur and polysulfides from the electrode is also a problem. To address these issues, a small-molecule additive, 3,6-di(pyridin-4-yl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione, was designed and synthesized with carbonyl oxygen atoms and two types of nitrogen. The pyridinic nitrogen increases the electronegativity of the carbonyl oxygen atoms. The pyridinic nitrogen, carbonyl oxygen, and lactam nitrogen provide multiple binding sites concurrently to the polysulfides, which increases the binding efficiency between the additive and polysulfides. A control molecule without the pyridine moiety displayed decreased binding to lithium polysulfides. Furthermore, the band edges of lithium polysulfide and 3,6-di(pyridin-4-yl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione are commensurate for efficient charge transfer between them, leading to the efficient electrocatalysis of lithium polysulfides. The cyclic voltammogram of the Li-S battery fabricated with 3,6-di(pyridin-4-yl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione exhibited sharp and well-defined peaks, confirming the formation of Li2Sy (where y varies between one and eight) from S8. These Li-S batteries showed a specific capacity of 950 mA h/g at 0.5 C, with a capacity retention of 70% at the 300th cycle. The pyridine-free control molecule, 3,6-diphenyl-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione, showed relatively poor performance in a Li-S battery.

Sulfur-containing polymers for enhancing rate and cycle performance of lithium-sulfur batteries

Sulfur-containing polymer with covalent C-S bonds has become an ideal alternative cathode of element sulfur for lithium-sulfur battery. However, the rational design of polymer structure with high sulfur content and enhanced electrochemical performance of Li-S battery is still a great challenge. In this study, a facial synthesis of sulfur-containing polymer by using 1,2,3-trichloropropane and sulfur as starting materials at a mild condition was reported, and the covalent anchoring of the C-S bonds within the polymer effectively inhibited the shuttle effect of polysulfides, providing a splendid internal environment for the diffusion of lithium ions. As a result, the rich sulfur content (higher than 80 %) and its homogeneous distribution in the polymer backbone determined the excellent rate performance of obtained sulfur-containing polymers. In terms of cycling performance, the reversible specific capacity of the battery is 396 mAh/g after 500 cycles at a current density of 0.5 A/g and 350 mAh/g after 800 cycles at 1 A/g, with a capacity decay of only 0.06 % per cycle.

Engineering d-p Orbital Hybridization with P, S Co-Coordination Asymmetric Configuration of Single Atoms Toward High-Rate and Long-Cycling Lithium-Sulfur Battery.

Single-atom catalysts (SACs) have been increasingly explored in lithium-sulfur (Li-S) batteries to address the issues of severe polysulfide shuttle effects and sluggish redox kinetics. However, the structure-activity relationship between single-atom coordination structures and the performance of Li-Sbatteries remain unclear. In this study, a P, S co-coordination asymmetric configuration of single atoms is designed to enhance the catalytic activity of Co central atoms and promote d-p orbital hybridization between Co and S atoms, thereby limiting polysulfides and accelerating the bidirectional redox process of sulfur. The well-designed SACs enable Li-S batteries to demonstrate an ultralow capacity fading rate of 0.027% per cycle after 2000 cycles at a high rate of 5 C. Furthermore, they display excellent rate performance with a capacity of 619 mAh g-1 at an ultrahigh rate of 10 C due to the efficient catalysis of CoSA-N3PS. Importantly, the assembled pouch cell still retains a high discharge capacity of 660 mAh g-1 after 100 cycles at 0.2 C and provides a high areal capacity of 4.4 mAh cm-2 even with a high sulfur loading of 6mg cm-2. This work demonstrates that regulating the coordination environment of SACs is of great significance for achieving state-of-the-art Li-S batteries.

Densely Branched Carbon Nanotubes for Boosting the Electrochemical Performance of Li-S Batteries.

To address the inherent limitations of conventional carbon nanotubes (CNTs), such as their tendency to agglomerate and scarcity of catalytic sites, the development of branched carbon nanotubes (BCNTs) with a unique hierarchical structure has emerged as a promising solution. Herein, gram scale quantities of densely branched and structurally consistent Ni-Fe decorated branched CNTs (Ni-Fe@BCNT) have been prepared. This uniform and densely branched architecture ensures excellent dispersibility and superior electrical conductivity. Additionally, each branched tip is equipped with Ni-Fe particles, thereby providing numerous catalytic sites which endow them with exceptional catalytic activity for the conversion of polysulfides. The polypropylene (PP) separator modified with Ni-Fe@BCNT interlayer is fabricated as a multifunctional barrier for Li-S batteries. The experimental results demonstrate that Ni-Fe@BCNT interlayer can effectively suppress the shuttle effect of polysulfides and enhance their redox kinetics. The outstanding catalytic ability of Ni-Fe@BCNT interlayer enables batteries with high specific capacities, outstanding rate performance, and remarkable cycling stability. This approach proposed in this work paves a new path for synthesizing BCNTs and shows great potential for scaling up the production of BCNTs to address more demanding applications.

High-performance Li[sbnd]S battery separators based on F-element doped loofah sponge biomass carbon materials

Lithium-sulfur batteries are a new high-performance battery technology that consists of lithium metal as the negative electrode and sulfide material as the positive electrode. Compared with conventional lithium-ion batteries, LiS batteries offer higher energy density as well as cost advantages. However, the shuttle effect of polysulfides in LiS batteries can lead to serious degradation of cycling performance, etc., which hinders the commercialization of LiS batteries. For this reason, in this study, the green biomass material loofah sponge was used as a precursor, and the porous carbon material was produced by calcination after introducing the F element and used as a separator modifier to curb the shuttle effect, which is environmentally friendly, economical, and green. Comparative studies were conducted on ordinary PP separators, separators made of carbon materials before and after F-doping. The experimental results show that the F-doped porous carbon material cladding membrane improves the charge/discharge capacity, multiplication performance, and cycle stability of LiS batteries, which reflects the great potential in practical applications.

Nanostructured S@VACNTs Cathode with Lithium Sulfate Barrier Layer for Exceptionally Stable Cycling in Lithium-Sulfur Batteries

Lithium-sulfur technology garners significant interest due to sulfur’s higher specific capacity, cost-effectiveness, and environmentally friendly aspects. However, sulfur’s insulating nature and poor cycle life hinder practical application. To address this, a simple modification to the traditional sulfur electrode configuration is implemented, aiming to achieve high capacity, long cycle life, and rapid charge rates. Binder-free sulfur cathode materials are developed using vertically aligned carbon nanotubes (CNTs) decorated with sulfur and a lithium sulfate barrier layer. The aligned CNT framework provides high conductivity for electron transportation and short lithium-ion pathways. Simultaneously, the sulfate barrier layer significantly suppresses the shuttle of polysulfides. The S@VACNTs with Li2SO4 coating exhibit an extremely stable reversible areal capacity of 0.9 mAh cm−2 after 1600 cycles at 1 C with a capacity retention of 80% after 1200 cycles, over three times higher than lithium iron phosphate cathodes cycled at the same rate. Considering safety concerns related to the formation of lithium dendrite, a full cell Si-Li-S is assembled, displaying good electrochemical performances for up to 100 cycles. The combination of advanced electrode architecture using 1D conductive scaffold with high-specific-capacity active material and the implementation of a novel strategy to suppress polysulfides drastically improves the stability and the performance of Li-S batteries.

Electronic Spin Alignment within Homologous NiS2/NiSe2 Heterostructures to Promote Sulfur Redox Kinetics in Lithium-Sulfur Batteries.

The catalytic activation of the Li-S reaction is fundamental to maximize the capacity and stability of Li-S batteries (LSBs). Current research on Li-S catalysts mainly focuses on optimizing the energy levels to promote adsorption and catalytic conversion, while frequently overlooking the electronic spin state influence on charge transfer and orbital interactions. Here, hollow NiS2/NiSe2 heterostructures encapsulated in a nitrogen-doped carbon matrix (NiS2/NiSe2@NC) are synthesized and used as a catalytic additive in sulfur cathodes. The NiS2/NiSe2 heterostructure promotes the spin splitting of the 3d orbital, driving the Ni3+ transformation from low to high spin. This high spin configuration raises the electronic energy level and activates the electronic state. Thisaccelerates the charge transfer and optimizes the adsorption energy, lowering the reaction energy barrier of the polysulfidesconversion. Benefiting from these characteristics, LSBs based on NiS2/NiSe2@NC/S cathodes exhibit high initial capacity (1458 mAh·g⁻1 at 0.1C), excellent rate capability (572 mAh·g⁻1 at 5C), and stable cycling with an average capacity decay rate of only 0.025% per cycle at 1C during 500 cycles. Even at high sulfur loadings (6.2 mg·cm⁻2), high initial capacities of 1173 mAh·g⁻1 (7.27 mAh·cm⁻2) are measured at 0.1C, and 1058 mAh·g⁻1 is retained after 300 cycles.

In-situ constructing cathode protective film toward high performance of Li-S batteries at high sulfur loadings

Shuttle effect of lithium polysulfide (LiPSs) and low sulfur loadings encumber practical application of Li-S batteries. Sulfur cathode coating is a direct and effective strategy to alleviate the problem. However, it is difficult for the available ex-situ coating to suppress shuttle effect at high sulfur surface loading. In the present work, diphenylamine (DPA) is used as an electrolyte additive, which can undergo electropolymerization and form an in-situ PDPA film on sulfur cathode, thereby inhibiting LiPSs diffusion. More importantly, computations and experiments prove that DPA-LiPSs complexes are formed in the electrolyte, increasing the solubility of LiPSs and improving the conversion kinetics. Benefit from the above, the capacity of DPA battery reaches 1029.5 mAh g−1 with sulfur loading of 3 mg cm−2 at 1 C rate, and keeps 762.1 mAh g−1 after 1000 cycles. Excellent cycling performance is achieved even at a high sulfur loading of up to 7 mg cm−2. This work provides a new strategy for suppressing the LiPSs shuttle effect under high sulfur surface loadings.