Lithium Sulfur Research Articles

Engineering Oxygen Vacancies in In2O3 with Enhanced Polysulfides Immobilization and Selective Catalytic Capability.

Lithium-sulfur (Li-S) battery is identified as an ideal candidate for next-generation energy storage systems in consideration of its high theoretical energy density and abundant sulfur resources. However, the shuttling behavior of soluble polysulfides (LiPSs) and their sluggish reaction kinetics severely limit the practical application of the current Li-S battery. In this work, a series of In2O3 nanocubes with different oxygen vacancy concentrations are designed and prepared via a facile self-template method. The introduced oxygen vacancy on In2O3 can effectively rearrange the charge distribution and enhance sulfiphilic property. Moreover, the In2O3 with high oxygen vacancy concentration (H-In2O3) can slightly slow down the solid-liquid conversion process and significantly accelerate the liquid-solid conversion process, thus reducing the accumulation of LiPSs in electrolyte and inhibiting the shuttle effect. Contributed by the unique selective catalytic capability, the prepared H-In2O3 exhibits excellent electrochemical performance when used as sulfur host. For instance, a high reversible capacity of 609 mAh g-1 is obtained with only 0.044% capacity decay per cycle over 1000 cycles at 1.0C. This work presents a typical example for designing advanced sulfur hosts, which is crucial for the commercialization of Li-S battery.

Porous Organic Framework Materials (MOF, COF, and HOF) as the Multifunctional Separator for Rechargeable Lithium Metal Batteries.

The separator is an important component in batteries, with the primary function of separating the positive and negative electrodes and allowing the free passage of ions. Porous organic framework materials have a stable connection structure, large specific surface area, and ordered pores, which are natural places to store electrolytes. And these materials with specific functions can be designed according to the needs of researchers. The performance of porous organic framework-based separators used in rechargeable lithium metal batteries is much better than that of polyethylene/propylene separators. In this paper, thethree most classic organic framework materials (MOF, COF, and HOF) are analyzed and summarized. The applications of MOF, COF, and HOF separators in lithium-sulfur batteries, lithium metal anode, and solid electrolytes are reviewed. Meanwhile, the research progress of these three materials in different fields is discussed based on time. Finally, in the conclusion, the problems encountered by MOF, COF, and HOF in different fields as well as their future research priorities are presented. This review will provide theoretical guidance for the design of porous framework materials with specific functions and further stimulate researchers to conduct research on porous framework materials.

Cellulose-based separator woven by double-layer-configuration fibers for high S-load Li-S batteries

Lithium-sulfur (Li-S) battery with high theoretical energy density, has been the most promising next-generation energy storage devices. However, the capacity of the high S-loaded cathode decays rapidly due to the shuttling of soluble polysulfide intermediates between the two electrodes, which seriously inhibits its development. In this work, polyacrylonitrile (PAN) and cellulose composite film (PAN@CE) is designed, which is woven by double-layer configuration fiber. The outer layer of fiber is mainly composed of cellulose, and the inner layer is mainly PAN. From DFT calculations and experiments, the double-layer configuration enriched with nitrogen and oxygen groups can effectively inhibit the shuttle of soluble polysulfides. Meanwhile, the interlaced network structure of PAN@CE improves the electrolyte wettability and provides abundance transport paths for ions. In addition, the film also has good thermal stability. Hence, the cycling stability of Li-S batteries with PAN@CE as separator has been greatly improved. Cellulose-based Li-S battery with 9.1 mg S loading and an E/S ratio of 6.2 μL mg−1 is assembled. Its initial area capacity is 5.67 mAh cm−2. After 200 long cycles, the area capacity keeps above 4.0 mAh cm−2.

Balanced Mass Transfer and Active Sites Density in Hierarchical Porous Catalytic Metal–Organic Framework for Enhancing Redox Reaction in Lithium–Sulfur Batteries

Balanced Mass Transfer and Active Sites Density in Hierarchical Porous Catalytic Metal–Organic Framework for Enhancing Redox Reaction in Lithium–Sulfur Batteries

Covalent Organic Framework/Aluminum Oxide Composite Nanosheets as a Separator for High-Performance Lithium–Sulfur Batteries

Covalent Organic Framework/Aluminum Oxide Composite Nanosheets as a Separator for High-Performance Lithium–Sulfur Batteries

Three Birds with One Stone: Multifunctional Separators Based on SnSe Nanosheets Enable High‐Performance Li‐, Na‐ and K‐Sulfur Batteries

AbstractAlkali metal‐sulfur batteries (MSBs) are one of the most promising next‐generation energy storage technologies due to their high energy density and potential for low cost. They are nonetheless constrained by the sluggish conversion of metal polysulfides (MPS) during the charge/discharge process. Herein, a multifunctional separator able to trap the MPS and catalyze their conversion in the three main MSB chemistries, Li‐, Na‐, and K‐MSBs, is demonstrated. More in detail, SnSe nanosheets are introduced as additive into the cathode side of the glass microfiber (GF) separator of the MSB. Taking lithium‐sulfur batteries (LSBs) as an example, it is demonstrated that the GF‐SnSe separator (GF@SnSe) shows strong chemical affinity to lithium polysulfides (LiPS) and superior catalytic activity, inhibiting the transport of LiPSs to the anode and accelerating their conversion. Combining experimental and calculation results, the SnSe additive is shown to decrease the Li2S decomposition energy barrier. Overall, GF@SnSe separators provide significantly improved LSB rate performance and cycling stability with a 0.049% capacity decay per cycle. Besides, the GF@SnSe separator promotes the electrochemical performance of sodium‐sulfur and potassium‐sulfur batteries. Overall, this work presents a significant advancement in the development of multifunctional separators in LSBs as well as the emerging Na‐S and K‐S systems.

Electrochemical Restructuring Driven Catalytic Cycle of Bi-Based Heterojunctions for High-Performance Lithium-Sulfur Batteries.

Restructuring is an important phenomenon in catalytic reactions. Conversion-type materials with suitable redox potential may undergo in situ electrochemically driven restructurings and induce highly active catalytic sites in a working lithium-sulfur battery. Herein, driven by the electrochemical conversion reaction of BiVO4, a reversible catalytic cycle of Bi/amorphous Li3VO4 (a-Li3VO4) and Bi2S3/a-Li3VO4 heterojunctions is constructed, which targets the oxidation of Li2S and the conversion of polysulfide, respectively. The heterostructures and electrochemically driven size confinement provide abundant sites for shuttle restraining and sulfur conversion. Especially, the p-block Bi and Bi2S3 could dramatically reduce the conversion energy barriers of Li2S and polysulfide by virtue of the p-p orbital hybridization, promoting bidirectional reactions of the sulfur cathode. As a result, the corresponding sulfur cathode possesses a high reversible capacity of 7.5 mAh cm-2 after 120 cycles under a high sulfur loading of 10.3 mg cm-2 with a current density of 0.38 mA cm-2. This study furnishes a feasible scheme to obtain highly effective catalysts for bidirectional sulfur redox by utilizing the electrochemically induced restructuring.

ZIF-L/PBA-derived transition metal-based N-doped CNT modified membranes for lithium-sulfur batteries

The dual MOF framework ZIF-L/X-PBA (X = Fe, Co, and Ni) was formed by combining ZIF-L with Prussian blue (PBA), from which Fe3C-NCNT, Co-NCNT, and Ni-NCNT were derived. The effect of NCNT derived from different transition metals PBA on batteries performance was studied. Tests showed that the Li–S batteries using Fe3C-NCNT obtained an initial discharge capacity of 1456 mAh g−1 at 0.2 C, while the batteries using Co-NCNT and Ni-NCNT had inferior performance in all aspects compared to Fe3C-NCNT. It was found that Fe3C-NCNT had the best performance, and that the inhibitory effect of MOF derivatives on LiPS varied due to the different characteristics of the metal centers, but they all could suppress shuttle effect and extend the life of the batteries.

A Lithium‐Affinitive Covalent Organic Polymer Network Functionalized Separator for Dendrite‐Free and High‐Durability Lithium–Sulfur Batteries under Harsh Conditions

AbstractLithium–Sulfur (Li─S) batteries are renowned for their high theoretical specific capacity and cost‐effectiveness. Nevertheless, their performance could be impeded by obstacles including lithium dendrite growth and lithium polysulfide (LiPS) shuttle, particularly under harsh conditions. Herein, an economical strategy is reported for modifying polyolefin separators (PP) with covalent organic polymer networks (TPE) to alter Li solvent structure, enhance lithium‐ion transport, and suppress shuttle effects. Combining in situ/ex situ characterization and theoretical calculations, it is demonstrated that the lithiophilic groups (‐C═N‐) in the TPE@PP separator form strong interaction with lithium, facilitating the dissociation of Li─Solvent/LiPS‐solvent to release freer lithium ion and shape a stable solid electrolyte interface rich in LiF and Li3N. The polymer network serves as a “highway” that accelerates Li transport and promotes uniform nucleation behavior. Therefore, the Li|TPE@PP|CNT/S cell enables 60% capacity retention after 2000 cycles at 1.0 C and exhibits stable cycling performance of 100 cycles from ‐40 to 80 °C. Moreover, the pouch cell maintains a capacity of more than 600 mA h g−1 after 30 cycles at 0 °C. This study provides a promising avenue for the application of high‐performance batteries in harsh environment from the perspective of separator engineering.

Applying different nanomaterials to improve the performance of lithium-ion batteries

Due to their superior qualities, lithium-ion batteries (LIBs) have lately taken the top spot among rechargeable secondary batteries. To achieve the increasing demand for electricity in the related industries, its improvement and development are in full swing, especially the nanomaterials have become an important direction of improvement because of their special structure matching with charging-discharging mechanisms. This paper focuses on the application of nanomaterials in the LIBs. It briefly introduces carbon-based and silicon-based nanomaterials, metal (alloy), metal oxide (sulfide), MOFs nanomaterials, and Mxenes in lithium-ion batteries and lithium-sulfur batteries by reviewing the pertinent literature from recent years. including the reasons for their application, the application mechanism and the effectiveness of their improvement. It has been discovered that nanoparticles have numerous and intricate uses in the LIBs. It is hoped that this study can provide new ideas for the structural design and functional modification of nanomaterials in battery applications in the future.

Polyaniline-Coated Cobalt–Iron Oxide Composites Modified Separator for High Performance Lithium–Sulfur Batteries

Polyaniline-Coated Cobalt–Iron Oxide Composites Modified Separator for High Performance Lithium–Sulfur Batteries

SPAN secondary particles enabled high energy density Lithium-Sulfur battery

High-areal-capacity electrodes and lean electrolyte are practical approaches for batteries to enhance their energy density, while it’s challenge for the lithium-sulfur batteries using nano-sized sulfurized polyacrylonitrile (SPAN) cathodes due to the sluggish charge transportation. Here, a spray-drying (SD) technique for mass production of micron-sized SPAN secondary particles (PC-SPAN) with composite coating is proposed. The composite involves polydopamine (PDA), polyacrylic acid (PAA) and polyvinyl alcohol (PVA) that physiochemically crosslinking. The rich catecholamine, hydroxyl and carboxyl groups not only construct strong and flexible adhesion among the SPAN primary particles to keep the electrode integrity, but also render built-in ion passage within the secondary particles to allow the electrode working under lean electrolyte condition. Consequently, PC-SPAN electrode with a high areal loading of 8.4 mg cm−2 delivers a higher specific capacity of 547.4 mAh g−1 at 0.3C when that of SPAN is less than 400.0 mAh g−1. In the meantime, prototype Li-SPAN battery with high energy density of 530.2 Wh kg−1 is achieved using PC-SPAN electrode with an areal capacity of 19.1 mAh cm−2 and low electrolyte/SPAN ratio of 0.93 μL mg−1, which demonstrates the feasibility of this strategy toward applicable high energy LSBs.

Flower-like covalent organic frameworks as host materials for high-performance lithium-sulfur batteries

Lithium-sulfur (Li-S) batteries have emerged as a promising alternative energy storage system due to their high energy density and cost-effectiveness. However, practical applications of Li-S batteries are hindered by challenges such as the shuttle effect and sluggish redox kinetics. In this study, a three-dimensional (3D) flower-like diaminoanthraquinone (DAAQ)-covalent organic framework (COF) was developed, featuring nanorod-like petals and enriched with abundant N and O adsorption sites, serving as a host material for the sulfur cathode of Li-S batteries. Through a process of sulfur melting-diffusion, the resulting DAAQ-COF@S cathode material demonstrated a stable 3D cross-linked morphology with a hierarchical pore structure, maximizing the exposure of N/O adsorptive sites and facilitating rapid ion diffusion. This effectively inhibited the shuttling effect of lithium polysulfides (LiPSs) and enhanced rate performance. Consequently, DAAQ-COF@S cathodes exhibited a high initial discharge capacity of 1182.0 mAh g−1 at 0.1 C, with a capacity retention rate of 79.6% after 500 cycles at 2 C. Even at a high current density of 4 C, they maintained a high capacity of 616.8 mAh g−1, surpassing the majority of previously reported COF-based host materials for Li-S batteries. This work underscores the significance of COF micromorphology and advances the development of high-performance cathodes for Li-S batteries.

In Situ Constructing a TiO2/TiN Heterostructure Modified Carbon Interlayer for Balancing the Surface Adsorption and Conversion of Polysulfides in Li–S Batteries

AbstractSevere shuttle effect and sluggish reaction kinetics caused by lithium‐polysulfides have always been the dominant factor to reduce the actual energy density of lithium–sulfur batteries. It's very important to simultaneously balance the surface adsorption and redox conversion of the lithium‐polysulfides. Herein, a TiO2/TiN heterostructure and in situ N‐doping modified multifunctional carbon interlayer is designed and constructed using a melamine foam as the matrix material at a relatively low temperature and without NH3 atmosphere. Interestingly, TiO2 nano‐particles decorated on the N‐enriched melamine carbon foam can be partially in situ transformed into TiN during pyrolysis process. Based on the support of highly conductive and interconnected carbon skeletons, the N heteroatom and TiO2/TiN show good synergetic adsorption and conversion of the soluble lithium‐polysulfides, whilst boosting the electrochemical performance of lithium–sulfur batteries. Consequently, when used the multifunctional carbon interlayer, the Super P/sulfur cathode based lithium–sulfur battery delivers a high initial discharge capacity of 814 mAh g−1 at a high current rate of 2.0 C and maintain the 548 mAh g−1 after 500 cycles. Even with the high sulfur loading of 7.5 mg cm−2 and low E/S ratio of 4.7 µL mg−1, an acceptable areal capacity of 8.2 mAh cm−2 can be obtained.

In Situ Encapsulation of Cobalt Selenide Nanoparticles in N-Doped Carbon Nanotubes with a Full Sulfiphilic Surface as a Catalytic Interlayer for Lithium–Sulfur Batteries

In Situ Encapsulation of Cobalt Selenide Nanoparticles in N-Doped Carbon Nanotubes with a Full Sulfiphilic Surface as a Catalytic Interlayer for Lithium–Sulfur Batteries

Multi-heterostructured MXene/NiS2/Co3S4 with S-Vacancies to Promote Polysulfide Conversion in Lithium-Sulfur Batteries.

The severe shuttle effect of polysulfides (LiPSs) and the slow liquid-solid phase conversion are the main obstacles hindering the practical application of lithium-sulfur (Li-S) batteries. Separator modification with a high-activity catalyst can boost LiPSs conversion and suppress their shuttle effect. In this work, multi-heterostructured MXene/NiS2/Co3S4 with rich S-vacancies was constructed facilely with a hydrothermal and high-temperature annealing strategy for separator modification. The MXene sheet not only provides a physical barrier but also ensures a high conductivity and adsorption capacity of the catalyst; the dual active centers of NiS2 and Co3S4 catalyze LiPSs conversion. In addition, the vacancies and heterostructures can modulate the electronic structure of the catalyst, improve its intrinsic activity, and reduce the polysulfides reaction barrier, thus facilitating ion/electron transport and inhibiting the shuttle effect. Benefiting from these advantages, the Li-S battery with MXene/NiS2/Co3S4 modified separator exhibits exciting discharge capacities (1495.4 mAh g-1 at 0.1C and 549.0 mAh g-1 at 6C) and an excellent ultra-long cycle life (average capacity decay rate of 0.026% for 2000 cycles at 2C); at a high sulfur loading of 10.0 mg cm-2, the battery operates for nearly 80 cycles at 0.2C, giving a capacity retention rate of 75.76%. This work provides a high-activity catalyst for Li-S batteries.

Negatively charged hydrochar from Aesculus indica waste: A sustainable material for enhanced Li-S batteries performance

This study presents a negatively charged hydrochar from Aesculus indica waste, employing a microwave-assisted hydrothermal carbonization (HTC) method at very low temperatures (120∼200 °C). The research shows the utilization of these negatively-charged-oxygen-containing hydrochars in lithium-sulfur (Li-S) batteries effectively mitigates polysulfide shuttling through electrostatic repulsive forces and simultaneously facilitate uniform lithium-ion transportation, leading to substantial improvement in battery performance. Through detailed investigations into the HTC reaction mechanism, the concentration of the negatively charged oxygen functional groups is tunable by controlling the carbonization process, which could further improve the enhancement effects. Furthermore, negatively-charged-oxygen-containing hydrochars were utilized as modified separator in Li-S batteries to enhance the electrochemical performance. The batteries assembled with hydrochar modified separator, has an initial discharge capacity of 1216 mAh g−1 at 0.1 C, and after 200 cycles at 1 C, its reversible discharge capacity was still 800 mAh g−1 with more than 80 % capacity retention. This research not only provides an efficient method for the utilization of waste biomass, but also offers a new approach for the preparation of negatively charged carbon for lithium-sulfur batteries.

Review on performance optimization of Lithium Sulphur Batteries (LiSBs) using carbon based electrodes

Presently, researchers’ and experts are currently dealing with ways to maintain and improve the best performance of several energy storage technologies. This review focuses on how adding carbon derivatives to lithium sulfur battery (LiSBs) electrodes can reduce capacity fade, resistance, breakdown and poor performance while also enabling the best possible use of LiSBs in a variety of devices. Their rate as regards specific capacitance, energy and power densities, life duration, lightweight, etc., are among these optimal performances. The global energy crisis focused more scientists’ attention on how to enhance the performance of LiSBs devices for the benefit of humanity. Numerous carbon derivatives, including GO, rGO, carbon nanotubes (CNTs), etc., have advantageous properties that raise the efficiency of energy storage technologies. This review looked at LiSBs and the impact of carbon derivatives addition on their storage capability, cycle stability, life span and durability.

N-doped vanadium pentoxide materials for inhibiting shuttle effect in lithium-sulfur batteries

N-doped vanadium pentoxide materials for inhibiting shuttle effect in lithium-sulfur batteries

Consistent behaviors of KI in heat, light and electric fields towards the inversely vulcanized dicyclopentadiene cathode for lithium-sulfur batteries

The sulfured dicyclopentadiene (S-DCPD) is a promising cathode candidate for Li-S batteries. Enlightened by the function of KI in dye-sensitized solar cells, we employ KI as a catalyst in the preparation of S-DCPD without eliminating it in the assembly of Li-S batteries. As a result, the sulfurizing reaction proceeds more completely at a lower temperature. The as-prepared material exhibits a different light response to the blank sample, changing from a higher energy level to a lower one. And the electrochemistry is greatly elevated as well. Theoretical calculations validate that KI plays the key role by altering the electron transmitting path. We can thus unify the behaviors of KI in the field of heat, light, and electricity, phenomenally. Furthermore, we investigate the morphology changes of the electrode by dipping it in an ordinary solution and subjecting it to a cycle calendar life in the electrolyte, respectively. As a result, we make clear that the difference of the behaviors between ordinary solutions and electrolytes is also in associated with the electronic path of KI.