首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Although batteries fitted with sodium metal anodes and sulfur cathodes are attractive for their higher energy density and lower cost, the threat of polysulfide migration in organic liquid electrolytes, uncontrollable dendrites, and corresponding safety issues has locked the deployment of the battery system. Introduction of solid-state electrolytes to replace conventional liquid-based electrolytes has been considered an effective approach to address these issues and further render solid-state sodium-sulfur battery (SSSSB) systems with higher safety and improved energy density. Nevertheless, the practical applications of SSSSB are still hampered by grand challenges, such as poor interfacial contact, sluggish redox kinetics of sulfur conversion, and Na dendrites. Currently, various strategies have been proposed and utilized to negate the problems within the solid-state battery. Herein, a timely and comprehensive review of emerging strategies to promote the development of SSSSB is presented. The critical challenges that prevent the real application of the SSSSB technique are analyzed initially. Subsequently, various strategies for boosting the development of SSSSB are comprehensively summarized, containing the developing of the advanced cathode and cathode/electrolyte interface, tailoring the solid electrolyte, and designing the stable anode and anode/electrolyte interface. Finally, further perspectives on stimulating the practical application of SSSSB technology are provided.  相似文献   

2.
Li‐S batteries can potentially deliver high energy density and power, but polysulfide shuttle and lithium dendrite formations on Li metal anode have been the major hurdle. The polysulfide shuttle becomes severe particularly when the areal loading of the active material (sulfur) is increased to deliver the high energy density and the charge/discharge current density is raised to deliver high power. This study reports a novel mechanochemical method to create trenches on the surface of carbon nanotubes (CNTs) in free‐standing 3D porous CNT sponges. Unique spiral trenches are created by pressures during the chemical treatment process, providing polysulfide‐philic surfaces for cathode and lithiophilic surfaces for anode. The Li‐S cells made from manufacturing‐friendly sulfur‐sandwiched cathodes and lithium‐infused anodes using the mechanochemically treated electrodes exhibit a strikingly high areal capacity as high as 13.3 mAh cm?2, which is only marginally reduced even with a tenfold increase in current density (16 mA cm?2), demonstrating both high “cell‐level” energy density and power. The outstanding performance can be attributed to the significantly improved reaction kinetics and lowered overpotentials coming from the reduced interfacial resistance and charge transfer resistance at both cathodes and anodes. The trench–wall CNT sponge simultaneously tackles the most critical problems on both the cathodes and anodes of Li‐S batteries, and this method can be utilized in designing new electrode materials for energy storage and beyond.  相似文献   

3.
The magnesium–sulfur (Mg-S) battery has attracted considerable attention as a candidate of post-lithium battery systems owing to its high volumetric energy density, safety, and cost effectiveness. However, the known shuttle effect of the soluble polysulfides during charge and discharge leads to a rapid capacity fade and hinders the realization of sulfur-based battery technology. Along with the approaches for cathode design and electrolyte formulation, functionalization of separators can be employed to suppress the polysulfide shuttle. In this study, a glass fiber separator coated with decavanadate-based polyoxometalate (POM) clusters/carbon composite is fabricated by electrospinning technique and its impacts on battery performance and suppression of polysulfide shuttling are investigated. Mg–S batteries with such coated separators and non-corrosive Mg[B(hfip)4]2 electrolyte show significantly enhanced reversible capacity and cycling stability. Functional modification of separator provides a promising approach for improving metal–sulfur batteries.  相似文献   

4.
Inspired by the first rechargeable Mg battery about 20 years ago, based on a Chevrel phase cathode, a Mg foil anode, and a magnesium organo‐aluminate electrolyte, research on rechargeable batteries using sulfur as the cathode together with Mg as the anode has gained substantial and increasing interest. In particular, the safety characteristics of magnesium–sulfur (Mg–S) batteries, the high abundance of both magnesium and sulfur, and the high theoretical volumetric energy density of magnesium render this system specifically interesting for mobile applications that require high volumetric energy densities, i.e., the automotive and aviation sector. While the development of Mg–S batteries is still at a nascent stage, some breakthroughs have already been accomplished. Consequently, it appears necessary to provide a comprehensive up‐to‐date review about the current achievements to facilitate further improvements in this field. In this review, the state of the art in Mg–S batteries is summarized, focusing on sulfur conversion cathodes, magnesium anode materials, currently employed electrolyte systems, as well as on current collectors and separator design. In addition, the challenges and some possible future work to realize a practically applicable and technically viable Mg–S battery are highlighted.  相似文献   

5.
To eliminate capacity‐fading effects due to the loss of sulfur cathode materials as a result of polysulfide dissolution in lithium–sulfur (Li–S) cells, 3D carbon aerogel (CA) materials with abundant narrow micropores can be utilized as an immobilizer host for sulfur impregnation. The effects of S incorporation on microstructure, surface area, pore size distribution, and pore volume of the S/CA hybrids are studied. The electrochemical performance of the S/CA hybrids is investigated using electrochemical impedance spectroscopy, galvanostatical charge–discharge, and cyclic voltammetry techniques. The 3D porous S/CA hybrids exhibit significantly improved reversible capacity, high‐rate capability, and excellent cycling performance as a cathode electrode for Li–S batteries. The S/CA hybrid with an optimal incorporating content of 27% S shows an excellent reversible capacity of 820 mAhg?1 after 50 cycles at a current density of 100 mAg?1. Even at a current density of 3.2C (5280 mAg?1), the reversible capacity of 27%S/CA hybrid can still maintain at 521 mAhg?1 after 50 cycles. This strategy for the S/CA hybrids as cathode materials to utilize the abundant micropores for sulfur immobilizers for sulfur impregnation for Li–S battery offers a new way to solve the long‐term reversibility obstacle and provides guidelines for designing cathode electrode architectures.  相似文献   

6.
The lithium–sulfur (Li–S) battery is regarded as the most promising rechargeable energy storage technology for the increasing applications of clean energy transportation systems due to its remarkable high theoretical energy density of 2.6 kWh kg?1, considerably outperforming today's lithium‐ion batteries. Additionally, the use of sulfur as active cathode material has the advantages of being inexpensive, environmentally benign, and naturally abundant. However, the insulating nature of sulfur, the fast capacity fading, and the short lifespan of Li–S batteries have been hampered their commercialization. In this paper, a functional mesoporous carbon‐coated separator is presented for improving the overall performance of Li–S batteries. A straightforward coating modification of the commercial polypropylene separator allows the integration of a conductive mesoporous carbon layer which offers a physical place to localize dissolved polysulfide intermediates and retain them as active material within the cathode side. Despite the use of a simple sulfur–carbon black mixture as cathode, the Li–S cell with a mesoporous carbon‐coated separator offers outstanding performance with an initial capacity of 1378 mAh g?1 at 0.2 C, and high reversible capacity of 723 mAh g?1, and degradation rate of only 0.081% per cycle, after 500 cycles at 0.5 C.  相似文献   

7.
Li–S batteries benefit from numerous advantages such as high theoretical capacity, high energy density, and availability of an abundance of sulfur. However, commercialization of Li–S batteries has been impeded because of low loading amount of active materials and poor cycle performance. Herein, a freestanding bilayer carbon–sulfur (FBCS) cathode is reported with superior electrochemical performance at a high sulfur loading level (3 mg cm?2). The top component of the FBCS cathode is composed of interlacing multiwalled carbon nanotubes (MWCNT) and the bottom component is made up of a mixed layer of sulfur imbedded in MWCNT and N‐doped porous carbon (NPC). The MWCNT layer (top part of FBCS cathode) blocks polysulfide migration from the cathode to the anode, and NPC in the bottom part of the FBCS cathode not only provides spacious active sites but also absorbs polysulfide by the nitrogen functional group. The designed novel FBCS cathode delivered a high initial discharge capacity of 964 and 900 mAh g?1 at 0.5 and 1 C, respectively. It also displayed an excellent capacity retention of 83.1% at 0.5 C and 83.4% at 1 C after 300 cycles.  相似文献   

8.
The rational design of electrocatalyst has readily stimulated a burgeoning interest in expediting polysulfide conversion and hence essentially restricting the “shuttle effect” in Li–S systems. Nevertheless, seldom efforts have been devoted to probing the dual-directional polysulfide electrocatalysis to date. Herein, a CoFe alloy decorated mesoporous carbon sphere (CoFe-MCS) serving as a promising mediator for Li–S batteries is reported. Such bimetallic alloying boosts dual-directional electrocatalytic activity toward effective polysulfide conversion throughout detailed electroanalytic characterization, theoretical calculation, and operando instrumental probing. Accordingly, the S@CoFe-MCS cathode harvests a stable cycling with a low capacity decay rate of 0.062% per cycle over 500 cycles at 2.0 C. More encouragingly, benefiting from the optimized redox kinetics and delicate grid architecture, printable S@CoFe-MCS cathode achieves an excellent rate performance at a sulfur loading of 4.0 mg cm−2 and advanced areal capacity of 6.0 mAh cm−2 at 7.7 mg cm−2. This work explores non-precious metal alloy electrocatalysts in printable cathodes toward dual-directional polysulfide conversion, holding great potential in the pursuit of Li–S commercialization.  相似文献   

9.
Rechargeable sodium–sulfur/selenium/iodine (Na–S/Se/I2) batteries are regarded as promising candidates for large-scale energy storage systems, with the advantages of high energy density, low cost, and environmental friendliness. However, the electrochemical performances of Na–S/Se/I2 batteries are still restricted by several inherent issues, including the “shuttle effect” of polysulfides/polyselenides/polyiodides (PSs/PSes/PIs), sluggish kinetics of the conversion reactions at the cathodes, and Na dendrite growth at the anodes. Among these challenges, uncontrolled “shuttle effect” of PSs/PSes/PIs is a major contributing factor for the irreversible loss of active cathode materials and severe side reactions on Na metal anodes, leading to rapid failure of the batteries. Separator modification has been demonstrated to be an effective strategy to suppress the shuttling of PSs/PSes/PIs. Herein, the latest achievement in modifying separators for high-performance Na–S/Se/I2 batteries is comprehensively reviewed. The reaction mechanisms of each battery system are first discussed. Then, strategies of separator modification based on the different functions for regulating the transportation of PSs/PSes/PIs are summarized, including applying electrostatic repulsive interaction, introducing conductive layers, improving sieving effects, enhancing chemisorption capability, and adding efficient electrocatalysts. Finally, future perspectives on the practical application of modified separators in high-energy rechargeable batteries are provided.  相似文献   

10.
The practical application of lithium‐sulfur (Li‐S) batteries remains remote because of rapid capacity fade caused by the low conductivity of sulfur, dissolution of intermediate lithium polysulfides, severe volumetric expansion, and slow redox kinetics of polysulfide intermediates. Here, to address these obstacles, a new sulfiphilic and highly conductive honeycomb‐like spherical cathode host constructed from hollow metallic and polar Co9S8 tubes is designed. Co9S8 can effectively bind polar polysulfides for prolonged cycle life, due to the strong chemisorptive capability for immobilizing the polysulfide species. The hollow structure, as the sulfur host, can further prevent polysulfide dissolution and offer sufficient space to accommodate the necessary volume expansion. Well‐aligned tubular arrays provide a conduit for rapid conduction of electrons and Li‐ions. More importantly, the experimental results and theoretical calculations show that Co9S8 plays an important catalytic role in improving the electrochemical reaction kinetics. When used as cathode materials for Li–S batteries, the S@Co9S8 composite cathode exhibits high capacity and an exceptional stable cycling life demonstrated by tests of 600 cycles at 1 C with a very low capacity decay rate of only ≈0.026% per cycle.  相似文献   

11.
A critical bottleneck that hinders major performance improvement in lithium‐ion and sodium‐ion batteries is the inferior electrochemical activity of their cathode materials. While significant research progresses have been made, conventional single‐phase cathodes are still limited by intrinsic deficiencies such as low reversible capacity, enormous initial capacity loss, rapid capacity decay, and poor rate capability. In the past decade, layer‐based heterostructured cathodes acquired by combining multiple crystalline phases have emerged as candidates with a huge potential to realize performance breakthrough. Herein, recent studies on the structural properties, electrochemical behaviors, and synthesis route optimizations of these heterostructured cathodes are summarized for in‐depth discussions. Particular attention is paid to the latest mechanism discoveries and performance achievements. This review thus aims to promote a deeper understanding of the correlation between the crystal structure of cathodes and their electrochemical behavior, and offers guidance to design advance cathode materials from the aspect of crystal structure engineering.  相似文献   

12.
A one‐pot synthesis of three‐dimensional carbon nanotube frameworks with bipyramidal sulfur particles and the application of these materials for a cathode in lithium–sulfur (Li–S) battery are reported. By simple mixing of multi‐walled carbon nanotubes (MWCNTs), sulfur powder, and capping agents in water/tetrahydrofuran, micrometer bipyramidal sulfur particles enclosed with MWCNTs are synthesized. The MWCNTs spontaneously form a 3D conducting network inside and outside the sulfur particle. Along the edge of MWCNT framework, a sulfur particle‐free region is present, which comprises ≈35 vol% based on the total volume. These sulfur‐MWCNT bipyramidal particles are mixed with conductive carbon additive to prepare binder‐free cathode for Li–S cells. The Li–S cells deliver a specific discharge capacity of ≈1600 mAh g?1 at 0.05 C on the first cycle. In particular, these Li–S cells show high rate stability and Coulombic efficiency with deep discharge and charge (1.0–3.0 V vs Li/Li+). This resultant performance can arise from 1) homogeneous distribution of the conducting MWCNT framework and the carbon additive coating layer on the sulfur particle, which allow rapid Li+ ion/electrolyte diffusion and mitigation of polysulfide shuttle, respectively, and 2) the sulfur‐free buffer space accommodating volume expansion. It is expected that this new cathode design with the simple synthetic process can reduce the number of preparation steps, thus allowing the construction of a low‐cost Li–S battery.  相似文献   

13.
The main obstacles that hinder the development of efficient lithium sulfur (Li–S) batteries are the polysulfide shuttling effect in sulfur cathode and the uncontrollable growth of dendritic Li in the anode. An all‐purpose flexible electrode that can be used both in sulfur cathode and Li metal anode is reported, and its application in wearable and portable storage electronic devices is demonstrated. The flexible electrode consists of a bimetallic CoNi nanoparticle‐embedded porous conductive scaffold with multiple Co/Ni‐N active sites (CoNi@PNCFs). Both experimental and theoretical analysis show that, when used as the cathode, the CoNi and Co/Ni‐N active sites implanted on the porous CoNi@PNCFs significantly promote chemical immobilization toward soluble lithium polysulfides and their rapid conversion into insoluble Li2S, and therefore effectively mitigates the polysulfide shuttling effect. Additionally, a 3D matrix constructed with porous carbonous skeleton and multiple active centers successfully induces homogenous Li growth, realizing a dendrite‐free Li metal anode. A Li–S battery assembled with S/CoNi@PNCFs cathode and Li/CoNi@PNCFs anode exhibits a high reversible specific capacity of 785 mAh g?1 and long cycle performance at 5 C (capacity fading rate of 0.016% over 1500 cycles).  相似文献   

14.
Rechargeable lithium–sulfur batteries operate based on the interconversion between sulfur and Li2S. Due to its insoluble and insulated nature, Li2S deposition is kinetically sluggish, which has an important effect on performance of lithium–sulfur batteries. In this work, cobalt-edged nickel alloy is designed and used as host material of sulfur cathodes to manipulate the behavior and morphology of Li2S deposition. It is found that Co and Ni have different catalytic kinetic characteristics for Li2S deposition reactions, and the difference in nucleation and growth rates of Li2S and geometrical effect of Co-edged Ni alloy can cause a well-spaced morphology to prevent premature surface passivation, thereby improving sulfur utilization and rate capability of the cathodes. As a result, the thick sulfur cathode using cobalt-edged nickel as host material with a sulfur loading of 4.0 mg cm−2 shows an initial capacity of 1229.3 mA h g−1 at electrolyte/sulfur ratio of 8 µL mg−1, as well as high capacity retention of 92.2% at 0.2 C during 100 cycles. These results provide an alternative perspective not only for developing new mixed host materials for lithium–sulfur batteries, and also for further understanding the existing works using composite host materials.  相似文献   

15.
As one important component of sulfur cathodes, the carbon host plays a key role in the electrochemical performance of lithium‐sulfur (Li‐S) batteries. In this paper, a mesoporous nitrogen‐doped carbon (MPNC)‐sulfur nanocomposite is reported as a novel cathode for advanced Li‐S batteries. The nitrogen doping in the MPNC material can effectively promote chemical adsorption between sulfur atoms and oxygen functional groups on the carbon, as verified by X‐ray absorption near edge structure spectroscopy, and the mechanism by which nitrogen enables the behavior is further revealed by density functional theory calculations. Based on the advantages of the porous structure and nitrogen doping, the MPNC‐sulfur cathodes show excellent cycling stability (95% retention within 100 cycles) at a high current density of 0.7 mAh cm‐2 with a high sulfur loading (4.2 mg S cm‐2) and a sulfur content (70 wt%). A high areal capacity (≈3.3 mAh cm‐2) is demonstrated by using the novel cathode, which is crucial for the practical application of Li‐S batteries. It is believed that the important role of nitrogen doping promoted chemical adsorption can be extended for development of other high performance carbon‐sulfur composite cathodes for Li‐S batteries.  相似文献   

16.
The pursuit of rechargeable batteries with high energy density has triggered enormous efforts in developing cathode materials for lithium/sodium (Li/Na)-ion batteries considering their extremely high specific capacity. Many materials are being researched for battery applications, and transition metal oxide materials with remarkable electrochemical performance stand out among numerous cathode candidates for next-generation battery. Notwithstanding the merits, daunting challenges persist in the quest for further battery developments targeting lower cost, longer lifespan, improved energy density and enhanced safety. This is, in part, because the voltage hysteresis between the charge and discharge cycles, is historically avoided in intercalation electrodes because of its association with structural disorder and electrochemical irreversibility. Given the great potential of these materials for next-generation batteries, a review of the recent understanding of voltage hysteresis is timely. This review presents the origin of their undesirable behaviors and materials design criteria to mitigate them by integrating various schools of thought. A large amount of progressive characterization techniques related to voltage hysteresis are summarized from the literature, along with the corresponding measurable range used in their determination. Finally, promising design trends with eliminated voltage hysteresis are tentatively proposed to revive these important cathode materials toward practical applications.  相似文献   

17.
Lithium–sulfur (Li–S) batteries with a theoretical energy density of 2567 Wh kg−1 are very promising next-generation energy storage systems, but suffer from the insulativity of sulfur and Li2S, the shuttle effect due to the dissolution and migration of polysulfides, and the lithium dendrite issue. MXenes, a family of 2D transition metal carbides/nitrides, which have metallic conductivity, structural variety, strong chemical adsorption ability to polysulfides, effective catalytic effect for fast kinetics, and inducing effect for uniform growth of Li, exhibit promising potential for high-performance Li–S batteries. In this review, the recent progress and achievements of MXene-based Li–S batteries are summarized, including the use of MXenes in sulfur cathode, interlayer between cathode and separator, and Li anode. The architecture construction and chemical modification of MXenes, as well as hybridization with other materials are demonstrated. The enhancement on electrochemical performance and the related mechanisms of MXenes and MXene-based composites are discussed. Finally, challenges and perspectives of MXenes for Li–S battery application are also given.  相似文献   

18.
Li–S batteries are among the most promising energy storage technologies but their commercialization faces substantial challenges, largely due to difficulties in controlling their reaction pathways under practical conditions. Here, the synthesis of strongly coupled Fe3O4 and N‐doped carbon directly in flexible carbon cloth is demonstrated, as well as their novel use for hosting sulfur with outstanding performance for Li–S batteries. It is discovered that the synergistic effects of Fe3O4 and N‐carbon bring strong adsorption toward lithium polysulfide, and ensure nearly complete conversion of short‐chain polysulfide to Li2S during discharge. The Li2S solids generated on these novel hosts are extremely reactive and can be readily charged back to S without a noticeable overpotential. The critical roles of Fe3O4 and N‐doped carbon are studied and direct correlations are established between their surface concentration/crystallinity and the Li2S4 to Li2S conversion capacity. This novel manipulation of polysulfide conversion allows to fabricate freestanding and flexible sulfur cathodes that deliver a specific capacity of 1316 mAh g?1 at 0.1C and stable cycling for 1000 cycles at 0.2C under a high sulfur loading of ≈4.7 mg cm?2.  相似文献   

19.
Considering the ever‐growing climatic degeneration, sustainable and renewable energy sources are needed to be effectively integrated into the grid through large‐scale electrochemical energy storage and conversion (EESC) technologies. With regard to their competent benefit in cost and sustainable supply of resource, room‐temperature sodium‐ion batteries (SIBs) have shown great promise in EESC, triumphing over other battery systems on the market. As one of the most fascinating cathode materials due to the simple synthesis process, large specific capacity, and high ionic conductivity, Na‐based layered transition metal oxide cathodes commonly suffer from the sluggish kinetics, multiphase evolution, poor air stability, and insufficient comprehensive performance, restricting their commercialization application. Here, this review summarizes the recent advances in layered oxide cathode materials for SIBs through different optimal structure modulation technologies, with an emphasis placed on strategies to boost Na+ kinetics and reduce the irreversible phase transition as well as enhance the store stability. Meanwhile, a thorough and in‐depth systematical investigation of the structure–function–property relationship is also discussed, and the challenges as well as opportunities for practical application electrode materials are sketched. The insights brought forward in this review can be considered as a guide for SIBs in next‐generation EESC.  相似文献   

20.
The electrochemical performance of room-temperature sodium-sulfur batteries (SSBs) is limited by slow reaction kinetics and sulfur loss in the form of sodium polysulfides (SPSs). Here, it is demonstrated that through electron spin polarization, at no additional energy cost, an external magnetic field (M on) generated by a permanent magnet can significantly improve the SPSs adsorption capacity and reaction dynamics of a ferrimagnetic sulfur host. More specifically, the preparation of a carbon nanofiber/CoFe2O4/S (CNF/CoFe2O4/S) cathode with unprecedented performance and stability at ambient temperature is detailed when M on. It is experimentally and theoretically demonstrated that the magnetic field polarizes the electrons of Co ions, enhancing the adsorption of SPSs and their catalytic conversion. CNF/CoFe2O4/S cathodes with spin polarization provide unprecedented decay rates down to 0.0039% per cycle at 1.0 C for 2700 cycles. The performance of SSBs is further tested, which has 248 mAh g−1 under 1.0 C after 100 cycles when M on.  Furthermore, it is evidenced that even when removing the external magnetic field, the magnetic polarization effect persists, opening the door for practical applications. This study not only demonstrates an effective strategy to improve electrochemical performance in SSBs, but also contributes to the enrichments of spin effects in the fields of electrocatalysis.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号