The Fusion of Imidazolium‐Based Ionic Polymer and Carbon Nanotubes: One Type of New Heteroatom‐Doped Carbon Precursors for High‐Performance Lithium–Sulfur Batteries

Rational design of sulfur host materials with high electrical conductivity and strong polysulfides (PS) confinement is indispensable for high‐performance lithium–sulfur (Li–S) batteries. This study presents one type of new polymer material based on main‐chain imidazolium‐based ionic polymer (ImIP) and carbon nanotubes (CNTs); the polymer composites can serve as a precursor of CNT/NPC‐300, in which close coverage and seamless junction of CNTs by N‐doped porous carbon (NPC) form a 3D conductive network. CNT/NPC‐300 inherits and strengthens the advantages of both high electrical conductivity from CNTs and strong PS entrapping ability from NPC. Benefiting from the improved attributes, the CNT/NPC‐300‐57S electrode shows much higher reversible capacity, rate capability, and cycling stability than NPC‐57S and CNTs‐56S. The initial discharge capacity of 1065 mA h g^?1 is achieved at 0.5 C with the capacity retention of 817 mA h g^?1 over 300 cycles. Importantly, when counter bromide anion in the composite of CNTs and ImIP is metathesized to bis(trifluoromethane sulfonimide), heteroatom sulfur is cooperatively incorporated into the carbon hosts, and the surface area is increased with the promotion of micropore formation, thus further improving electrochemical performance. This provides a new method for optimizing porous properties and dopant components of the cathode materials in Li–S batteries.     

Facile Preparation of High‐Content N‐Doped CNT Microspheres for High‐Performance Lithium Storage

Herein, high‐content N‐doped carbon nanotube (CNT) microspheres (HNCMs) are successfully synthesized through simple spray drying and one‐step pyrolysis. HNCM possesses a hierarchically porous architecture and high‐content N‐doping. In particular, HNCM800 (HNCM pyrolyzed at 800 °C) shows high nitrogen content of 12.43 at%. The porous structure derived from well‐interconnected CNTs not only offers a highly conductive network and blocks diffusion of soluble lithium polysulfides (LiPSs) in physical adsorption, but also allows sufficient sulfur infiltration. The incorporation of N‐rich CNTs provides strong chemical immobilization for LiPSs. As a sulfur host for lithium–sulfur batteries, good rate capability and high cycling stability is achieved for HNCM/S cathodes. Particularly, the HNCM800/S cathode delivers a high capacity of 804 mA h g^?1 at 0.5 C after 1000 cycles corresponding to low fading rate (FR) of only 0.011% per cycle. Remarkably, the cathode with high sulfur loading of 6 mg cm^?2 still maintains high cyclic stability (capacity of 555 mA h g^?1 after 1000 cycles, FR 0.038%). Additionally, CNT/Co₃O₄ microspheres are obtained by the oxidation of CNTs/Co in the air. The as‐prepared CNT/Co₃O₄ microspheres are employed as an anode for lithium‐ion batteries and present excellent cycling performance.     

Functional Mesoporous Carbon‐Coated Separator for Long‐Life,High‐Energy Lithium–Sulfur Batteries

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.     

Designing a High‐Performance Lithium–Sulfur Batteries Based on Layered Double Hydroxides–Carbon Nanotubes Composite Cathode and a Dual‐Functional Graphene–Polypropylene–Al2O3 Separator

Designing an optimum cell configuration that can deliver high capacity, fast charge–discharge capability, and good cycle retention is imperative for developing a high‐performance lithium–sulfur battery. Herein, a novel lithium–sulfur cell design is proposed, which consists of sulfur and magnesium–aluminum‐layered double hydroxides (MgAl‐LDH)–carbon nanotubes (CNTs) composite cathode with a modified polymer separator produced by dual side coating approaches (one side: graphene and the other side: aluminum oxides). The composite cathode functions as a combined electrocatalyst and polysulfide scavenger, greatly improving the reaction kinetics and stabilizing the Coulombic efficiency upon cycling. The modified separator enhances further Li⁺‐ion or electron transport and prevents undesirable contact between the cathode and dendritic lithium on the anode. The proposed lithium–sulfur cell fabricated with the as‐prepared composite cathode and modified separator exhibits a high initial discharge capacity of 1375 mA h g^?1 at 0.1 C rate, excellent cycling stability during 200 cycles at 1 C rate, and superior rate capability up to 5 C rate, even with high sulfur loading of 4.0 mg cm^?2. In addition, the findings that found in postmortem chracterization of cathode, separator, and Li metal anode from cycled cell help in identifying the reason for its subsequent degradation upon cycling in Li–S cells.     

Bifunctional MOF‐Derived Carbon Photonic Crystal Architectures for Advanced Zn–Air and Li–S Batteries: Highly Exposed Graphitic Nitrogen Matters

Nitrogen‐rich porous carbons (NPCs) are the leading cathode materials for next‐generation Zn–air and Li–S batteries. However, most existing NPC suffers from insufficient exposure and harnessing of nitrogen‐dopants (NDs), constraining the electrochemical performance. Herein, by combining silica templating with in situ texturing of metal–organic frameworks, a new bifunctional 3D nitrogen‐rich carbon photonic crystal architecture of simultaneously record‐high total pore volume (13.42 cm³ g^?1), ultralarge surface area (2546 m² g^?1), and permeable hierarchical macro‐meso‐microporosity is designed, enabling sufficient exposure and accessibility of NDs. Thus, when used as cathode catalysts, the Zn–air battery delivers a fantastic capacity of 770 mAh g_Zn^?1 at an unprecedentedly high rate of 120 mA cm^?2, with an ultrahigh power density of 197 mW cm^?2. When hosting 78 wt% sulfur, the Li–S battery affords a high‐rate capacity of 967 mAh g^?1 at 2 C, with superb stability over 1000 cycles at 0.5 C (0.054% decay rate per cycle), comparable to the best literature value. The results prove the dominant role of highly exposed graphitic‐N in boosting both cathode performances.     

Freestanding Bilayer Carbon–Sulfur Cathode with Function of Entrapping Polysulfide for High Performance Li–S Batteries

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.     

Mesoporous Carbon Nanocube Architecture for High‐Performance Lithium–Oxygen Batteries

One of the major challenges to develop high‐performance lithium–oxygen (Li–O₂) battery is to find effective cathode catalysts and design porous architecture for the promotion of both oxygen reduction reactions and oxygen evolution reactions. Herein, the synthesis of mesoporous carbon nanocubes as a new cathode nanoarchitecture for Li–O₂ batteries is reported. The oxygen electrodes made of mesoporous carbon nanocubes contain numerously hierarchical mesopores and macropores, which can facilitate oxygen diffusion and electrolyte impregnation throughout the electrode, and provide sufficient spaces to accommodate insoluble discharge products. When they are applied as cathode catalysts, the Li–O₂ cells deliver discharge capacities of 26 100 mA h g^?1 at 200 mA g^?1, which is much higher than that of commercial carbon black catalysts. Furthermore, the mesoporous nanocube architecture can also serve as a conductive host structure for other highly efficient catalysts. For instance, the Ru functionalized mesoporous carbon nanocubes show excellent catalytic activities toward oxygen evolution reactions. Li–O₂ batteries with Ru functionalized mesoporous carbon nanocube catalysts demonstrate a high charge/discharge electrical energy efficiency of 86.2% at 200 mA g^?1 under voltage limitation and a good cycling performance up to 120 cycles at 400 mA g^?1 with the curtaining capacity of 1000 mA h g^?1.     

Hierarchical Free‐Standing Carbon‐Nanotube Paper Electrodes with Ultrahigh Sulfur‐Loading for Lithium–Sulfur Batteries

The rational combination of conductive nanocarbon with sulfur leads to the formation of composite cathodes that can take full advantage of each building block; this is an effective way to construct cathode materials for lithium–sulfur (Li–S) batteries with high energy density. Generally, the areal sulfur‐loading amount is less than 2.0 mg cm^?2, resulting in a low areal capacity far below the acceptable value for practical applications. In this contribution, a hierarchical free‐standing carbon nanotube (CNT)‐S paper electrode with an ultrahigh sulfur‐loading of 6.3 mg cm^?2 is fabricated using a facile bottom–up strategy. In the CNT–S paper electrode, short multi‐walled CNTs are employed as the short‐range electrical conductive framework for sulfur accommodation, while the super‐long CNTs serve as both the long‐range conductive network and the intercrossed mechanical scaffold. An initial discharge capacity of 6.2 mA·h cm^?2 (995 mA·h g^?1), a 60% utilization of sulfur, and a slow cyclic fading rate of 0.20%/cycle within the initial 150 cycles at a low current density of 0.05 C are achieved. The areal capacity can be further increased to 15.1 mA·h cm^?2 by stacking three CNT–S paper electrodes—resulting in an areal sulfur‐loading of 17.3 mg cm^?2—for the cathode of a Li–S cell. The as‐obtained free‐standing paper electrode are of low cost and provide high energy density, making them promising for flexible electronic devices based on Li–S batteries.     

Engineered Interfusion of Hollow Nitrogen‐Doped Carbon Nanospheres for Improving Electrochemical Behavior and Energy Density of Lithium–Sulfur Batteries

Hollow nanostructures are one of promising sulfur host materials for lithium–sulfur (Li–S) batteries, but the ineffective contact among discrete particles usually generates overall poor electrical conductivity and low volumetric energy density. A new interfused hollow nitrogen‐doped carbon (HNPC) material, derived from imidazolium‐based ionic polymer (ImIP)‐encapsulated zeolitic imidazolate framework‐8 (ZIF‐8), is reported. A novel method for ZIF‐8 disassembly induced by the decomposition of the ImIP shell is proposed. The unique structural superiority gives the resultant electrodes remarkable cycling stability, high rate capability, and large volumetric energy density. A stable reversible discharge capacity over 562 mA h g^?1 at 2 C is achieved after prolonged cycling for 800 cycles and the average capacity decay per cycle is as low as 0.035%. The electrochemical performance achieved greatly surpasses that of ZIF‐8‐derived carbon matrices and conventional nitrogen‐doped carbon materials. This proposed methodology opens a new avenue for the design of hollow‐structured carbon nanoarchitectures with target functionalities.     

Facile Solid‐State Growth of 3D Well‐Interconnected Nitrogen‐Rich Carbon Nanotube–Graphene Hybrid Architectures for Lithium–Sulfur Batteries

Constructing 3D carbon structures built from carbon nanotubes (CNTs) and graphene has been considered as an effective approach to achieve superior properties in energy conversion and storage because of the synergistic combination of the advantages of each building block. Herein, a facile solid‐state growth strategy is reported for the first time to fabricate highly nitrogen doped CNT–graphene 3D nanostructures without the necessity to use chemical vapor deposition. As cathode hosts for lithium–sulfur batteries, the hybrid architectures exhibit reversible capacities of 1314 and 922 mAh g^?1 at 0.2 and 1 C, respectively, and a capacity retention of 97% after 200 cycles at a high rate of 2 C, revealing their great potential for energy storage application.     

All‐Purpose Electrode Design of Flexible Conductive Scaffold toward High‐Performance Li–S Batteries

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).     

Sulfurized Polyacrylonitrile Cathodes with High Compatibility in Both Ether and Carbonate Electrolytes for Ultrastable Lithium–Sulfur Batteries

Sulfurized polyacrylonitrile (SPAN) is a promising material capable of suppressing polysulfide dissolution in lithium–sulfur (Li–S) batteries with carbonate electrolyte. However, undesirable spontaneous formation of soluble polysulfides may arise in the ether electrolyte, and the conversion of sulfur in SPAN during the lithiation/delithiation processes is yet to be understood. Here, a highly reliable Li–S system using a freestanding fibrous SPAN cathode, as well as the sulfur conversion mechanism involved, is demonstrated. The SPAN shows high compatibility in both ether and carbonate electrolytes. The sulfur atoms existing in the form of short ? S₂? and ? S₃? chains are covalently bonded to the pyrolyzed PAN backbone. The electrochemical reduction of the SPAN by Li⁺ is a single‐phase solid–solid reaction with Li₂S as the sole discharge product. Meanwhile, the parasitic reaction between Li⁺ and C?N bonds exists upon the first discharge, and the residual Li⁺ enhances the conductivity of the backbone. The recharge ability and rate capability are kinetically dominated by the activation of Li₂S nanoflakes generated during discharge. At 800 mA g^?1, a specific capacity of 1180 mAh g^?1 is realized without capacity fading in the measured 1000 cycles, which makes SPAN promising for practical application.     

A Flexible 3D Multifunctional MgO‐Decorated Carbon Foam@CNTs Hybrid as Self‐Supported Cathode for High‐Performance Lithium‐Sulfur Batteries

One of the critical challenges to develop advanced lithium‐sulfur (Li‐S) batteries lies in exploring a high efficient stable sulfur cathode with robust conductive framework and high sulfur loading. Herein, a 3D flexible multifunctional hybrid is rationally constructed consisting of nitrogen‐doped carbon foam@CNTs decorated with ultrafine MgO nanoparticles for the use as advanced current collector. The dense carbon nanotubes uniformly wrapped on the carbon foam skeletons enhance the flexibility and build an interconnected conductive network for rapid ionic/electronic transport. In particular, a synergistic action of MgO nanoparticles and in situ N‐doping significantly suppresses the shuttling effect via enhanced chemisorption of lithium polysulfides. Owing to these merits, the as‐built electrode with an ultrahigh sulfur loading of 14.4 mg cm^?2 manifests a high initial areal capacity of 10.4 mAh cm^?2, still retains 8.8 mAh cm^?2 (612 mAh g^?1 in gravimetric capacity) over 50 cycles. The best cycling performance is achieved upon 800 cycles with an extremely low decay rate of 0.06% at 2 C. Furthermore, a flexible soft‐packaged Li‐S battery is readily assembled, which highlights stable electrochemical characteristics under bending and even folding. This cathode structural design may open up a potential avenue for practical application of high‐sulfur‐loading Li‐S batteries toward flexible energy‐storage devices.     

Walnut‐Like Multicore–Shell MnO Encapsulated Nitrogen‐Rich Carbon Nanocapsules as Anode Material for Long‐Cycling and Soft‐Packed Lithium‐Ion Batteries

Metal oxide‐based nanomaterials are widely studied because of their high‐energy densities as anode materials in lithium‐ion batteries. However, the fast capacity degradation resulting from the large volume expansion upon lithiation hinders their practical application. In this work, the preparation of walnut‐like multicore–shell MnO encapsulated nitrogen‐rich carbon nanocapsules (MnO@NC) is reported via a facile and eco‐friendly process for long‐cycling Li‐ion batteries. In this hybrid structure, MnO nanoparticles are uniformly dispersed inside carbon nanoshells, which can simultaneously act as a conductive framework and also a protective buffer layer to restrain the volume variation. The MnO@NC nanocapsules show remarkable electrochemical performances for lithium‐ion batteries, exhibiting high reversible capability (762 mAh g^?1 at 100 mA g^?1) and stable cycling life (624 mAh g^?1 after 1000 cycles at 1000 mA g^?1). In addition, the soft‐packed full batteries based on MnO@NC nanocapsules anodes and commercial LiFePO₄ cathodes present good flexibility and cycling stability.     

In Situ Formation of Copper‐Based Hosts Embedded within 3D N‐Doped Hierarchically Porous Carbon Networks for Ultralong Cycle Lithium–Sulfur Batteries

Lithium–sulfur (Li–S) batteries are promising energy storage systems due to their large theoretical energy density of 2600 Wh kg^?1 and cost effectiveness. However, the severe shuttle effect of soluble lithium polysulfide intermediates (LiPSs) and sluggish redox kinetics during the cycling process cause low sulfur utilization, rapid capacity fading, and a low coulombic efficiency. Here, a 3D copper, nitrogen co‐doped hierarchically porous graphitic carbon network developed through a freeze‐drying method (denoted as 3D Cu@NC‐F) is prepared, and it possesses strong chemical absorption and electrocatalytic conversion activity for LiPSs as highly efficient sulfur host materials in Li–S batteries. The porous carbon network consisting of 2D cross‐linked ultrathin carbon nanosheets provides void space to accommodate volumetric expansion upon lithiation, while the Cu, N‐doping effect plays a critical role for the confinement of polysulfides through chemical bonding. In addition, after sulfuration of Cu@NC‐F network, the in situ grown copper sulfide (Cu_xS) embedded within Cu_xS@NC/S‐F composite catalyzes LiPSs conversion during reversible cycling, resulting in low polarization and fast redox reaction kinetics. At a current density of 0.1 C, the Cu_xS@NC/S‐F composites' electrode exhibits an initial capacity of 1432 mAh g^?1 and maintains 1169 mAh g^?1 after 120 cycles, with a coulombic efficiency of nearly 100%.     

A Free‐Standing and Ultralong‐Life Lithium‐Selenium Battery Cathode Enabled by 3D Mesoporous Carbon/Graphene Hierarchical Architecture

High capacity cathode materials for long‐life rechargeable lithium batteries are urgently needed. Selenium cathode has recently attracted great research attention due to its comparable volumetric capacity to but much better electrical conductivity than widely studied sulfur cathode. However, selenium cathode faces similar issues as sulfur (i.e., shuttling of polyselenides, volumetric expansion) and high performance lithium‐selenium batteries (Li–Se) have not yet been demonstrated at selenium loading >60% in the electrode. In this work, a 3D mesoporous carbon nanoparticles and graphene hierarchical architecture to storage selenium as binder‐free cathode material (Se/MCN‐RGO) for high energy and long life Li–Se batteries is presented. Such architecture not only provides the electrode with excellent electrical and ionic conductivity, but also efficiently suppresses polyselenides shuttling and accommodates volume change during charge/discharge. At selenium content of 62% in the entire cathode, the free‐standing Se/MCN‐RGO exhibits high discharge capacity of 655 mAh g^?1 at 0.1 C (97% of theoretical capacity) and long cycling stability with a very small capacity decay of 0.008% per cycle over 1300 cycles at 1 C. The present report demonstrates significant progress in the development of high capacity cathode materials for long‐life Li batteries and flexible energy storage device.     

Flexible Electrocatalytic Nanofiber Membrane Reactor for Lithium/Sulfur Conversion Chemistry

Severe lithium polysulfide (LiPS) shuttle effects and sluggish electrochemical conversion kinetics constitute bottlenecks in developing fast‐rechargeable, high‐energy, and high‐power Li/S batteries. Here, a flexible and conductive TiN–Ti₄O₇ core‐shell nanofiber (TiNOC) membrane reactor is designed to electrocatalytically mediate Li/S conversion chemistry. The Ti, N, and O atoms in the nanofiber function as electrocatalysts and chemical confinement active sites to initiate long‐chain LiPS conversion and phase change, as well as to suppress soluble LiPS shuttling. With a sulfur cathode‐membrane reactor module configuration, Li/S cells possess a high sulfur utilization of 91.20%, good rate capability of 869.10 mA h g^?1, and high capacity retention of 92.49%, with a coulomb efficiency of 99.57% after 200 cycles at 5 C. Density functional theory (DFT) calculations revealed that the optimized chemisorption configurations facilitate the elongation of Li? S and S? S bonds, as well as charge transfer along Ti? S and Li? N bonds, which favors bond breakage, bond formation, and the activation of solid‐state S₈, Li₂S₂, and Li₂S. Layer‐by‐layer module stacking provides Li/S batteries with a high areal sulfur loading of 12.00 mg cm^?2 to deliver a high areal capacity of 14.40 mA h cm^?2 at 2.26 mA. Two batteries in series can power real‐world applications such as light emitting diode (LED) bulbs with a high energy output of 69.00 mW h.     

Manipulating Polysulfide Conversion with Strongly Coupled Fe3O4 and Nitrogen Doped Carbon for Stable and High Capacity Lithium–Sulfur Batteries

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.     

Combined High Catalytic Activity and Efficient Polar Tubular Nanostructure in Urchin‐Like Metallic NiCo2Se4 for High‐Performance Lithium–Sulfur Batteries

Urchin‐shaped NiCo₂Se₄ (u‐NCSe) nanostructures as efficient sulfur hosts are synthesized to overcome the limitations of lithium–sulfur batteries (LSBs). u‐NCSe provides a beneficial hollow structure to relieve volumetric expansion, a superior electrical conductivity to improve electron transfer, a high polarity to promote absorption of lithium polysulfides (LiPS), and outstanding electrocatalytic activity to accelerate LiPS conversion kinetics. Owing to these excellent qualities as cathode for LSBs, S@u‐NCSe delivers outstanding initial capacities up to 1403 mAh g^?1 at 0.1 C and retains 626 mAh g^?1 at 5 C with exceptional rate performance. More significantly, a very low capacity decay rate of only 0.016% per cycle is obtained after 2000 cycles at 3 C. Even at high sulfur loading (3.2 mg cm^?2), a reversible capacity of 557 mAh g^?1 is delivered after 600 cycles at 1 C. Density functional theory calculations further confirm the strong interaction between NCSe and LiPS, and cytotoxicity measurements prove the biocompatibility of NCSe. This work not only demonstrates that transition metal selenides can be promising candidates as sulfur host materials, but also provides a strategy for the rational design and the development of LSBs with long‐life and high‐rate electrochemical performance.     

Advanced Lithium–Sulfur Batteries Enabled by a Bio‐Inspired Polysulfide Adsorptive Brush

Issues with the dissolution and diffusion of polysulfides in liquid organic electrolytes hinder the advance of lithium–sulfur batteries for next‐generation energy storage. To trap and re‐utilize the polysulfides without hampering lithium ion conductivity, a bio‐inspired, brush‐like interlayer consisting of zinc oxide (ZnO) nanowires and interconnected conductive frameworks is proposed. The chemical effect of ZnO on capturing polysulfides has been conceptually confirmed, initially by using a commercially available macroporous nickel foam as a conductive backbone, which is then replaced by a free‐standing, ultra‐light micro/mesoporous carbon (C) nanofiber mat for practical application. Having a high sulfur loading of 3 mg cm^?2, the sulfur/multi‐walled carbon nanotube composite cathode with a ZnO/C interlayer exhibits a reversible capacity of 776 mA h g^?1 after 200 cycles at 1C with only 0.05% average capacity loss per cycle. A good cycle performance at a high rate can be mainly attributed to the strong chemical bonding between ZnO and polysulfides, fast electron transfer, and an optimized ion diffusion path arising from a well‐organized nanoarchitecture. These results herald a new approach to advanced lithium–sulfur batteries using brush‐like chemi‐functional interlayers.