Multifunctional Interlayer Research Articles

Boosting the polysulfides adsorption-catalysis process on carbon nanotube interlayer via a simple polyelectrolyte-assisted strategy for high-performance lithium sulfur batteries

The introduction of conductive interlayer is an effective strategy to improve the sulfur utilization and restrict the migration of polysulfides for high-performance Li-S battery. Herein, a multifunctional CNT based interlayer was obtained by a simple polyelectrolyte (PDDA-TFSI) modified method. Due to the electro-positivity of PDDA-TFSI and the electronic coupling between CNT and PDDA-TFSI, the CNT/PDDA-TFSI interlayer exhibits a strong adsorption and effective catalysis towards polysulfides. Furthermore, the continuous CNT network ensures the successful electron transport during the charge-discharge process. As expected, the electrochemical properties of Li-S battery can be promoted significantly with the assistance of CNT/PDDA-TFSI interlayer. Even after 300 cycles, the CNT/PDDA-TFSI interlayer-based Li-S battery also delivers a higher capacity retention of 79.2%, proceeding Li-S batteries with and without CNT interlayer. This work proves that CNT/PDDA-TFSI film as a multifunctional interlayer has a promising application in advanced Li-S battery.

Hydrophobic Fluorinated Conjugated Polymer as a Multifunctional Interlayer for High-Performance Perovskite Solar Cells

It is known that the perovskite/hole transport layer (HTL) interface is a great limit to achieving high-performance perovskite solar cells (PSCs). Aiming to solve this problem, we introduce a napht...

SiO2 hollow nanotubes composite aramid fiber interlayer for absorbtion of polysulfides in highly stable lithium-sulfur batteries

The shuttle effect and poor conductivity of the sulfur are the major obstacles to the commercialization of lithium-sulfur batteries. In this paper, hollow SiO2 nanotubes (SNTs) were prepared to combine with the aramid fiber paper (AP) as a multifunctional interlayer (SNTs-AP) in the Lithium-sulfur battery. SNTs-AP interlayer could efficiently suppress the polysulfide shuttle effect through polarization sites of SiO2 and enhance the electrical conductivity of lithium-sulfur batteries by forming conductive network. Moreover, the SNTs could accelerate the conversion process of long-chain polysulfides to short-chain polysulfides. The lithium-sulfur batteries with SNTs-AP interlayer exhibits a stable cycling performance with initial specific capacity of 1018mAh/g and average coulombic efficiency of 97.5% at 0.2C. Furthermore, the battery with the SNTs-AP interlayer exhibits a low cyclic decay rate of 0.073% after 350 cycles at 1 C. The above results proves that the SNTs-AP interlayer could provide a strategy for preparing high-stability lithium-sulfur batteries.

Enhanced interfacial characteristics of perovskite solar cell with multi-functional organic hole-selective interlayer

In solution-processed organic and inorganic halide perovskite solar cells (PSCs), managing the interfacial characteristics between multi-layers has been a crucial factor in determining their performance and stability. Here, we newly design an indolocarbazole-based organic molecule that can enhance the interfacial properties between a solution-processed NiOx hole transport layer and perovskite in p-i-n planar PSC. Especially, to be beneficial to this architecture, its visible transparency and energy level are optimized, and its chemical structure is crosslinked for better solution processability as a hole-selective interlayer. More importantly, it can passivate the defects in the perovskite film, consequently enhancing the quality of the film and suppressing non-radiative recombination in the devices. With this interface modification, we confirm that the performance and stability of PSC devices are largely enhanced.

Attapulgite and multiwalled carbon nanotubes co-integrated hierarchical porous polyacrylonitrile membrane as a multifunctional interlayer for lithium-sulfur batteries with enhanced performance

• ATTP and MWCNTs co-integrated porous PAN membrane was first fabricated. • The membrane was investigated as a multifunctional interlayer for Li-S batteries. • A synergistic effect of ATTP and MWCNTs effectively suppress the shuttle effect. • The cell with such interlayer demonstrates superior cycling stability . As a kind of natural porous nanorods, attapulgites (ATTP) are widely used in many fields because of their high specific surface area, high porosity and strong adsorption ability. In this work, ATTP and multiwalled carbon nanotubes (MWCNTs) co-integrated polyacrylonitrile (PAN) hierarchical porous membrane (ATTP/CNTs@PAN) has been fabricated and investigated as a multifunctional interlayer for lithium-sulfur batteries. Due to a synergistic effect of ATTP and the carboxylated MWCNTs, the porous interlayer is able to effectively suppress the shuttle effect by trapping and confining the dissolved polysulfides. Meanwhile, the addition of MWCNTs improves the conductivity of the composite membrane, which is beneficial for the reutilization of the active species. Therefore, the cells with the interlayer demonstrates superior electrochemical performance, delivering a high initial discharge capacity of 1283 mAh g −1 at 0.2 C, and retaining 785 mAh g −1 after 300 cycles with a Coulombic efficiency exceeding 99%. Meaningfully, this porous composite membrane is low-cost and very effective for high performance Li-S batteries.

Towards high-performance lithium-sulfur battery: Investigation on the capability of metalloid to regulate polysulfides

Lithium sulfur batteries (LSBs) have been a promising rechargeable energy-storage system depending on non-toxicity, low-cost and high theoretical specific capacity. However, the inevitably shuttling of dissolved polysulfides in ether electrolyte and the sluggish redox kinetics still become the obstacles on the way of the commercialization of LSBs. Placing a multifunctional interlayer has been proven a valid method to alleviate the shuttling and boost the conversion of polysulfides. Herein, a germanium (Ge)-doped nitrogen (N)-rich carbon skeleton (GNCS) independent interlayer was proposed through a facile electrospinning technique for LSBs. In this work, Ge nanoparticles, which are embedded in carbon skeleton homogeneously and massively, simultaneously act as catalysts and absorbents for their inherent electronic conductivity and reliable affinity to polysulfides. Meanwhile, the polyacrylonitrile (PAN)-derived nitrogen-rich carbon nanofibers build a three-dimensional conductive network for expediting electron transportation of the entire system. The experimental results demonstrate that the LSBs using GNCS interlayers exhibit superior rate performance with the ultrahigh initial capacity of 1680.5 mAh g−1 at 0.1C, as well as a decent long-cycling performance with high capacity of 755.6 mAh g−1 after 300 cycling at 1C. This design could not only widen horizons on the usage of metalloids nanoparticles to mediate the activity of polysulfides, but also introduce a facile and practical electrospinning strategy to produce the novel interlayers for realizing the industrialization of LSBs.

Multifunctional B/N Co‐Doped Graphene Interlayer for Fast and Stable Lithium‐Sulfur Batteries

AbstractA boron (B)/nitrogen (N) co‐doped graphene is synthesized via an two‐steps method and used as an interlayer for lithium‐sulfur (Li−S) batteries. Due to the excellent electronic conductivity and dense sheet constructure of graphene, it can improve the conductive network, reduce the pores of polypropylene (PP) membrane, and consequently inhibit the penetration of polysulfide in Li−S batteries. More importantly, the co‐doped B and N atoms play the role of Lewis acid‐base, which have a strong adsorption capacity to lithium ions and as well as sulfur ions during reactions, and thus inhibit the “shuttle effect” and accelerate the conversion reactions of polysulfides. Based on this multifunctional interlayer, the cells exhibit a high initial capacity of 1448 mAh g−1, and achieve a reversible capacity of 578 mAh g−1 under a large rate of 2 C after 350 cycles with a capacity decay of 0.015 % per cycle. These results demonstrate the enormous potential of the B/N co‐doped graphene as the interlayer for high‐performance Li−S batteries.

Rational design of a cobalt sulfide nanoparticle-embedded flexible carbon nanofiber membrane electrocatalyst for advanced lithium–sulfur batteries

Both the sluggish redox kinetics and severe polysulfide shuttling behavior hinders the commercialization of lithium–sulfur (Li–S) battery. To solve these obstacles, we design a cobalt sulfide nanoparticle-embedded flexible carbon nanofiber membrane (denoted as CoS2@NCF) as sulfiphilic functional interlayer materials. The hierarchically porous structure of carbon nanofiber is conducive to immobilizing sulfur species and facilitating lithium-ion penetration. Moreover, electrocatalytic CoS2 nanoparticles can significantly enhance the catalytic effect, achieving favorable adsorption-diffusion-conversion interface of polysulfide. Combined with these synergistic features, the assembled Li–S cell with CoS2@NCF interlayer exhibited a great discharge capacity of 950.9 mAh g−1 with prolonged cycle lifespan at 1 C (maintained 648.1 mAh g−1 over 500 cycles). This multifunctional interlayer material used in this contribution provides an advanced route for developing high-energy-density Li–S battery.

Anti‐Corrosive and Zn‐Ion‐Regulating Composite Interlayer Enabling Long‐Life Zn Metal Anodes

AbstractThe Zn metal anode is considered one of the most promising anode choices for aqueous Zn‐based batteries. Nevertheless, dendrites and intricate side reactions have hindered its usage. Herein, an elastic and anti‐corrosive interlayer is introduced to address the problem. The idiosyncratic dielectric behavior of amorphous and nanostructured silicon nitride (Si3N4) is utilized to manipulate the ion kinetics, by uniformly dispersing its particles in polyacrylonitrile (PAN) to fabricate an interlayer attached to Zn metal (PSN‐Zn). PAN serves as an elastic constraint to inhibit drastic dendrite evolution and blocks H2O/O2 corrosion, and Si3N4 with a high dielectric constant can facilitate the ion kinetics and endow uniform Zn deposition. The electrochemical stability and deposition consistency of the Zn anodes are greatly improved, with an extended lifespan of over 800 h at 1 mA cm−2. Even under draconian deep‐discharging (DODZn = 60%) and high current density (10 mA cm−2), the PSN‐Zn anode can still operate stably for over 250 h. The effect of the dielectric property is systematically discussed and verified by experiments and theoretical simulations. Moreover, full cells with vanadium‐ and manganese‐based cathodes also deliver excellent performance, indicating the use of the multifunctional interlayer as an appealing approach for rechargeable aqueous zinc batteries.

Highly oriented MIL-101(Cr) continuous films grown on carbon cloth as efficient polysulfide barrier for lithium-sulfur batteries

The development of lithium-sulfur (Li-S) batteries is obstructed by polysulfide-shuttling and sluggish conversion kinetics during the process of charge and discharge. Herein, a highly oriented MIL-101(Cr) continuous film is developed on carbon cloth and utilized as trustworthy interlayer for lithium-sulfur batteries. This interlayer possesses a unique hierarchical porous structure and abundant active sites, providing efficient confinement of polysulfides through strong physical/chemical adsorption. Specially, the Lewis acidic Cr(III) centers of MIL-101(Cr) films are able to coordinate with polysulfides through Lewis acid-base interactions. Moreover, MIL-101(Cr) films also have the electrocatalytic effect of promoting the conversion of polysulfides. Benefiting from these features, this composite interlayer establishes an efficient barrier to inhibit the shuttling of polysulfides. Consequently, the as-prepared multifunctional interlayer exhibits a remarkable rate performance of 635 mAh g−1 at 3 C, a superior cycle stability with a low-capacity decay of 0.039% per cycle over 500 cycles at 1 C and high areal specific capacity of 4.3 mAh cm−2 under raised sulfur loading (5.1 mg cm−2).

Hierarchical Porous Carbon Membrane Embedded with Pyrolyzed Co‐Based Metal−Organic Frameworks as Multifunctional Interlayers for Advanced Li−SeS2 Batteries

Selenium disulfide (SeS2) possesses competitive advantages over pure sulfur or selenium as an electrode material for lithium storage. However, the shutting effect and slow conversion rate of soluble lithium polysulfides/polyselenides (LiPSs/LiPSes) compromise the practical application of Li−SeS2 batteries. Herein, a ZIF‐67@PAN‐derived Co−N−C@C multifunctional porous membrane as the LiPSs/LiPSes trapping barrier for Li−SeS2 batteries is proposed. The hierarchical porous conductive network facilitates the transport of electrons/lithium ions. Meanwhile, the Co−N−C architecture not only has chemical interaction for trapping the mobile LiPSs/LiPSes, but also catalyzes the LiPSs/LiPSes conversion reaction during the cycling process. Benefiting from the multifunctional capabilities, the constructed Li−SeS2 cells with the aforementioned interlayer exhibit a high capacity utilization of 978 mAh g−1 at 0.2 A g−1, together with an excellent rate capacity of 532 mAh g−1 at 3 A g−1 and also superior cycle life with a capacity of 557 mAh g−1 after 300 cycles at 1 A g−1. More strikingly, they show promising capacity with stable cell performance with a mass loading of 4 mg cm−2.

Fe-doped Ni(OH)2 nanosheets grown on carbon fiber cloths as cathode interlayers for high-performance lithium-sulfur batteries

Lithium-sulfur batteries have attracted extensive attentions due to their high energy densities and low cost. However, the low surfur utilization and shuttling of lithium polysulfides hinder their practical applications. Herein, a multifunctional interlayer composed of Fe-doped Ni(OH)2 nanosheets grown on carbon fiber cloth is reported. Fe-doping in the Ni(OH)2 nanosheets improves the interactions and adsorption of polysulfides. Promoted reaction kinetics, higher rating performance and more stable long-term cycling are achieved. As a result, the Fe-Ni(OH)2/CFC interlayer enables an initial capacity of 1318 mAh g−1 at 0.5C, and a capacity retention of 923 mAh g−1 after 500 cycles with a low capacity fading rate.

Sandwiched Cathodes Assembled from CoS2 -Modified Carbon Clothes for High-Performance Lithium-Sulfur Batteries.

Structural design of advanced cathodes is a promising strategy to suppress the shuttle effect for lithium‐sulfur batteries (LSBs). In this work, the carbon cloth covered with CoS2 nanoparticles (CC‐CoS2) is prepared to function as both three‐dimensional (3D) current collector and physicochemical barrier to retard migration of soluble lithium polysulfides. On the one hand, the CC‐CoS2 film works as a robust 3D current collector and host with high conductivity, high sulfur loading, and high capability of capturing polysulfides. On the other hand, the 3D porous CC‐CoS2 film serves as a multifunctional interlayer that exhibits efficient physical blocking, strong chemisorption, and fast catalytic redox reaction kinetics toward soluble polysulfides. Consequently, the Al@S/AB@CC‐CoS2 cell with a sulfur loading of 1.2 mg cm−2 exhibits a high rate capability (≈823 mAh g−1 at 4 C) and delivers excellent capacity retention (a decay of ≈0.021% per cycle for 1000 cycles at 4 C). Moreover, the sandwiched cathode of CC‐CoS2@S/AB@CC‐CoS2 is designed for high sulfur loading LSBs. The CC‐CoS2@S/AB@CC‐CoS2 cells with sulfur loadings of 4.2 and 6.1 mg cm−2 deliver high reversible capacities of 1106 and 885 mAh g−1, respectively, after 100 cycles at 0.2 C. The outstanding electrochemical performance is attributed to the sandwiched structure with active catalytic component.

Polysulfide Filter and Dendrite Inhibitor: Highly Graphitized Wood Framework Inhibits Polysulfide Shuttle and Lithium Dendrites in Li–S Batteries

AbstractThe design and manufacture of advanced materials based on biomaterials provide new opportunities to solve many technological challenges. In this work, a highly graphitized wood framework (GWF) with a porous tunnel structure and microvilli is constructed as a multifunctional interlayer to improve the electrochemical performance of lithium–sulfur (Li–S) batteries. The GWF not only retains the 3D transport network of wood, but also offers increased deposition sites for polysulfides through the microvilli which grow on the inner surfaces of the carbon tunnels. Electrochemical tests show that GWF effectively enhances the initial discharge capacity of the Li–S battery to 1593 mAh g−1at 0.05 C, with a low capacity decline of 0.06% per cycle at 1 C. Besides, the GWF interlayer also effectively protects lithium anodes from corrosion by Sx2−, thus they still keep their metallic luster and clean surface even after long charge‐discharge cycles. These enhancements are attributed to the high conductivity, abundant microvilli, and tunnel confinement effects of GWF, which effectively inhibit the shuttle effect of polysulfides by the same principle as nose hairs filtering the air. This work presents a new understanding of bionic/biomaterials and a new strategy to improve the performance of Li–S batteries.

Guiding Uniformly Distributed Li-Ion Flux by Lithiophilic Covalent Organic Framework Interlayers for High-Performance Lithium Metal Anodes.

Lithium (Li) metal anodes are regarded as prospective anode materials in next-generation secondary lithium batteries due to their ultrahigh theoretical capacities and ultralow potentials. However, inhomogeneous lithium deposition and uncontrollable growth of lithium dendrites always give rise to the low lithium utilization, rapid capacity fading, and poor cycling performance. Herein, we design the lithiophilic covalent organic frameworks (COFs) containing preorganized triazine rings and carbonyl groups as the multifunctional interlayer in lithium metal batteries (LMBs). Triazine rings rich in lone pair electrons can act as the donor attracting Li ions, and carbonyl groups serve as Li-anchoring sites effectively coordinating Li ions. These periodic arranged subunits significantly guide uniform Li ion flux distribution, guarantee smooth Li deposition and less lithium dendrite formation. Consequently, the symmetric batteries with COF interlayers exhibit an extraordinary cycling stability for more than 2450 and 1000 h with ultralow polarization voltage of about 12 and 14 mV at 0.5 and 1.0 mA cm-1. Coupling with sulfur (S) cathodes and LiFePO4 (LFP) cathodes, the full cells also demonstrate superb energy density achievement and rate performance. With introducing lithiophilic COFs interlayers, the Li-LFP batteries exhibit high capacity of 150 mAh g-1 and 86% capacity retention after 450 cycles at 0.5 C.

Mg-Al layered double hydroxides modified N-doped porous carbon nanofibers film as cathodic interlayer for high performance Li-S batteries

Lithium-sulfur (Li-S) battery as a promising energy storage technology has attracted extensive concern. However, their practical performance is seriously limited by the dissolution and diffusion of long-chain polysulfides. In this study, a multifunctional cathodic interlayer was constructed, which composed by Mg-Al layered double hydroxides (MALDHs) modified N-doped honeycomb-like porous carbon nanofibers (NPCNFs). The NPCNFs in the prepared interlayer can combine the physical confinement of the porous structure and the chemical role of the nitrogen atoms to suppress the dissolved lithium polysulfide (LiPS). Furthermore, highly conductive interlayer contains NPCNFs can be regarded as a second current collector, and the hierarchical pores is beneficial to adapt the volume change during the redox process. More importantly, the obtained polar MALDHs not only can strongly interact with LiPS by chemical combination, but also enhance the redox kinetics by forming cooperative interface. As a result, the Li-S cells with the cathodic interlayers obtains a high initial discharge capacity of 1452 mAh g−1 at 0.2 C, superior rate capability up to 2 C rate with a capacity of 952 mAh g−1 and excellent long-term cycling stability by maintaining a low average capacity fading (0.065% per cycle) during 500 cycles at 1 C. Therefore, the interlayer contains MALDH@NPCNFs has extraordinary potential to be used in high-performance Li-S batteries.

Lithiophilic 3D VN@N-rGO as a Multifunctional Interlayer for Dendrite-Free and Ultrastable Lithium-Metal Batteries

It is still a big challenge to effectively suppress dendrite growth, which increases the safety and life of lithium-metal-based high energy/power density batteries. To address such issues, herein we design and fabricate a lithiophilic VN@N-rGO as a multifunctional layer on commercial polypropylene (PP) separator, which is constructed by a thin N-rGO nanosheet-wrapped VN nanosphere with a uniform pore distribution, relatively high lithium ionic conductivity, excellent electrolyte wettability, additional lithium-ion diffusion pathways, high mechanical strength, and reliable thermal stability, which are beneficial to regulate the interfacial lithium ionic flux, resulting in the formation of a stable and homogeneous current density distribution on Li-metal electrodes and hard modified separators that can resist dendrites piercing. Consequently, the growth of Li dendrite is effectively suppressed, and the cycle stability of lithium-metal batteries is significantly improved. In addition, even at a high current density of 10 mA cm-2 and cutoff areal capacity of 5 mAh cm-2, the Li|Li symmetric batteries with VN@N-rGO/PP separators still work very well even over 2500 h, exhibiting ultrahigh cycling stability. This work presents rational design ideas and a facile fabrication strategy of a lithiophilic 3D porous multifunctional interlayer for dendrite-free and ultrastable lithium-metal-based batteries.

Perovskite Quantum Dots as Multifunctional Interlayers in Perovskite Solar Cells with Dopant-Free Organic Hole Transporting Layers.

Perovskite solar cells (PSCs) with organic hole transporting layers (o-HTLs) have been widely studied due to their convenient solution processing, but it remains a big challenge to improve the hole mobilities of commercially available organic hole transporting materials without ion doping while maintaining the stability of PSCs. In this work, we demonstrated that the introduction of perovskite quantum dots (QDs) as interlayers between perovskite layers and dopant-free o-HTLs (P3HT, PTAA, Spiro-OMeTAD) resulted in a significantly enhanced performance of PSCs. The universal role of QDs in improving the efficiency and stability of PSCs was validated, exceeding that of lithium doping. After a deep examination of the mechanism, QD interlayers provided the multifunctional roles as follows: (1) passivating the perovskite surface to reduce the overall amount of trap states; (2) promoting hole extraction from perovskite to dopant-free o-HTLs by forming cascade energy levels; (3) improving hole mobilities of dopant-free o-HTLs by regulating their polymer/molecule orientation. What is more, the thermal/moisture/light stabilities of dopant-free o-HTLs-based PSCs were greatly improved with QD interlayers. Finally, we demonstrated the reliability of the QD interlayers by fabricating large-area solar modules with dopant-free o-HTLs, showing great potential in commercial usage.

Direct coating of multifunctional zinc oxide-reduced graphene oxide interlayer on cathode for lithium-sulfur batteries

In this work, a multifunctional interlayer composed of ZnO nanoparticles (NPs)-reduced graphene oxide (rGO) composite nanosheets was directly coated on the top of sulfur-rGO composite (S-rGO) cathode for the improvement of the electrochemical performances of lithium-sulfur batteries. With this configuration, the rGO network well connecting the interlayer and cathode provides an appropriate electrically conductive pathway for the discharge and charge processes. The soluble lithium polysulfides formed during the discharge process are efficiently absorbed on ZnO NPs to suppress the shuttle effect. In addition, the ZnO NP plays the role of an electrochemical catalyst to accelerate the redox kinetics. With the ZnO-rGO interlayer, the cathode also exhibits the considerably enhanced Li ion transfer/transport properties. The reversible conversion of sulfur to Li2S2/Li2S therefore occurs in the ZnO-rGO interlayer to efficiently reutilize the retained active materials. Moreover, the ZnO-rGO interlayer, which accounts for ~8.5 wt% of the whole cathode, can buffer the volume expansion in the cathode to prevent irreversible structural destruction. Accordingly, a capacity degradation of 0.04% per cycle at 1C after 500 cycles with a capacity retention of 838 mAhg−1 is delivered by S-rGO cathode with the ZnO-rGO interlayer.

Implanting nickel and cobalt phosphide into well-defined carbon nanocages: A synergistic adsorption-electrocatalysis separator mediator for durable high-power Li-S batteries

Transition metal phosphides (TMPs) are proposed as promising polysulfides (LiPSs) mediates with simultaneous strong adsorption and fast conversion capabilities, which is essential for high-energy Lithium-sulfur (Li-S) batteries. Unfortunately, the attempts of using TMPs as sulfur hosts in cathodes suffer from low sulfur loading and poor rate performance. Herein, Ni, Co bimetal phosphides are in-situ implanted into hollow carbon nanocages (Ni-Co-P@C) and utilized as the multifunctional separator interlayer to achieve durable Li-S batteries that can work at high current rates. Benefiting from the unique hollow nanocage and abundant synergistic adsorption-electrocatalytic sites, the Li-S battery with Ni-Co-P@C separator achieves ultrastable lifespan with only 0.056% capacity decay per cycle over 1000 cycles at 0.5 C and superior rate capability of 654.5 mAh g−1 at 5 C. Moreover, the Li-S batteries with a high sulfur loading of 4.5 mg cm−2 can still maintain a high areal capacity of 3.7 mAh cm−2 after 85 cycles. This work demonstrates a new strategy to apply TMPs as a multifunctional mediator in separators for durable high-power Li-S batteries.