Electrochemical Performance Of Battery Research Articles

Rational design of FeF2‐based cathode to realize high‐performance potassium storage

AbstractThe poor electronic conductivity of conversion‐type materials (CMs) and the dissolution/diffusion loss of transition metal (TM) ions in electrodes seriously hinder the practical applications of potassium ion batteries. Simply optimizing the electrode materials or designing the electrode components is no longer effective in improving the performance of CMs. Binders, as one of the electrode components, play a vital role in improving the electrochemical performance of batteries. Here we rationally designed FeF2 electrodes for the first time by optimizing electrode materials with the introduction of carbon nanotubes (CNTs) and combined with a sodium alginate (SA) binder based on strong interactions. We show that the FeF2@CNTs‐SA cathode does not suffer from TM ion dissolution and delivers a high capacity of 184.7 mAh g−1 at 10 mA g−1. Moreover, the capacity of FeF2@CNTs‐SA is as high as 99.2 mAh g−1 after 100 cycles at 100 mA g−1, which is a twofold increase compared to FeF2@CNTs‐PVDF. After calculating the average capacity decay rate per cycle of them, we find that FeF2@CNTs‐SA is about one‐third lower than FeF2@CNTs‐PVDF. Therefore, the SA binder can be broadly used for electrodes comprising several CMs, providing meaningful insights into mechanisms that lead to their improved electrochemical performances.

Optimizing HDPE separator properties through thermoplastic elastomer loading and manufacturing process for improved lithium-ion battery electrochemical performance

Optimizing HDPE separator properties through thermoplastic elastomer loading and manufacturing process for improved lithium-ion battery electrochemical performance

Heteroatom Immobilization Engineering toward High-Performance Metal Anodes.

Heteroatom immobilization engineering (HAIE) is becoming a forefront approach in materials science and engineering, focusing on the precise control and manipulation of atomic-level interactions within heterogeneous systems. HAIE has emerged as an efficient strategy to fabricate single-atom sites for enhancing the performance of metal-based batteries. Despite the significant progress achieved through HAIE in metal anodes for metal-based batteries, several critical challenges such as metal dendrites, side reactions, and sluggish reaction kinetics are still present. In this review, we delve into the fundamental principles underlying heteroatom immobilization engineering in metal anodes, aiming to elucidate its role in enhancing the electrochemical performance in batteries. We systematically investigate how HAIE facilitates uniform nucleation of metal in anodes, how HAIE inhibits side reactions at the metal anode-electrolyte interface, and the role of HAIE in promoting the desolvation of metal ions and accelerating reaction kinetics within metal-based batteries. Finally, we discuss various strategies for implementing HAIE in electrode materials, such as high-temperature pyrolysis, vacancy reduction, and molten-salt etching and anchoring. These strategies include selecting appropriate heteroatoms, optimizing immobilization methods, and constructing material architectures. They can be utilized to further refine the performance to enhance the capabilities of HAIE and facilitate its widespread application in next-generation metal-based battery technologies.

Design and Preparation of One-Dimensional Cathode By Electrophoretic Deposition Method for Flexible Knitted Batteries

Rechargeable batteries are highly promising energy storage systems that can convert and store electrical energy. Effective energy storage systems should have high energy density, high power, safety, environmentally friendliness, and long cycle life. To meet the aforementioned objectives, researchers have attempted to use different morphologies of nanomaterials as electrodes to improve the electrochemical performance of batteries. Among the materials available, one-dimensional structures have unique properties over traditional ones and extensive applications in wearable devices due to their flexibility [1]. Flexible batteries have several advantages such as mechanical flexibility, good energy storage capabilities, affordability, and environmental safety [2]. They knitted or sewed into textiles, folded into random forms, and wrapped around body parts like the neck or wrist [3]. However, there is little research that covers Li-ion batteries that have a one-dimensional flexible structure.Achieving simultaneous high electronic/ionic conductivity and electrochemical stability is difficult in a homogeneous single-component electrode material. Consequently, the development of precisely defined functional one-dimensional (1D) hetero-nanostructures that effectively integrate the advantages and address the limitations of various electrochemically active materials becomes critical [1].The proposed methodology involves the electrophoretic deposition of lithium iron phosphate on conductive nickel wire, providing a one-dimensional cathode structure. As an anode, nickel-tin is deposited on nickel wire by electrochemical deposition. The deposition method allows greater precision and control over the deposition of active material on the current collector and also has possible applications on different structures such as 1D and 3D. Also, the electrolyte was obtained by layer-by-layer method, by dipping the cathode and anode, separately, in polymers to coat the cathode material as an electrolyte-separator film. The full cell was assembled and the better results will be presented in the meeting. Acknowledgments This research was funded by the Science Committee of the Ministry of Education and Science of the Republic of Kazakhstan (Grant No. АР19679855).

Thermal Runaway Characteristics of Ni-Rich Lithium-Ion Batteries Employing Triphenyl Phosphate-Based Electrolytes

Abstract Enhancing the safety performance of high-energy-density lithium-ion batteries is crucial for their widespread adoption. Herein, a cost-effective and highly efficient electrolyte additive, triphenyl phosphate (TPP), demonstrates flame-retardant properties by scavenging hydrogen radicals in the flame, thereby inhibiting chain reactions and flame propagation to enhance the safety performance of graphite/LiNi0.8Co0.1Mn0.1O2 (Gr/NCM811) pouch cells. The results reveal that the capacity retention of cells without flame retardants, and those with the addition of 1 wt%, 3 wt%, 5 wt%, and 10 wt% TPP is 96.4%, 92.1%, 84.15%, 40.8%, and 12.4% (at 1/2C 300 cycles), respectively. Furthermore, compared to cells without flame retardants, the highest temperature during thermal runaway (TR) decreases by 8.3%, 26.9%, 35.1%, and 38.8% with the addition of 1 wt%, 3 wt%, 5 wt%, and 10 wt% TPP, respectively. Through comprehensive analysis of the impact of flame-retardant additives on battery electrochemical performance and safety, it is determined that the optimal addition amount is 3 wt%. At this level, there are no significant flames during battery abuse, the triggering temperature for TR increases by 26.6 ℃, and the maximum temperature decreases by 157 ℃. Moreover, even after 300 cycles at 1/2C, a capacity of 814.5 mAh is retained, with a capacity retention rate of 84.1%. This study provides valuable insights into mitigating TR in high-energy-density power batteries.

Tailoring Interfacial Structures to Regulate Carrier Transport in Solid-State Batteries.

Solid-state lithium-ion batteries (SSLIBs) have been considered as the priority candidate for next-generation energy storage system, due to their advantages in safety and energy density compare with conventional liquid electrolyte systems. However, the introduction of numerous solid-solid interfaces results in a series of issues, hindering the further development of SSLIBs. Therefore, a thorough understanding on the interfacial issues is essential to promote the practical applications for SSLIBs. In this review, the interface issues are discussed from the perspective of transportation mechanism of electrons and lithium ions, including internal interfaces within cathode/anode composites and solid electrolytes (SEs), as well as the apparent electrode/SEs interfaces. The corresponding interface modification strategies, such as passivation layer design, conductive binders, and thermal sintering methods, are comprehensively summarized. Through establishing the correlation between carrier transport network and corresponding battery electrochemical performance, the design principles for achieving a selective carrier transport network are systematically elucidated. Additionally, the future challenges are speculated and research directions in tailoring interfacial structure for SSLIBs. By providing the insightful review and outlook on interfacial charge transfer, the industrialization of SSLIBs are aimed to promoted.

Photothermal Enhancement of Prussian Blue Cathodes for Li-Ion Batteries.

Photoenhanced batteries, where light improves the electrochemical performance of batteries, have gained much interest. Recent reports suggest that light-to-heat conversion can also play an important role. In this work, we study Prussian blue analogues (PBAs), which are known to have a high photothermal heating efficiency and can be used as cathodes for Li-ion batteries. PBAs were synthesized directly on a carbon collector electrode and tested under different thermally controlled conditions to show the effect of photothermal heating on battery performance. Our PBA electrodes reach temperatures that are 14% higher than reference electrodes using a blue LED, and a capacity enhancement of 38% was achieved at a current density of 1600 mA g-1. Additionally, these batteries show excellent cycling stability with a capacity retention of 96.6% in dark conditions and 94.8% in light over 100 cycles. Overall, this work shows new insights into the effects leading to improved battery performance in photobatteries.

Developing a Multifunctional Cathode for Photoassisted Lithium-Sulfur Battery.

Integration of solar cell and secondary battery cannot only promote solar energy application but also improve the electrochemical performance of battery. Lithium-sulfur battery (LSB) is an ideal candidate for photoassisted batteries owing to its high theoretical capacity. Unfortunately, the researches related the combination of solar energy and LSB are relatively lacking. Herein, a freestanding photoelectrode is developed for photoassisted lithium-sulfur battery (PALSB) by constructing a heterogeneous structured Au@N-TiO2 on carbon cloths (Au@N-TiO2/CC), which combines multiple advantages. The Au@N-TiO2/CC photoelectrode can produce the photoelectrons to facilitate sulfur reduction during discharge process, while generating holes to accelerate sulfur evolution during charge process, improving the kinetics of electrochemical reactions. Meanwhile, Au@N-TiO2/CC can work as an electrocatalyst to promote the conversion of intermediate polysulfides during charge/discharge process, mitigating induced side reactions. Benefiting from the synergistic effect of electrocatalysis and photocatalysis, PALSB assembled with an Au@N-TiO2/CC photoelectrode obtains ultrahigh specific capacity, excellent rate performance, and outstanding cycling performance. What is more, the Au@N-TiO2/CC assembled PALSB can be directly charged under light illumination. This work not only expands the application of solar energy but also provides a new insight to develop advanced LSBs.

Construction of an Ohmic Contact Cathode by Two Metal Sulfides for efficient Capture and Catalysis of Polysulfide.

The slow reaction kinetics and severe shuttle effect of lithium polysulfide make Li-S battery electrochemical performance difficult to meet the demands of large electronic devices such as electric vehicles. Based on this, an electrocatalyst constructed by metal phase material (MoS2) and semiconductor phase material (SnS2) with ohmic contact is designed for inhibiting the dissolution of lithium polysulfide with improving the reaction kinetics. According to the density-functional theory calculations, it is found that the heterostructured samples with ohmic contacts can effectively reduce the reaction-free energy of lithium polysulfide to accelerate the sulfur redox reaction, in addition to the excellent electron conduction to reduce the overall activation energy. The metallic sulfide can add more sulfophilic sites to promote the capture of polysulfide. Thanks to the ohmic contact design, the carbon nanotube-MoS2-SnS2 achieved a specific capacity of 1437.2 mAhg-1 at 0.1 C current density and 805.5 mAhg-1 after 500 cycles at 1 C current density and is also tested as a pouch cell, which proves to be valuable for practical applications. This work provides a new idea for designing an advanced and efficient polysulfide catalyst based on ohmic contact.

Tailoring amino-functionalized cellulose separators for improved lithium-ion battery performance

This study aims to enhance cellulose separators for energy storage, focusing on achieving high security and superior electrolyte wetting properties. Bacterial cellulose (BC) separators were initially prepared via vacuum filtration. Subsequently, carboxymethyl cellulose (CMC) underwent amino-functionalization by successfully cross-linking polyethyleneimine (PEI) using glutaraldehyde. The amino-functionalized CMC was then composited onto the BC separator. This composite separator demonstrated excellent thermal stability at 200 °C and favorable electrolyte wetting. The amino groups in PEI enhanced Li+ migration by forming hydrogen bonds with PF6− in the electrolyte. Additionally, molecular-level hydrogen bonding between amino groups on PEI and carboxyl/hydroxyl groups in CMC regulated the separator's porosity. The abundant carboxyl groups in CMC facilitated Li+ transfer, notably boosting the lithium-ion battery's electrochemical performance. After 90 charge and discharge cycles, the discharge capacity of the battery assembled with BC/CMC-PEI composite separator is 132.8 mAh/g, which is 25.1 % higher than the 106.1 mAh/g of the battery assembled with traditional PP separator. At a current density of 2C, the minimum discharge capacity of the battery assembled with the composite separator is 71.1 mAh/g, while the minimum discharge capacity of the battery assembled with the PP separator is 53.6 mAh/g. This approach using functional group modification provides a promising approach to improving the performance of lithium-ion batteries.

Solvation Effect: The Cornerstone of High-Performance Battery Design for Commercialization-Driven Sodium Batteries.

Sodium batteries (SBs) emerge as a potential candidate for large-scale energy storage and have become a hot topic in the past few decades. In the previous researches on electrolyte, designing electrolytes with the solvation theory has been the most promising direction is to improve the electrochemical performance of batteries through solvation theory. In general, the four essential factors for the commercial application of SBs, which are cost, low temperature performance, fast charge performance and safety. The solvent structure has significant impact on commercial applications. But so far, the solvation design of electrolyte and the practical application of sodium batteries have not been comprehensively summarized. This review first clarifies the process of Na+ solvation and the strategies for adjusting Na+ solvation. It is worth noting that the relationship between solvation theory and interface theory is pointed out. The cost, low temperature, fast charging, and safety issues of solvation are systematically summarized. The importance of the de-solvation step in low temperature and fast charging application is emphasized to help select better electrolytes for specific applications. Finally, new insights and potential solutions for electrolytes solvation related to SBs are proposed to stimulate revolutionary electrolyte chemistry for next generation SBs.

Electrolyte Design Chart Reframed by Intermolecular Interactions for High-Performance Li-Ion Batteries.

Developing advanced electrolytes has been regarded as a pivotal strategy for enhancing the electrochemical performance of batteries; however, the criteria for electrolyte design remain elusive. In this study, we present an electrolyte design chart reframed through intermolecular interactions. By combining systematic nuclear magnetic resonance, Fourier transform infrared measurements, molecular dynamics (MD) simulations, and machine-learning-assisted classifications, we establish semiquantitative correlations between electrolyte components and the electrochemical reversibility of electrolytes. We propose the equivalent increment of Li salt resulting from functional cosolvent and solvent-solvent interactions for effective electrolyte design and prediction. The controllable regulation of the electrolyte design chart by the properties of solvent-solvent interactions presents varying equivalent effects of increasing Li salt concentrations in different electrolyte systems. Based on this mechanism, we demonstrate highly reversible and nonflammable phosphate-based electrolytes for graphite||NCM811 full cells. The proposed electrolyte design chart, semiquantitatively determined by intermolecular interactions, provides the necessary experimental foundation and basis for the future rapid screening and prediction of electrolytes using machine-learning methods.

Dual-gate design enables intrinsic safety of high-energy batteries

The safety issue hampers the application of high-energy lithium-ion batteries in electric vehicles, grid energy storage, electric ships and aircrafts. The chemical cross-talk, which refers to the migration of energetic intermediates between cathode and anode, initiates battery self-heating and accelerates the intensive heat release during battery thermal failure. However, blocking the chemical cross-talk is extremely hard. Previously, we may expect a thermally stable separator can guard the gate between battery cathode and anode, however, large amount of hot gas breaks the defense mechanically not thermally. Draining the cross-talk gas is of equal importance with blocking it. Herein, a dual-gate design notion is proposed, using separator as “block gate” and vent valve as “removal gate” to regulate the spatial distribution of energetic species to reduce the major heat release during battery thermal runaway. The design is validated by more than 50 battery chemistries. Typically, the maximum temperature of NMC811||Gr pouch cell decreases from >800 °C to <300 °C, the highest temperature rising rate decreases from 761.0 °C/s to 0.013 °C/s. The morphology and crystalline change of cathode verify that the chemical cross-talk is successfully suppressed. Moreover, such design has little side effect on the electrochemical performance of batteries. The dual-gate design breaks the bottleneck for the safety design of high energy batteries, providing insight into the safe utilization of electrochemical energy storage materials.

3D Morphological Evolution of Dead and Active Lithium at the Graphite-Separator-Electrolyte Interface during Fast Charging

Lithium-ion batteries (LIBs) have profoundly advanced the development of electric vehicles (EV). However, one of the remaining bottlenecks in the widespread adoption of EVs is the long charging time required for commercial LIBs. There is a global push towards extreme fast charging (XFC) to reduce charging times to 10-15 minutes.1 However, XFC results in rapid degradation in the electrochemical performance of batteries, mainly due to Li plating. This plating refers to the loss of active Li, where it either becomes dead meaning electronically disconnected after plating on the anode, or it becomes inactive due to the irreversible reaction of Li with the electrolyte to form a solid electrolyte interphase. Dead Li contributes significantly to capacity loss during XFC;3 thus, differentiating dead and inactive from active Li is extremely important to unravel their link with battery capacity fade. However, owing to the complexity of these competing electrochemical reactions in addition to the intricacy of detecting Li at the buried graphite-separator-electrolyte interface, a comprehensive understanding of Li plating remains a challenge.In this work, we conducted non-destructive, in-situ three-dimensional (3D) characterization of dead and active Li on energy-dense graphite electrodes during XFC using high-resolution neutron micro-computed tomography (µCT). Thick or industry-relevant (negative and positive electrodes ~ 130 μm) graphite electrodes are promising battery materials because they store higher amounts of energy. However, they plate Li faster and at lower XFC cycle numbers, and hence experience higher loss in battery capacity due to Li plating.To characterize Li plating on thick graphite electrodes, we performed high-resolution neutron µCT4 (pixel size: ~ 5.74 µm; effective spatial resolution: ~10-15 µm) at the ICON beamline5 at the Swiss Spallation Neutron Source at the Paul Scherrer Institute. Neutron µCT was used because it provides high relative neutron contrast between Li and C (~ 71.87: 5.55 barns6) for in-situ 3D imaging. Therefore, to leverage high-resolution neutron µCT for in-situ Li detection, we designed a neutron-friendly LIB. Our designed battery enabled excellent neutron transmission at the graphite-separator-electrolyte interface while exhibiting similar XFC performance at a 6C charging-rate between 3.0 and 4.1V. We imaged three batteries in the charged and discharged states under the following conditions: 4 cycles at 1C charging; 4 and 6 cycles at 6C charging. Here, we note that since inactive Li was below the spatial resolution of the ICON beamline, only dead, active, and plated Li were investigated in this work.Our results reveal changes in dead Li morphologies from isolated deposits after 4 cycles at 1C charging to increasingly mossy-like dense deposits covering the entire circumference of the graphite electrode after 6 cycles at 6C charging. Furthermore, as the XFC cycle number increased from four to six at 6C charging, the amount of dead Li increased significantly. After 6 cycles at 6C charging, we also observed dead Li outgrowths in a circular geometry onto the separator around the graphite electrode. Using our imaging data, we determined a quantitative link between the amounts of dead and active Li with the capacity loss of the battery. Our analysis suggests that the amounts of plated and dead Li increase with the charging rate and cycle number. Finally, we developed quantitative relationships in 3D between the amounts of dead, active, and plated Li, and XFC-related capacity loss of the battery.In conclusion, this work contributed to the advanced understanding of the morphological evolution of dead, active, and plated Li and their relationship with XFC-related capacity loss on thick graphite electrodes. We believe these insights will help inform rational 3D designs of thick graphite electrodes that will minimize Li plating in fast-charged LIBs.

Effect of electrolyte additives derived from natural plant extracts - Hibiscus Sabdariffa &Bidens Pilosa, on electrochemical performance of a lead-acid battery

Lead-Acid Batteries (LABs) remain a popular choice for energy storage due to their wide availability and reasonably low cost, but they exhibit a shorter cycle life and are non-eco-friendly. The objective of this study was to evaluate the discharge capacity of a flooded lead-acid battery using an electrolyte modifiedwith additives from natural plant extracts -Hibiscus Sabdariffa (H–S) and Bidens Pilosa (B–P) plants. The study utilized commercial LABs with electrolyte solutions of 100% sulfuric acid and varying volumes of plant extract solutions at concentration of 10% (w/v), 15.86% (w/v), 30% (w/v) and 44.14% (w/v). The effect of the additives was assessed by comparing the charge-discharge cycle times, coulombic efficiency and energy efficiency. The results show the longest measured discharge time of 4.63 h at 15.86% (w/v) of H–S additive-electrolyte solution, 0.13 h longer than for the standard electrolyte. The highest coulombic efficiency (CE) was 97.3% at 44.14% (w/v) of H–S additive electrolyte solution, 10% above the standard electrolyte. The highest value for energy efficiency (EF) was 83.8% achieved in the battery with 44.14% (w/v) H–S additive electrolyte solution. The best recorded performance with B–P additive electrolyte solution was, CE of 94.6% and EF of 81.3%, obtained at 15.86% (w/v) additive concentration. It is evident from the results that bio-active compounds present in the additive solution of plant extracts influenced the electrochemical performance of the battery. The novelty of this work lies in the choice of candidate plants named, H–S and B–P for green extracts and the methodology of extraction, which is low-cost, eco-friendly and sustainable. This study contributes to fundamental understanding and strategies towards economical and eco-friendly plant electrolyte batteries.

Covalent Organic Frameworks (COFs): Characteristics and Applications for Lithium-Ion Batteries (LIBs) and Sodium Ion Batteries (SIBs)

Covalent organic frameworks (COFs) belong to a family of porous organic materials that form 2D or 3D tuned structures via a covalent bond formation between organic blocks. COFs exhibit a remarkable array of characteristics that make them highly promising materials for various applications. COFs are characterized by their chemical and physical stability, their highly porous structure, and their easy structural tunability. They emerged as promising candidates for electrode materials in advanced energy storage devices such as sodium-ion batteries (SIBs) and lithium-ion batteries (LIBs). COFs can be precisely customized for each application via pore engineering and framework functionalization as well as the pre- and post-synthesis. Research has been conducted to examine the effect of various functional groups, active redox sites, pore size, and interlayer distances on the performance of COFs as electrode materials. Herein, this review reports the most recent advances in using COFs as electrode materials in both LIBs and SIBs. It also discusses the synthesis of COFs, structural engineering, and pore engineering. The main advantages and challenges that arise with the application of COFs in rechargeable batteries are presented. This review concluded that COFs do have the potential as anode materials in both LIBs and SIBs by virtue of their crystalline structure and high porosity that enable efficient ion diffusion and storage. COFs provided enhanced battery electrochemical performance, improved energy density, and prolonged cycle life.

Recent advances in metal-organic frameworks for electrochemical performance of batteries

Recent advances in metal-organic frameworks for electrochemical performance of batteries

Reduced graphene oxide coated with amorphous lead as positive additive for enhanced performance of lead–carbon batteries

Composites of reduced graphene oxide coated with amorphous lead (Pb/rGO) were prepared by electrostatic adsorption and hydrothermal methods, and used as positive additives for lead–carbon batteries to enhance discharge specific capacity and cycle life under high-rate partial-state-of-charge (HRPSoC) of batteries. Amorphous Pb inhibits the oxygen evolution reaction (OER) that occurs on the surface of reduced graphene oxide (rGO) and increases the specific capacitance of the positive active material (PAM). In addition, the presence of amorphous Pb enhances the affinity of rGO to PAM, which avoids the separation of additive and PAM during the cycling process. Pb/rGO additives can act as pore forming agents and significantly increase the specific surface area of PAM, which enables the electrolyte to fully react with PAM to inhibit the overgrowth of PbSO4 crystals. Thus, Pb/rGO additives help to improve the electrochemical performance of batteries. To be specific, when the Pb/rGO additive content is 0.7 wt%, battery showed the best discharge specific capacity (102 mAh/g) and cycle life (18,104 cycles), which is 117% and 104% higher than that of blank battery, respectively. And the rate capability is also improved compared to its counterpart. In short, the Pb/rGO composite material has potential application value in lead–carbon batteries.

Towards stable electrode–electrolyte interphases: Regulating solvation structures in electrolytes for rechargeable batteries

AbstractRechargeable batteries are highly in demand to power various electronic devices and future smart electric grid energy storage. The electrode–electrolyte interphases play a crucial role in influencing the electrochemical performance of batteries, with the solvation chemistries of the electrolyte being particularly significant in regulating these interfacial reactions. However, the reaction mechanisms of electrolyte solvation and their specific functions in batteries are not yet fully understood. In this review, we embark on an exploration of the fundamental principles governing solvation and present a comprehensive overview of how solvation structures impact interfacial reactions at the electrode–electrolyte interface. We underscore the significance of interactions among cations, anions, and solvents in shaping electrolyte solvation structures. The primary strategies for controlling solvation structures are also discussed, including the optimization of salt concentrations, solvent interactions, and the introduction of functional cosolvents. Furthermore, we elucidate the oxidation/reduction reaction mechanisms of electrolyte components in different solvation structures and the new understanding of electrolyte additives in modulating interfacial chemistries in batteries. Additionally, we emphasize the importance of incorporating new characterization techniques and theoretical simulations to attain a deeper understanding of the intricate processes taking place within batteries. This review provides an in‐depth understanding in solvations and interphasial properties and new ideas for designing advanced functional electrolytes for rechargeable batteries.

Molecular engineering of N-rich ZIF-integrated graphene composite interface for efficient physiochemical confinement and catalytic conversion of polysulfides in lithium–sulfur batteries

Lithium–sulfur (Li–S) batteries are regarded as one of the most promising energy storage systems because of their high theoretical specific capacity, energy density, low cost, and environmental benignancy. However, the practical application of Li–S batteries has been hindered by inevitable polysulfides shuttling behavior, the sluggish redox kinetics, and poor electrical conductivity of sulfur, which lead to rapid capacity decay and low active material utilization. In this study, we report a multifunctional layer consisting of N-rich zeolitic imidazolate frameworks (ZIF)/reduced graphene oxide (rGO) composite (NZG) as an electrocatalyst to overcome the drawbacks of Li–S batteries. During the preparation of NZG, deamination of the ZIF8A induces the incorporation of abundant N-containing moieties into rGO (pyridinic and pyrrolic N), which results in providing favorable active sites for polysulfides confinement and their rapid conversion via physiochemical interactions. Additionally, hierarchical pores with large surface area and interconnected conductive pathways in the as-prepared multifunctional layer accelerate the catalytic conversion kinetics of polysulfide species, leading to high sulfur utilization and enhanced Li–S battery electrochemical performance. This work suggests an efficient approach for designing multifunctional layers to achieve high-performance Li–S batteries.