High Capacity Density Research Articles

Progress of silicon and graphene composites in lithium-ion battery anodes

As society progresses, the need for high-power, long-life energy supply devices gradually increases. Lithium-ion batteries (LIBs) with large energy reserves and high power have recently become the preferred choice. The anode of LIBs plays a crucial role in battery performance, safety, and cycle life. Typically, graphite materials are used for LIBs anodes. Still, they have drawbacks such as low first-time Coulombic efficiency, capacity degradation, safety issues, short cycle life, insufficient gram capacity, and purity and side reactions, which limit the application of LIBs. Therefore, new harmful electrode materials are in demand. Graphene and silicon are both environmentally friendly and sustainable materials. They both have the advantages of high theoretical capacity and high energy density, which are critical materials for developing LIBs. Combining the two can exert a synergistic effect and jointly improve the cycle stability of the battery. In this paper, we review the preparation methods of graphene and silicon composites in recent years, including mechanical ball milling and hydrothermal and thermal reduction methods. In addition, graphene and silicon composites have been explored for LIBs applications.

Novel electriferous charge-mosaic S(TMC@Lys-Li) separator towards efficient Li+ fast-transfer for high-energy density and long-duration lithium-sulfur batteries

Lithium-sulfur (Li-S) batteries with attractive capacity give remarkable potential for prospective high-capacity application scenarios but suffer a fatal flaw of short cyclability before large-scale commercialization especially owing to polysulfide (Li2Sn) transmembrane shuttling. To efficiently restrain chronic Li2Sn shuttle and expedite Li+ transfer, herein, a novel electriferous charge-mosaic S(TMC@Lys-Li) separator preparation approach is recommended. Interfacial polymerizations of lithiated lysine and trimesoyl chloride establish an electriferous charge-mosaic polyamide functional layer. Substituted Li within the charge-mosaic layer offers transition or replacement sites for smoothing Li+ migrations, which constructs efficient Li+ fast-transfer private channels and accelerates the Li+ transfer rate to 9.4 times. Negatively charged polyamide skeleton synchronously heightens Li2Sn rejections by combining Donnan and steric effects. S(TMC@Lys-Li) replenishes Li for homogenizing Li nucleation and growth, endowing stable plating/stripping behaviors over 250 cycles for Li-Cu batteries. Assembled Li-S cells thus exhibit excellent specific capacity and cyclability at multiple application scenarios such as long periods, high areal capacity, and fast charge, holding 78.1% retention after 500 cycles at 1 C. The superior thermal stability and self-discharge of S(TMC@Lys-Li) dramatically strengthen battery thermal runaway resistance even at 155 ℃, which ensures security for Li-S battery high-power and high-temperature operations. Above alluring features enable charge-mosaic separators to be potentially adopted in practical Li-S batteries demanding strict security, high-capacity density, and fast charge technology.

Dual-Functional SnO2-CNT-PANI||PP||SnO2 Separator for Enhanced Lithium-Sulfur Battery Stability and Capacity

Lithium-sulfur batteries (LSBs) provide high capacity and energy density for advanced energy storage but encounter performance and safety issues due to lithium polysulfides (LiPSs) dissolution and dendrite formation. This study introduces a dual-functional SnO2-CNT-PANI||PP||SnO2 separator (DF-SNCPS) aimed at improving the stability and safety of LSBs. The separator includes a SnO2-CNT-PANI layer on the sulfur cathode side for enhanced electrical conductivity and polysulfide adsorption and a SnO2 nanoparticle (nano-SnO2) layer on the lithium anode side to regulate lithium-ion concentration and inhibit dendrite growth. Density functional theory (DFT) and the phase field method have verified the relevant material's catalytic performance and dendrite suppression ability. These methods have provided a comprehensive understanding of the underlying mechanisms, providing auxiliary explanations for their role in catalyzing polysulfide conversion and suppressing lithium dendrite growth. This innovative design mitigates the shuttle effect and enhances cyclic stability and sulfur utilization, achieving a notable cyclic performance with a capacity retention of 0.05% per cycle over 800 cycles at 1C. The synergistic effects of the modified separator present a viable pathway for LSB commercialization.

Review on polymer electrolytes for lithium‐sulfurized polyacrylonitrile batteries

AbstractLithium‐sulfur (Li‐S) batteries are deemed as the next generation of energy storage devices due to high theoretical specific capacity (1675 mAh g−1) and energy density (2600 Wh kg−1). However, the commercial application has always been constrained by lithium polysulfide (LiPSs) shuttling effects and still has a long way to go. Sulfurized polyacrylonitrile (SPAN) is a promising alternative candidate to replace traditional sulfur cathode and is conducive to eliminating LiPSs by realizing “solid‐solid” direct conversion in conventional carbonate electrolytes. However, an over 25% irreversible capacity loss is exhibited inevitably in the first discharge process, the inherent structure of SPAN and the related reaction mechanism remain unclear. In this review, the structure characteristics and electrochemical behaviors of SPAN are summarized for better interpreting current knowledge and favoring the design of high performance materials. In the past few decades, many problems in traditional Li‐S batteries have been solved by improving electrolytes. Polymer electrolytes (PEs) have been widely used due to structural designability, multi‐functionality, exceptional chemical stability, and excellent processability. Surprisingly, the relevant researches on PEs compatible with SPAN remains limited currently. Therefore, the recent modification strategies of gel polymer electrolytes and solid polymer electrolytes in Li‐SPAN batteries are introduced in terms of Li+ transfer and interface engineering, the design principles are concluded, the specific challenges encountered by polymer‐based electrolytes are summarized and the instructive directions for future research on PEs are demonstrated, facilitating the commercialization of Li‐SPAN batteries.

Solid‐State Electrolytes for Lithium‐Air Batteries

Li‐air batteries (LABs) have attracted widespread attention due to their extremely high theoretical capacity and energy density. However, liquid LABs face safety issues such as flammability and leakage, which hinder their practical application. In comparison, solid‐state electrolytes (SSEs) possess excellent mechanical strength, good chemical stability, a wide electrochemical window, and non‐flammable characteristics, offering a feasible strategy for achieving stable and practical LABs. In this review, we will focus on the development and challenges of different kinds of SSEs, further their interfacial issues with electrodes, and finally propose strategies and outlooks for advanced solid‐state lithium‐air batteries (SSLABs). It is expected that this review will provide a systematic understanding and theoretical guidance for design of high‐performance SSLABs.

Stabilizing zinc anodes by a solvation sheath modification with toluenesulfonate additive

As an advanced electrochemical energy storage device, aqueous zinc-ion batteries offer high theoretical capacity and energy density, employing water-based electrolytes to reduce fire and explosion risks. However, zinc tends to form dendrites during charge-discharge processes, leading to reduced electrode surface area and shortened cycling lifespan. In this study, we propose the use of a commonly used and cost-effective additive, sodium p-toluenesulfonate (OTM), to stabilize zinc anodes. Experimental and theoretical simulations demonstrate that OTM can enter the solvation sheath of Zn2+, reduce the activity of nearby H2O molecules, facilitate uniform Zn2+ deposition, and suppress zinc dendrite formation. Therefore, Zn//Zn symmetric batteries utilizing ZnSO4 (ZSO) electrolytes containing OTM achieved outstanding long-term performance exceeding 1700 h at 1 mA cm−2, significantly surpassing those employing ZSO electrolytes. Additionally, Zn//VO2 full batteries with OTM additives exhibited enhanced cycling stability and an initial discharge capacity of 180 mAh g−1 at 3 A g−1, demonstrating its superior application potential.

Optimization of electrode thickness of lithium-ion batteries for maximizing energy density

AbstractThe demand for high capacity and high energy density lithium-ion batteries (LIBs) has drastically increased nowadays. One way of meeting that rising demand is to design LIBs with thicker electrodes. Increasing electrode thickness can enhance the energy density of LIBs at the cell level by reducing the ratio of inactive materials in the cell. However, after a certain value of electrode thickness, the rate of energy density increase becomes slower. On the other hand, the impact of associated limitations becomes stronger, reducing the practical applicability of LIBs with thicker electrodes. Hence, an optimum value of thickness is of utmost importance for the practicability of thicker electrode design. In this paper, both the cathode thickness and the anode thickness of an NCM LIB cell were optimized by applying response surface methodology (RSM) with a Box-Behnken design (BBD) to maximize the energy density. Moreover, the influence of electrode porosity, together with the interaction of porosity with cathode and anode thickness, was incorporated into the optimization. A full factorial design of 3-level, 3-factor was used to generate 15 simulation conditions in accordance with the design of experiment (DoE) achieved through BBD. Then, those conditions were used to achieve 15 responses by simulating a reduced-order electrochemical model. Finally, the statistical technique analysis of variance (ANOVA) was used to analyze and validate the results of RSM. The results show that the RSM-BBD optimization method, coupled with ANOVA, has successfully optimized the thicknesses of both positive and negative electrodes for maximum energy density, despite the nonlinearity of the electrochemical system. The findings suggest an optimized cathode thickness of 401.56 µm and anode thickness of 186.36 µm for a maximum energy density of 292.22 of an NCM LIB cell, while electrode porosity is preferred to be 0.2.

Revitalizing Lithium Metal Batteries: Strategies for Tackling Dead Lithium Formation and Reactivation.

Lithium (Li) metal batteries (LMBs) are among the most promising candidates for future battery technology due to their high theoretical capacity and energy density. However, the formation of dendritic Li, characterized by needle-like structures, poses serious safety issues. To address this, numerous methods are developed to prevent Li dendrite formation. Another significant challenge in LMBs is the formation of inactive Li, known as dead Li, which significantly impacts their Coulombic efficiency and overall performance. This review explores the issues surrounding dead Li in LMBs, specifically focusing on electrically isolated Li metal and the repeatedly generated solid electrolyte interphase (SEI). Advanced techniques for characterizing inactive Li are discussed, alongside various strategies designed to activate or suppress dead Li, thus restoring battery capacity. The review summarizes recent advancements in research related to the activation, reuse, and prevention of dead Li, offering valuable insights for enhancing the efficiency and safety of LMBs. This comprehensive overview provides fundamental guidance for the practical application of Li metal anodes and similar metal batteries.

Silicon-air batteries enabled by in-situ FeMn alloy-catalyzed nitrogen-doped carbon nanotube arrays as efficient air electrodes catalysts

Silicon-air batteries (SABs) have become promising candidates for energy conversion and storage devices due to their high theoretical energy density, cost-effectiveness, and inherent safety. However, the slow kinetics of the 4e− transfer in the oxygen reduction reaction (ORR) at the cathode during discharge, coupled with severe polarization, reduces the battery’s capacity and hinders the development of silicon-air batteries. The cathodes of currently developed SABs primarily rely on commercial Pt/C and MnO2, with limited research on low-cost, efficient, and stable air cathodes for SABs. To address this issue, we synthesized nitrogen-doped carbon nanotubes containing FeMn alloy particles (FeMn@NCNTs) as cathode ORR catalysts using a simple high-temperature pyrolysis method combined with chemical vapor deposition. In an alkaline medium, the catalyst’s half-wave potential (E1/2) reached 0.83 V. Moreover, the FeMn@NCNTs air cathode exhibited excellent compatibility with the silicon anode, and the constructed aqueous silicon-air battery demonstrated a high specific capacity (165 Ah kg−1) and power density (3.69 mW cm−2). Additionally, the quasi-solid-state SABs constructed with FeMn@NCNTs showed stable operation over a wide temperature range, providing a new solution for the development of low-cost, efficient silicon-air batteries suitable for a wide range of applications.

Exploring the Mechanisms of LiNiO2 Cathode Degradation by the Electrolyte Interfacial Deprotonation Reaction.

Nickel-rich layered oxides stand as ideal cathode candidates for high specific capacity and energy density next-generation lithium-ion batteries. However, increasing the Ni content significantly exacerbates structural degradation under high operating voltage, which greatly restricts large-scale commercialization. While strategies are being developed to improve cathode material stability, little is known about the effects of electrolyte-electrode interaction on the structural changes of cathode materials. Here, using LiNiO2 in contact with electrolytes with different proton-generating levels as model systems, we present a holistic picture of proton-induced structural degradation of LiNiO2. Through ab initio molecular dynamics calculations based on density functional theory, we investigated the mechanisms of electrolyte deprotonation, protonation-induced Ni dissolution, and cathode degradation and the impacts of dissolved Ni on the Li metal anode surfaces. We show that the proton-transfer reaction from electrolytes to cathode surfaces leads to dissolution of Ni cations in the form of NiOOHx, which stimulates cation mixing and oxygen loss in the lattice accelerating its layered-spinel-rock-salt phase transition. Migration of dissolved Ni2+ ions to the anode side causes their reduction into the metallic state and surface deposition. This work reveals that interactions between the electrolyte and cathode that result in protonation can be a dominant factor for the structural stability of Ni-rich cathodes. Considering this factor in electrolyte design should be of benefit for the development of future batteries.

Nano-necklace Co/β-Mo2C hetero-nanodots encapsulating into carbon nanotubes with strong adsorption and catalytic conversion of polysulfides for lithium‑sulfur batteries separator

Due to their high theoretical capacity and high energy density, Lithium‑sulfur (LiS) batteries become the research hotspot in the field of electrochemical energy storage. However, the serious capacity loss caused by the shuttle effect and the decomposition of polysulfides is the biggest obstacle in the research process and practical application of lithium‑sulfur batteries. Herein, cobalt (Co) and molybdenum carbide (Mo2C) hetero-nanodots wrapping into nitrogen-doped carbon nanotubes (Co-Mo2C@NCNTs) are successfully prepared by direct self-catalysis annealing process. When utilized into the polypropylene (PP) separator modifier, the batteries assembled with Co-Mo2C@NCNTs//PP separator presents high capacity and outstanding rate capability. Specifically, it's worth noting that the cells display a high initial specific capacity of 1463.6mAh g−1 at 0.1C, superior rate capacity of 778.7 mAh g−1 at 3C, and excellent cycle stability with capacity decay rate of only 0.11 % per cycle for 500 cycles at 0.5C. Besides, the outstanding electrochemical performance is also demonstrated under high sulfur loading (3.5 mg cm−2). This work provides a novel guidance direction for high-performance lithium‑sulfur batteries from separator modification.

Slope-structure design towards high-stability P2-Na0.67MnO2 cathode

Layered Mn-based oxide P2-Na0.67MnO2 (NMO) arouses enormous interest for its high specific capacity, easy preparation and low cost. Meanwhile, the P2 → O2 phase transition derived from the slippage of transition metal (TM) layer leads to the inferior performance. Herein, we design a co-doping into Na+ (102 pm) lattice site with smaller-sized Li+ (76 pm) and larger-sized K+ (138 pm) to construct a slope-structured P2-Na0.63K0.02Li0.02MnO2 (NKLMO). The anchored Li+ and K+ can serve as pillar effects and form a geometrically stable resembling triangular structure in the Na-interlayer. Moreover, such a slope-structure is clearly verified by the HRTEM images. In-situ XRD and in-situ EIS tests efficaciously clarify the improved structural stability and even lower impedance during cycling within 2.0–4.2 V, respectively. DFT calculations further confirm the stronger metallicity of NKLMO electrode than the bare NMO originated from the more mobile free electrons surrounding the vicinity of Fermi level. By grace of the more stable slope-structure and faster reaction kinetics, NKLMO is capable of displaying high initial capacity (206.5 mA h/g) and energy density (540 W h kg−1), with a competitive cycling stability at both low and high current rates (96 %@100 cycles@0.1C; 88.4 %@500 cycles@5C). This slope-design is above rubies for tuning chemistry environment to exploit high-stability P2-phase cathodes for sodium-ion batteries.

Lithium-rich manganese-based layered oxide cathode materials for lithium-ion batteries modified by MoS2 coatings with two-dimensional graphene-like structures

Lithium-rich manganese-based layered oxide cathode materials (LRMCs) have some unique advantages such as high theoretical capacity (≥ 250 mAh g−1) and high energy density. Therefore, they are deemed as a kind of cathode material for lithium-ion batteries with an excellent prospect of application. However, the redox of oxygen anion is able to generate irreversible lattice oxygen loss, leading to irreversible loss of capacity, bringing about a sharp drop of working voltage, and seriously restricting the commercialization of LRMCs. In this paper, MoS2 coating with two-dimensional graphene-like structure was coated on the surface of LRMCs materials for improving the cycling stability and rate performance. The MoS2 coating can provide a two-dimensional diffusion channel for the migration of lithium-ions, which facilitates the fast release of lithium-ions during cycling process. The results show that the first discharge capacity, initial Coulomb efficiency and rate performance of LRMCs are improved. When the current density is 1 C, the first discharge specific capacity of LRMCs@MoS2 reaches 227.69 mAh g−1, and the capacity retention ratio is 84.98 % after 100 cycles. When the current density is 5 C, it can still provide a discharge specific capacity of 137.87 mAh g−1, demonstrating excellent electrochemical performance. This study comes up a simple and practical idea to realize the modification of cathode materials for high performance lithium-ion batteries.

A Review of Electrospun Carbon-Based Nanofibers Materials used in Lithium-Sulfur Batteries.

Commercial lithium-ion batteries are gradually approaching their theoretical specific energy, which cannot meet the fast-growing energy storage demands. Lithium-sulfur (Li-S) batteries are anticipated to supersede lithium-ion batteries as the next-generation energy storage system owing to their high atheoretical specific capacity (1675 mAh g-1) and energy density (2600 Wh kg-1). Nonetheless, Li-S batteries encounter several challenges, including the inadequate conductivity of sulfur and lithium sulfide, sulfur's volume expansion, and the shuttle effect of lithium polysulfides, all of which significantly impact the practical utilization of Li-S batteries. Electrospun carbon-based nanofibers can simultaneously resolve these issues with their economical preparation, distinctive nanostructure, and exceptional flexibility. This review presents the most recent research findings on electrospun carbon-based nanofibers materials serving as sulfur hosts and interlayer components in Li-S batteries. We analyzed the impact of the material's structural design on the performance of Li-S batteries and the relative underlying mechanism. Finally, the current challenges and issues faced by carbon-based nanofibers composites in the application of Li-S batteries are summarized, and the future development trajectory are outlined.

The effect of Artemisia capillaris leaf extract as a benign corrosion inhibitor on the performance of Al–air batteries

The self-corrosion of the aluminum anode reduces largely the performance of Al-air batteries. Herein, we report on the effect of Artemisia capillaris leaf extract (ACLE) as a benign corrosion inhibitor on the performance of Al-air batteries in 4 M NaOH electrolyte. The hydrogen evolution tests, electrochemical measurements, and surface analysis show that ACLE can markedly reduce the corrosion current density of the Al electrode in 4 M NaOH, which is due to the adsorption of the active components in ACLE inhibitor on the Al electrode surface. The presence of ACLE in 4 M NaOH greatly reduces the self-corrosion of the Al anode, and thus improves the utilization rate of the Al electrode. Fourier transform infrared (FT-IR) spectroscopy and X-ray photoelectron spectroscopy (XPS) are employed to determine the chemical composition of the adsorption layers on the surface of the Al electrode. When the concentration of ACLE in 4 M NaOH is 5 g/L, the Al-air battery has a high practical capacity density of 3545 Wh kg−1, and the fuel efficiency also increases to a high value of 44 % from 14 % without ACLE. This work presents a novel approach to enhance the performance of Al-air batteries through the utilization of natural product extracts as corrosion inhibitors.

Low temperature resistant flexible zinc-ion hybrid supercapacitor

Zinc-ion hybrid supercapacitors (ZIHS) have high capacity and power density, as well as safety and stability. However, ZIHS are susceptible to electrolyte solidification and deactivation under low temperatures, resulting in rapid capacity degradation. Consequently, their practical use in cold environments is limited. In this study, solid organic hydrogels were prepared as electrolytes using ZnCl2 in a solution of ethylene glycol (EG) and deionized water (H2O), incorporating polyvinyl alcohol (PVA). The hydrogen bonding between PVA and EG effectively suppresses ice crystal formation and promotes the growth of PVA crystal domains. In addition, EG can also form hydrogen bonds with H2O molecules, further preventing H2O crystallization, thereby improving the low temperature resistance of the ZIHS. The results show that the specific capacitance of ZIHS prepared with MnO2 as cathode electrode material and active carbon (AC) as anode electrode material can reach 60 mF cm−2 at −30 °C, and the capacity retention rate can reach 81.2 % after 8000 cycles. In addition, it was found that ZIHS still had good stability after bending at different angles at −30 °C. The development of ZIHS with excellent flexibility and low-temperature resistance is crucial for advancing electronics capable of operating in cold environments.

Energetic Hypervalent Organoiodine Electrochemistry for Aqueous Zinc Batteries.

Hypervalent organoiodine compounds have been extensively utilized in organic synthesis, yet their electrochemical properties remain unexplored despite their theoretically high redox potential compared with inorganic iodine, which primarily relies on the I-/I0 redox couple in battery applications. Here, the fundamental redox mechanism of hypervalent organoiodine in a ZnCl2 aqueous electrolyte is established for the first time using the simplest iodobenzene (PhI) as a model compound. We validated that the PhI to PhICl2 transition is a single-step and reversible reaction, enabling two-electron transfer of I+/I3+ redox chemistry (1.9 V vs Zn2+/Zn) with high capacity (422 mAh giodine-1, and 262.6 mAh g-1 based on PhI) and high theoretical energy density (801.8 Wh kg-1). It was also elucidated that such organoiodine electrochemistry exhibits rich tunability in terms of the global reactivity of various PhI derivatives, including multiple iodine-substituted isomers and functional substituents. Additionally, the stabilizing anion ligands affect the reversibility and stability of trivalent organoiodine compounds. By limiting side reactions and improving the stability of trivalent organoiodine at low temperatures, the zinc-PhI battery demonstrated the feasibility of I+/I3+ conversion and sustained stable performance over 400 cycles. This work bridges the gap between hypervalent organoiodine chemistry and battery technology, highlighting the potential for future high-performance battery applications.

Design and Reaction Mechanism of Rechargeable Lithium-Carbon Fluoride Battery.

Recharging primary batteries is of great importance for increasing the energy density of energy storage systems to power electric aircraft and beyond. Carbon fluoride (CFx) cathodes are characterized by high specific capacity and energy density (865 mAh g-1 and 2180 Wh kg-1, respectively). Preventing the crystallization of LiF with an intermediate and lowering the energy barrier from LiF to CFx is expected to render the Li/CFx battery reversible. In this study, taking the advantage of a high-voltage-stable all-fluorinated electrolyte containing the boron-based anion receptor tris(trimethylsilyl)borate (TMSB), a rechargeable Li/CFx battery was realized with a reversible capacity of 465.9 mAh g-1 and an energy density of 1183.9 Wh kg-1, approximately 53% of that in the first discharge. After the first discharge, the charge-discharge profile featured rechargeable characteristics. In situ X-ray diffraction, ex situ soft X-ray absorption spectroscopy, pair distribution function analysis, and other measurements confirmed the generation and decomposition of Li-F and C-F bonds during cycling. Density functional theory calculations and nuclear magnetic resonance spectroscopy confirmed that TMSB serves as an anion carrier through the generation of a [TMSB-F]- complex, facilitating the conversion reactions during cycling. This study demonstrated a facile and low-cost approach for realizing high-energy-density, reversible Li/CFx batteries.

Alkali-etching Bi-MOF to create oxygen-deficient α-Bi2O3 nanobelt as high-capacity Ni-Bi battery anode

Bi2O3 has been recognized as a promising anode of aqueous secondary battery because of the high capacity, but the application is greatly hindered by the poor conductivity and limited actual capacity. Herein, for the first time, one dimensional (1D) α-Bi2O3 nanobelt is fabricated via alkali etching strategy using rod-shaped Bi-MOF (CAU-17) as the self-sacrificial template. Specifically, high-crystalline and oxygen-deficient α-Bi2O3 nanobelt with length and width of 6 μm and 300 nm are identified. The electrochemical results demonstrate the high specific capacity (247 mAh g−1@1 A g−1) and acceptable stability of α-Bi2O3 nanobelt. Such superior capacity is derived from the exposed electrochemical active sites, fast charge transfer and efficient ion diffusion in 1D high-crystalline and oxygen-vacancies enriched structure. The assembled Ni-Bi battery displays high capacity (78.3 mAh g−1) and high energy density of 100.2 Wh kg−1 (at power density of 2829.8 W kg−1). Our work provides rational guidance for architecting 1D high-capacitive electrodes for aqueous rechargeable alkaline battery.

Synthesis of Nixp/C Nanofibers As Interlayer and Sulfur Host for Lithium-Sulfur Batteries

Lithium-sulfur batteries (LSB) have a high theoretical capacity (1675 mAh g − 1) and energy density (2600 Wh kg−1), making them one of the most promising energy storage systems. 1 However, it has some limitations, such as “shuttle effect” of polysulfides and high volume expansion, causing poor cycle performance of the battery.The transition metal phosphides with carbon materials as sulfur host for LSB have attracted extensive scientific focus due to the large surface area and strong chemisorption ability. Moreover, high electrical conductivity of carbon-based material and the chemical adsorption effect of Ni-P phase can reduce the “shuttle effect”, and improve the cyclability of the material. 2,3 In this work, nickel phosphide carbon composite (NixP/C) nanofibers were synthesized using a water-soluble carbon source polyvinylpyrrolidone (PVP) and cost-effective electrospinning method. The impact of humidity on the physical and electrochemical characteristics of the electrospun NixP/C nanofibers was studied, utilizing them as interlayer and sulfur host material for LSB.The NixP/C nanofibers were synthesized using an electrospinning machine from PVP, nickel nitrate hexahydrate, and phosphoric acid as precursors. The nanofibers were electrospun at 18 kV voltage and 0.8 mL h–1 flow rate. The electrospinning humidity (RH) varied between 19-35%. Obtained nanofibers were dried at 110 ºC for 11 h. Finally, prepared fibers were annealed at 700 ºC for 1 h with a heating rate of 5 ºC min-1 in the N2 + H2 (4%) atmosphere.The crystalline phases of the final products were observed using X-Ray diffraction (XRD, Miniflex, Rigaku). The microstructure was studied by transmission electron microscopy (TEM, JEM-1400 Plus, JEOL). According to the results shown in Figure 1, Ni2P with a hexagonal structure and the space group of P62m, and Ni12P5 with a tetragonal structure, space group of 87:I4/m were formed. Nanoparticles of NixP are uniformly distributed within the carbon fiber matrix (inset).The NixP/C freestanding mats were embedded as a sulfur host or interlayer for LSB in CR2032 coin-type cells. 1 M Li2S6 catholyte solution and 1 M LiTFSI in 1,3- dioxolane (DOL)/1,2 dimethoxyethane (DME) (v/v, 1:1) with 2 wt% of LiNO3 were used as a source of sulfur and electrolyte, respectively. Further details and obtained results will be presented at the conference. Acknowledgements This research was funded by the projects AP13068219 “Development of multifunctional free-standing carbon composite nanofiber mats”, and AP19675260 “Development of nanofibrous electrode materials for next-generation lithium-ion batteries” from the Ministry of Education and Science of the Republic of Kazakhstan.