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With the aid of an ether electrolyte, superior electrochemical performance of free-standing Na3V2(PO4)3 electrodes as the anode, cathode, and full cell is analyzed.

Post-lithium-ion batteries (LIBs) have been widely studied owing to the extensive exploitation of lithium resources. Sodium-ion batteries (SIBs) and potassium-ion batteries (PIBs) are considered su...

Li/S battery has high potential for large scale batteries due to their high theoretical energy density. For high practical energy density of Li/S batteries, a method for synthesizing a new electrode structure should be developed. We demonstrate the development of low-cost Li/S batteries via the simple synthesis of sulfurized polyacrylonitrile (S-PAN) using a glass casting and heating method. The optimum conditions for electrode synthesis were determined using various precursor ratios. Structural characterization of the S-PAN electrodes was performed through scanning electron microscope, X-ray diffractometer, and elemental analysis. At the molecular scale, the S-PAN particles are connected to each other through π-conjugated structures. Furthermore, the electrodes possess high internal porosity, which improves the Li+ ion mobility through enhanced electrolyte uptake. The S-PAN electrodes synthesized using an S:PAN ratio of 5:1 exhibited the best practical capacity after 30 cycles (327 mAh g−1-electrode, 1065 mAh g−1-S). Significantly, the impressive capacity and cyclability of the S-PAN cathode are achieved without using a binder or conducting agents. Therefore, glass-cast S-PAN represents a simple, low-cost approach for synthesizing Li/S batteries with improved capacity.

Transition-metal sulfides have been extensively studied as anode materials for use in sodium-ion batteries (SIBs) and potassium-ion batteries (PIBs) due to their multi-electron reactions, high rate performance, and abundant available resources. However, the practical capacities of metal sulfides remain low due to conductivity issues, volume expansion, and the use of traditional carbonate electrolytes. To overcome these drawbacks, ether electrolytes can be combined with nanoparticle-based metal sulfide anodes. Herein, a nanoparticle-based nickel monosulfide (NiS) anode with high rate performance in the ether electrolytes of SIBs/PIBs was prepared by heating a mixture of nickel nanoparticles with sulfur. In SIBs, the NiS anode capacity was 286 mA h g-1 at a high current density of 100 A g-1, and excellent cycling performance was observed at 25 A g-1 with a capacity of 468 mA h g-1 after 1000 cycles. Moreover, a full-cell containing a Na3V2(PO4) cathode demonstrated a rate performance of 65 mA h g-1 at a high current density of 100 A g-1. In PIBs, the NiS electrode capacity was 642 and 37 mA h g-1 at 0.5 and 100 A g-1, respectively. Hence, the synthesised NiS nanoparticles possessed excellent storage capability, regardless of the alkali-ion type, suggesting their potential use as robust NiS anodes for advanced battery systems.

Owing to the speculated price hike and scarcity of lithium resources, sodium-ion batteries are attracting significant research interest these days. However, sodium-ion battery anodes do not deliver good electrochemical performance, particularly rate performance. Herein, we report the facile electrospinning synthesis of a free-standing nickel disulfide (NiS2) embedded on carbon nanofiber. This electrode did not require a conducting agent, current collector, and binder, and typically delivered high capacity and rate performance. The electrode delivered a high initial capacity of 603 mAh g−1 at the current density of 500 mA g−1. Moreover, the electrode delivered the capacity of 271 mAh g−1 at the high current density of 15 A g−1. The excellent rate performance and high coulombic efficiency of the electrode were attributed to its low charge transfer resistance and unique structure.

Transition metal oxide materials with high theoretical capacities have been studied as substitutes for commercial graphite in lithiumion batteries. Among these, SnO2 is a promising alloying reaction-based anode material. However, the problem of rapid capacity fading in SnO2 due to volume variation during the alloying/dealloying processes must be solved. The lithiation of SnO2 results in the formation of a Li2O matrix. Herein, the volume variation of SnO2 was suppressed by controlling the voltage window to 1 V to prevent the delithiation reaction between Li2O and Sn. Using this strategy the unreacted Li2O matrix was enriched with metallic Sn particles, thereby providing a pathway for lithium ions. The specific capacity decay in the voltage window of 0.05–3 V was 1.8% per cycle. However, the specific capacity decay was improved to 0.04% per cycle after the voltage window was restricted (in the range of 0.05–1 V). This strategy resulted in a specific capacity of 374.7 mAh g−1 at 0.1 C after 40 cycles for the SnO2 anode.

In this work, the hydrothermal method was employed to produce SnO2/rGO as anode material. Nanostructured SnO2 was prepared to enhance reversibility and to deal with the undesirable volume changes during cycling. The SnO2/rGO hybrid exhibits long cycle life in lithium-ion storage capacity and rate capability with an initial discharge capacity of 1327 mAh/g at 0.1 C rate. These results demonstrate that a fabricated SnO2/rGO matrix will be a possible way to obtain high rate performance.

Sulfurized polyacrylonitrile (S-PAN) is one of the best materials for addressing some of the intrinsic drawbacks of lithium–sulfur batteries, such as the intrinsic insulating properties of sulfur and the shuttle phenomenon. Moreover, while S-PAN nanofiber composites are flexible, they still presents shortcomings, such as low rate capability, which is due to their semiconductor electrical conductivity. In this study, we prepared S-PAN webs with high electrical conductivity via electrospinning using conducting agents. Additionally, we analyzed the electrochemical properties of the S-PAN webs prepared using various conducting agents (acetylene black, Ketjen black, and multi-walled carbon nanotubes). The specific capacity of the S-PAN web prepared using acetylene black was 740 mAh g–1 at the charge rate of 5 C. The excellent rate capability of S-PAN prepared using acetylene black was attributed to its low electrical resistance and low charge transfer resistance.

LiNixCoyAlzO2 (NCA) is one of the most promising candidates of cathode material for lithium ion batteries because of its high capacity, energy density, and low cost. However, Ni-rich NCA cathode materials suffer from side reaction (formation of lithium carbonate and hydrogen fluoride attack) between electrolyte and surface of electrode and irreversible phase transition leading to capacity fading and thermal instability. These problems could be improved by coating and doping of transition metal elements. Si doping contributes to stabilization of the unstable R-3m structure, and Ti coating is capable of prohibiting the direct physical contact of electrode with electrolyte. In this work, LiNi0.8Co0.15Al0.05O2 (NCA) cathode materials coated or/and doped by Ti and Si elements were fabricated by co-precipitation method using the ball-milling. The crystal structure, morphology and electrochemical properties are investigated using X-ray diffraction (XRD), scanning electron microscopy (FE-SEM), transmission electron microscopy (FE-TEM), and WBCS3000 (WonA tech Co., Ltd.). The EIS and charge/discharge results of Si doped and Ti coated NCA exhibited the lowest resistance value (147.19 Ω) and capacity retentions of 88% after 100 cycles at 0.5 C.

A highly ordered mesoporous carbon@iron disulfide (CMK-5@FeS2) composite was prepared via an in-situ impregnation and sulfurization method. The CMK-5 matrix with excellent conductivity and high surface area not only formed a continuous conductive network to improve the performance of the CMK-5@FeS2 composite, but also provided sufficient space to buffer the volume changes during cycling. The CMK-5@FeS2 cell exhibited excellent electrochemical performance. After 80 cycles, the CMK-5@FeS2 cell showed the discharge capacities of 650 and 380 mAh g–1 at 2 C and 5 C, respectively. The excellent results show that CMK-5 with unique mesoporous structure can contribute to accelerating ion transfer in the electrode due to the easy accessibility of the electrolyte, which implies CMK-5@FeS2 composite could be a promising cathode active material for rechargeable lithium ion (Li-ion) batteries.

Li[NixCoyMnz]O2 (LiNCM) is one of the candidate cathode material that can replace the currently commercialized LiCoO2 (LCO) cathode material for lithium-ion batteries (LiBs). The morphological feature having primary particle and secondary sphere particle could affect structural stability, tap density and electrochemical performance of LiNCM. In this work, two LiNCM particles without or with the morphological collapse of the secondary particles were prepared by using a co-precipitation-assisted, solid-phase method and ball milling, and its morphological, structural and electrochemical characteristics were evaluated. The results of XRD, and FESEM demonstrated that the as-prepared two LiNCMs have a typical α-NaFeO2 layered structure and the two morphological features of secondary particles needed in this study. The results of electrochemical properties indicated that the LiNCM electrode without collapsed secondary particles have a good stability in cycle performance compared to that with collapse of secondary particles at 0.5, 1.0 and 2 C-rate. The capacity retention of without and with collapsed NCM was 55.8% and 27.3% after 200 cycles at 1 C-rate, respectively.

Recently, sodium ion batteries have attracted considerable interest for large-scale electric energy storage as an alternative to lithium ion batteries. However, the development of anode materials with long cycle life, high rate, and high reversible capacity is necessary for the advancement of sodium ion batteries. Bi anode is a promising candidate for sodium ion batteries due to its high theoretical capacity (385 mAh g–1 or 3800 mAh l–1) and high electrical conductivity (7.7 × 105 S m –1). Herein, we report the preparation of Bi anode using micro-sized commercial Bi particles. DME-based electrolyte was used, which is well known for its high ionic conductivity. The Bi anode showed excellent rate-capability up to 16 C-rate, and long cycle life stability with a high reversible capacity of 354 mAh g–1 at 16 C-rate for 50 cycles.

To improve the electrochemical properties of Ni-rich LiNi0.8Co0.15Al0.05O2 (LiNCA) cathode material, Ti doped or/and Al(OH)3 coated were by co-precipitation-assisted solid-phase and ball milling method was employed in this work. The morphology, structure, and electrochemical performance of the cathode materials were evaluated by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) with energy dispersive X-ray spectrometer (EDS), field emission transmission electron microscopy (FETEM) and electrochemical techniques. Ti doping is introduced into the octahedral lattice space occupied by Li-ions to widen the Li layer spacing and thereby increase the lithium diffusion kinetics. The Al(OH)3 coating also formed a non-uniform layer on the outside of LiNCA, thereby inhibiting side reactions between the electrode and the electrolyte. As a result, the LiNCA electrode showed a high initial discharge capacity of 167.4 mAh/g. However, after 100 cycles, it showed poor cycling stability of 41.7%. In contrast, Ti doped and Al(OH)3 coated LiNCA showed the best cycling stability of 82.2% after 100 cycles.

The purpose of this study is to develop an artificial neural network (ANN) model to predict and analyze the relationship between properties and process parameters of polyvinyl chloride (PVC) composites. The tensile strength, ductility, and density of PVC are modeled as a function of virgin PVC, recycled PVC, CaCO3, di-2-ethylhexyl phthalate, chlorinated paraffin wax, and CaCO3 particle size. The ANN model is trained using the backpropagation algorithm. The developed model was validated with a set of unseen test data. The correlation coefficient adj. R2 values for test data were 0.95, 0.83, and 0.90 for tensile strength, density, and ductility, respectively. The relationship between constituents and properties of PVC composites were analyzed by sensitivity analysis, index of relative importance, and quantitative estimation. The study concluded that ANN modeling was a dependable tool for the optimization of constituents for the desired properties of PVCs.

Sodium-ion batteries (SIBs) are a viable substitute for lithium-ion batteries due to the low cost and wide availability of sodium. However, practical applications require the development of fast charging sodium-ion-based full-cells with high power densities. Na3V2(PO4)3 (NVP) is a bipolar material with excellent characteristics as both a cathode and an anode material in SIBs. Designing symmetric cells with NVP results in a single voltage plateau with significant specific capacity which is ideal for a full cell. Here we demonstrate for the first time a tremendous improvement in the performance of NVP symmetric full cells by introducing an ether-based electrolyte which favors fast reaction kinetics. In a symmetric full cell configuration, 75.5% of the initial capacity was retained even after 4000 cycles at 2 A g−1, revealing ultra-long cyclability. Excellent rate performances were obtained at current densities as high as 1000C, based on the cathode mass, revealing ultrafast Na+ transfer. The power density obtained for this NVP symmetric cell (48 250 W kg−1) is the best among those of all the sodium-ion-based full cells reported to date.

Sodium vanadium phosphate (NVP) is a potential cathode material for sodium-ion batteries, but its rate capability requires improvement. Herein, the electrode–electrolyte interface is modified using dimethyl ether (DME) electrolyte, such that the porous NVP cathode leads to ultrafast kinetics and ultra-long cycle life in comparison to those observed using conventional ethylene carbonate/propylene carbonate electrolytes. The rate capability and cycle life are the highest reported to date. The Na/NVP half-cell with DME affords good capacity (44 mA h g−1 at 100 A g−1; 854C) and stable ultra-long cycle life for 95 000 cycles with a negligible degradation rate (5.8 × 10−5 % per cycle at 50 A g−1, i.e., 1.05 Na+ reversibly reacts with NVP within 4.5 s). The NVP full cell coupled with a Sn anode delivers a reversible capacity of 70 mA h g−1 at 10 A g−1 for 5000 cycles with 100% coulombic efficiency. After 5000 cycles, the energy density is 217 W h kg−1 and the power density is 30 985 W kg−1 (based on NVP mass). The DME electrolyte effectively modifies the interface for fast kinetics both as a half-cell and a full cell. This simple strategy can be extended to other battery systems to achieve fast kinetics.

Removing decolorizing acid blue 113 (AB113) dye from textile wastewater is challenging due to its high stability and resistance to removal. In this study, we used an artificial neural network (ANN) model to estimate the effect of five different variables on AB113 dye removal in the sonophotocatalytic process. The five variables considered were reaction time (5–25 min), pH (3–11), ZnO dosage (0.2–1.0 g/L), ultrasonic power (100–300 W/L), and persulphate dosage (0.2–3 mmol/L). The most effective model had a 5-7-1 architecture, with an average deviation of 0.44 and R2 of 0.99. A sensitivity analysis was used to analyze the impact of different process variables on removal efficiency and to identify the most effective variable settings for maximum dye removal. Then, an imaginary sonophotocatalytic system was created to measure the quantitative impact of other process parameters on AB113 dye removal. The optimum process parameters for maximum AB 113 removal were identified as 6.2 pH, 25 min reaction time, 300 W/L ultrasonic power, 1.0 g/L ZnO dosage, and 2.54 mmol/L persulfate dosage. The model created was able to identify trends in dye removal and can contribute to future experiments.

In order to satisfy the escalating energy demands, it is inevitable to improve the energy density of current Li-ion batteries. As the development of high-capacity cathode materials is of paramount significance compared to anode materials, here we have designed for the first time a unique synergistic hybrid cathode material with enhanced specific capacity, incorporating cost-effective iron sulfide (FeS) nanoparticles in a sulfurized polyacrylonitrile (SPAN) nanofiber matrix through a rational in situ synthesis strategy. Previous reports on FeS cathodes are scarce and consist of an amorphous carbon matrix to accommodate the volume changes encountered during the cycling process. However, this inactive buffering matrix eventually increases the weight of the cell, reducing the overall energy density. By the rational design of this hybrid composite cathode, we ensure that the presence of covalently bonded sulfur in SPAN guarantees high sulfur utilization, while effectively buffering the volume changes in FeS. Meanwhile, FeS can compensate for the conductivity issues in the SPAN, thereby realizing a synergistically driven dual-active cathode material improving the overall energy density of the composite. Simultaneous in situ generation of FeS nanoparticles within the SPAN fiber matrix was carried out via electrospinning followed by a one-step heating procedure. The developed hybrid cathode material displays enhanced lithium-ion storage, retaining 688.6 mA h g

Sn/SnO2 nanocomposite of core-shell structure covered with multilayer graphene was synthesized by one step process of electrical wire explosion in liquid media. The synthesized Sn/SnO2 nanocomposites were characterized by various analyzers such as Raman, XRD, FESEM, FETEM, XPS and TGA. The electrochemical performance of the electrode has been investigated by galvanostatic cycling and cyclic voltammetry. FESEM and FETEM results showed that diameter of the Sn/SnO2 nanoparticles is around 10–50 nm and the thickness of the SnO2 shell is about 5–8 nm. The nanocomposite electrode showed a high specific capacity of 1270 mAhg−1 after 100 cycles. Furthermore, the nanocomposite exhibited high reversible capacity of around 650 mAhg−1 at the current density of 5000 mAg−1. These results indicated that multilayer graphene-encapsulated Sn/SnO2 nanocomposites are one of rational structural design to improve the electrochemical performance of Sn-based anode materials for LIBs.

Silicon, owing to its exceptionally high theoretical capacity of 4200 mAh/g, is one of the potential anode materials explored by the lithium ion battery community. However, it undergoes tremendous volume expansion upon cycling that result in the material fracture and cracking, leading to electronic isolation and loss of cycle-able Li. In the present study, Si-nanopowder inserted Cu plates are utilized as current collectors so as to accommodate the volume expansion and electronic isolation caused by the secession of active materials from the electrode upon electrochemical cycling. The Cu plates are etched with sandpapers of different grades to effectively enable the Si insertion by a simple and facile brushing method. Electrodes were finally coated with a binder layer for encapsulation of Si active materials and were compared in terms of the electrochemical performances. The electrochemical investigations reveal that the electrodes fabricated by the surface modified Si/Cu plates with the SiC sandpaper #800 coupled with the binder coating afforded the best electrochemical performance among the electrodes investigated with excellent capacity retention of 1074 mAh/g even after 1000 cycles.

A freestanding porous sulfurized polyacrylonitrile/vapor grown carbon fiber (SVF) composite was prepared as cathode material for high-performance lithium sulfur batteries by a facile electrospinning technique. The synthesized composite possessed high sulfur utilization, high Coulombic efficiency, and excellent cycling stability with the property of flexibility, essential to the development of flexible batteries. The capacity retentions of the SVF cell were 903 mAh g−1 after 150 cycles at 1 C and 600 mAh g−1 after 300 cycles at 2 C. At a high rate of 4 C, the SVF composite showed reasonable capacity retention. The superior performance of SVF composite was attributed to the highly porous structure, which effectively improved the wettability, accessibility, and absorption of electrolyte to facilitate rapid ion transfer in the cell. Vapor-grown carbon fibers embedded inside SVF as a carbon material notably enhanced the electrical conductivity of the cell, guaranteeing the electrochemical performance at high C-rates. The freestanding porous SVF fiber composite is a promising cathode material for advanced flexible lithium sulfur batteries.

Iron sulfide (FeS) has gained reasonable attention as a potential electrode material for lithium-ion batteries owing to its high specific capacity. However, along with the intrinsically low conductivity of FeS, the generation of polysulfide intermediates and volume expansion encountered during the cycling process deteriorates its electrochemical performance. A viable solution would be to design conductive carbon nanoarchitectures capable of effectively accommodating electrochemically active FeS to provide an appropriate conductive pathway which can accelerate ion/electron transport. With this objective, we report a facile, green strategy that facilitates the in situ generation of FeS nanoparticles within graphitic carbon capsules (FeS@GCC) derived from waste biomass. Unlike the complex synthetic procedures reported before, the proposed ecofriendly strategy consists of simpler and fewer processing steps, thereby advocating the versatility of this method as a scalable and economic approach. The FeS@GCC comp...

During the development of sodium ion batteries (SIBs), a long cycle life, high capacity, and high rate are required for the anode materials. In this study, CuS is synthesized by heating S on a Cu current collector at 80 °C for 5 h, which is a simple and scalable process. The CuS exhibits excellent cycle stability of 517 mA h g−1 at 5 A g−1 after 2000 cycles, with 99.2% retention and a coulombic efficiency of almost 100%. CuS also exhibits an ultrahigh rate capability up to 100 A g−1 with a 268 mA h g−1. The CuS electrode is suitable for mass production and displays excellent electrochemical performance; therefore, it is a promising anode for SIBs. Moreover, ex situ scanning electron microscopes are applied to investigate their structural changes. During cycling, the shape of the electrode changes to multiundulating, and then to a flat plate covered with nanometer-sized particles, which can be induced by cracking, pulverization, and agglomeration. Through agglomeration, the CuS recovers from the electric isolation caused by pulverization. This self-healing characteristic could represent a new way of obtaining a long cycle life for anodes with volume changes.

Since flexible devices are being used in various states of charge (SoCs), it is important to investigate SoCs that are durable against external mechanical deformations. In this study, the effects of a mechanical fatigue test under various initial SoCs of batteries were investigated. More specifically, ultrathin pouch-type Li-ion polymer batteries with different initial SoCs were subjected to repeated torsional stress and then galvanostatically cycled 200 times. The cycle performance of the cells after the mechanical test was compared to investigate the effect of the initial SoCs. Electrochemical impedance spectroscopy was employed to analyze the interfacial resistance changes of the anode and cathode in the cycled cells. When the initial SoC was at 70% before mechanical deformation, both electrodes well maintained their initial state during the mechanical fatigue test and the cell capacity was well retained during the cycling test. This indicates that the cells could well endure mechanical fatigue stress when both electrodes had moderate lithiation states. With initial SoCs at 0% and 100%, the batteries subjected to the mechanical test exhibited relatively drastic capacity fading. This indicates that the cells are vulnerable to mechanical fatigue stress when both electrodes have high lithiation states. Furthermore, it is noted that the stress accumulated inside the batteries caused by mechanical fatigue can act as an accelerated degradation factor during cycling.

Sulfurized polyacrylonitrile (SPAN) is a promising active material for Li/S batteries owing to its high sulfur utilization and long-term cyclability. However, because SPAN electrodes are synthesized using powder, they require large amounts of electrolyte, conducting agents, and binder, which reduces the practical energy density. Herein, to improve the practical energy density, we fabricated bulk-type SPAN disk cathodes from pressed sulfur and polyacrylonitrile powders using a simple heating process. The SPAN disks could be used directly as cathode materials because their π–π structures provide molecular-level electrical connectivity. In addition, the electrodes had interconnected pores, which improved the mobility of Li+ ions by allowing homogeneous adsorption of the electrolyte. The specific capacity of the optimal electrode was very high (517 mA h gelectrode−1). Furthermore, considering the weights of the anode, separator, cathode, and electrolyte, the Li/S cell exhibited a high practical energy density of 250 W h kg−1. The areal capacity was also high (8.5 mA h cm−2) owing to the high SPAN loading of 16.37 mg cm−2. After the introduction of 10 wt% multi-walled carbon nanotubes as a conducting agent, the SPAN disk electrode exhibited excellent cyclability while maintaining a high energy density. This strategy offers a potential candidate for Li/S batteries with high practical energy densities.

The efficiency of heavy metal in biofilm reactors depends on absorption process parameters, and those relationships are complicated. This study explores artificial neural networks (ANNs) feasibility to correlate the biofilm reactor process parameters with absorption efficiency. The heavy metal removal and turbidity were modeled as a function of five process parameters, namely pH, temperature(°C), feed flux(ml/min), substrate flow(ml/min), and hydraulic retention time(h). We developed a standalone ANN software for predicting and analyzing the absorption process in handling industrial wastewater. The model was tested extensively to confirm that the predictions are reasonable in the context of the absorption kinetics principles. The model predictions showed that the temperature and pH values are the most influential parameters affecting absorption efficiency and turbidity.

Celestite and barite formation results in contamination of barium and strontium ions hinder oilfield water purification. Conversion of bio-waste sorbent products deals with a viable, sustainable and clean remediation approach for removing contaminants. Biochar sorbent produced from rice straw was used to remove barium and strontium ions of saline water from petroleum industries. The removal efficiency depends on biochar amount, pH, contact time, temperature, and Ba/Sr concentration ratio. The interactions and effects of these parameters with removal efficiency are multifaceted and nonlinear. We used an artificial neural network (ANN) model to explore the correlation between process variables and sorption responses. The ANN model is more accurate than that of existing kinetic and isotherm equations in assessing barium and strontium removal with adj. R2 values of 0.994 and 0.991, respectively. We developed a standalone user interface to estimate the barium and strontium removal as a function of sorption process parameters. Sensitivity analysis and quantitative estimation were carried out to study individual process variables' impact on removal efficiency.

Usage of cyclic volatile methyl siloxanes (cVMSs) in the industrial process is unavoidable due to their superior properties; however, it is hazardous to human health. Photocatalytic zinc oxide coated aluminum anode is used to degrade the cVMSs in wastewater. In this work, we investigated the relationship among degradation process parameters such as current density (4–20 mA/cm2), initial pH (5–9), plate distance (8–24 cm), UV intensity (0–120 W), and reaction time (30–100 min) vis-a-vis cVMSs removal efficiency by using data-driven artificial neural networks(ANN) model. The ANN model was trained using a backpropagation algorithm with the sigmoid activation function between input, hidden, and the output layers. Two hidden layers with eight neurons in each layer presented the minimum average training error (0.24) and higher (0.99) correlation coefficient values (both Pearson’s r and Adj. R2) as compared with the conventional regression model. The effect and relationship between the parameters and cVMSs removal efficiency were analyzed by single, two variable sensitivity analysis, qualitative and quantitative estimation.

Sodium-ion batteries (SIBs) are a viable substitute for lithium-ion batteries due to the low cost and wide availability of sodium. However, practical applications require the development of fast charging sodium-ion-based full-cells with high power densities. Na

To develop the next-generation energy storage systems, lithium-sulfur batteries represent an attractive option due to its high theoretical capacity, and energy density. In this work, MoS₂/rGO (reduced graphene oxide) was prepared by hydrothermal synthesis and sulfur added by the melt diffusion method. The as-prepared MoS₂/rGO has strong polysulfides entrapping, high conductivity, large surface area, and high catalytic activity, consequently resulting in enhanced rate performance and cycling capability of Li-S batteries. The coin cells were constructed with the MoS₂/rGO/S cathode material, exhibit a high reversible capacity of nearly 1380 mAh/g at 0.1 C, outstanding cycling stability with a low capacity fading rate. Present work reveals that the hierarchal MoS₂/rGO/S cathodes are potential candidate materials for future high-performance lithium-sulfur batteries.

In this paper, the relationship between the pore spatial structures, pore sizes, and pore types of highly ordered mesoporous CMK-based carbons (CMK-1, CMK-3, and CMK-5) and their electrochemical performance in Li-S batteries is investigated. CMK-1 has a complex spatial structure and small pores. The structure is good for limiting polysulfide in the pores, but not for rapid transfer of Li+ ions in the cell. CMK-3 and CMK-5 have similar spatial structures and pore sizes, but different pore types. Compared to the single pore structure of CMK-3, the bimodal pore structure of CMK-5 not only improves the electrolyte accessibility, but also increases the number of reaction sites, resulting in better electrochemical performance. Studying the correlation between the physical structure of carbon-based materials and their electrochemical performance in Li-S batteries will provide new insights for optimizing porous electrode materials.

Owing to the speculated price hike and scarcity of lithium resources, sodium-ion batteries are attracting significant research interest these days. However, sodium-ion battery anodes do not deliver good electrochemical performance, particularly rate performance. Herein, we report the facile electrospinning synthesis of a free-standing nickel disulfide (NiS²) embedded on carbon nanofiber. This electrode did not require a conducting agent, current collector, and binder, and typically delivered high capacity and rate performance. The electrode delivered a high initial capacity of 603 mAh g

In this study, NiS/graphene nanocomposites were synthesized by simple heat treatment method of three graphene materials (graphene oxide (GO), reduced graphene oxide (rGO) and nitrogen-doped graphene oxide (N-rGO)) and NiS precursor. The morphology and crystal structure of NiS/graphene nanocomposites were characterized using field emission scanning electron microscope (FE-SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. Electrochemical properties were also investigated. NiS/graphene nanocomposites homogeneously wrapped by graphene materials have been successfully manufactured. Among the three nanocomposites, NiS/N-rGO nanocomposite exhibited the highest initial and retention capacity in discharge, respectively, of 1240 mAh/g and 467 mAh/g up to 100 cycles at 0.5 C.