Fast Charge-discharge Performance Research Articles

(NH4)2V4O9 nanosheets coexisting with carbon nanotubes for high performance in aqueous zinc ion batteries

In this paper, (NH4)2V4O9 nanosheets coexisting with carbon nanotubes were prepared by hydrothermal method as cathode materials for aqueous zinc ions, which can improve the electrochemical performance of the battery. The structure, morphology and electrochemical properties of (NH4)2V4O9/CNTs were studied and analyzed by physical characterization and electrochemical tests. Carbon nanotubes coexisting with (NH4)2V4O9 provide an electron transfer channel, significantly improving the rate performance of the material. The discharge specific capacity of (NH4)2V4O9/CNTs is 445 mAh g−1 at a current of 0.1 A g−1; while the discharge specific capacity still remains 207.16 mAh g−1 when the current up to 5.0 A g−1. After 2000 cycles at a high current density of 10 A g−1, the discharge specific capacity of the battery remained 93.1 mAh g−1 from 115.2 mAh g−1 in the first cycle, showing good cycle performance. Therefore, (NH4)2V4O9/CNTs has fast charge-discharge performance and cycle stability.

Two-dimensional LiTi2(PO4)3 flakes for enhanced lithium ions battery anode

In this work, the LiTi2(PO4)3 (LTP) flakes have been prepared by employing a template method for lithium-ion batteries with high capacity. The 2D layered structure of LTP offers large aspect ratio and rich active sites, which not only create the large contact area between the electrolyte and electrode, but also promote the diffusion kinetics of Li+. As a result, the Li+ diffusion coefficient of lamellar LTP anode is 3.12 × 10−8 cm2 s−1, while it is only 5.01 × 10−10 cm2 s−1 for granular LTP anode. Further, the lamellar LTP anode delivers a high initial discharge capacity of 986.8 mAh·g−1 at 0.1 A g−1, and remains at 231.1 mAh·g−1 after 100 cycles, which is higher than that of the granular LTP anode (340.5 mAh·g−1 at 1st cycle, 169.3 mAh·g−1 at 100th cycles). Thus, the lamellar LTP should be recommended as a potential anode for high-performance LIBs due to the fast charge-discharge performance and superior cycling stability.

MnO2-graphene based composites for supercapacitors: Synthesis, performance and prospects

Supercapacitors stand out among some traditional energy storage devices due to their advantages such as long cycle stability, fast charge-discharge performance and high-power density. Therefore, it is necessary to explore high-performance electrode materials for application in supercapacitors. Manganese dioxide (MnO 2 ) has high theoretical capacitance and high energy density, however, the deterioration of volume expansion and low conductivity directly affect its wide application. Graphene has attracted great interest owing to its invention. The combination of graphene and MnO 2 can not only highlight the low resistance, large specific surface area and thermal stability of graphene, but also solve the shortcomings of MnO 2 alone as an electrode material. The proposal of composite materials has also promoted the development and application of electrode materials in supercapacitors. Hence, this review aims to summarize the synthetic strategies and research progress of MnO 2 -graphene based multi-element composites, including the combination of MnO 2 -graphene with various carbon materials, transition metal oxides and conducting polymers, respectively. Finally, the possible development directions of MnO 2 -graphene based composite electrode materials in the future are also prospected. • Focusing on the synthesis strategy and electrochemical performance. • Multi-composites exert synergistic effects and offer significant performance. • MnO 2 -graphene based composites still have a promising future in other fields.

Effects of the Separator MOF-Al2O3 Coating on Battery Rate Performance and Solid-Electrolyte Interphase Formation.

Metal organic frameworks (MOFs) have unique advantages in optimizing the ionic conductivity of battery separators because of their rich cavity structure and highly ordered and connected pores. In this study, we used a hydrothermal method to synthesize a functional material, Ag-MOF crystal, as a separator coating content, and then studied the properties and application effect of the MOF-Al2O3-blended coating applying to a polyethylene (PE) separator (MOFxAl1-x/PE). Results show that MOF0.08Al0.92/PE (MOF/Al2O3 = 0.08:0.92) used in NCM811||Li cells significantly not only improves the fast charge-discharge performance of the cells but also inhibits the growth of lithium dendrites during long-term charge-discharge cycling; the Li+ transference number (tLi+) of the MOF0.08Al0.92/PE composite separator is 0.61; the Li||separator||Li half-cell circulates stably for 1000 h at varying current density from 0.5 to 10 mA cm-2 and only produces low overpotentials, indicating that MOF0.08Al0.92 stabilizes lithium. The initial capacity of the NCM811||Li cell using the MOF0.08Al0.92/PE separator is 165.0 mA h g-1, its capacity retention is 70.67% after 300 cycles at 5 C, and the interface resistance of the cells only increases from 13.8 to 31.5 Ω, whereas the capacity retention of Al2O3/PE separator batteries is only 40.41% (62.2 mA h g-1) under the same conditions. During the charge-discharge cycling, the MOF-Al2O3 coating induces the lithium anode to quickly form a stable and dense solid-electrolyte interphase layer, promotes the uniform deposition of Li+, and inhibits the growth of lithium dendrites as well.

Hollow-structured Cu0.4Zn0.6Fe2O4 as a novel negative electrode material for high-performance lithium-ion batteries

Novel hollow-structured Cu0.4Zn0.6Fe2O4 porous negative electrode material is synthesized using a one-step spray pyrolysis method, which exhibits excellent rate capability, high cycling stability, and fast charge-discharge performance in Li-ion batteries. Evaluation of lithium storage properties reveals that the hollow Cu0.4Zn0.6Fe2O4 nanospheres exhibit high specific capacity of 1122 mAh g−1 at a current density of 100 mA g−1, excellent rate capabilities up to 1500 mA g−1 and long term cycling stabilities at a high rate of 1000 mA g−1. Interestingly, the hollow cavity and porous textures of the Cu0.4Zn0.6Fe2O4 anode are well retained even after 1000 cycles at 1000 mA g−1. The synergistic effect among the different cations, as well as the nano-dimension coupled with a hollow interior and surface porosity of the electrode materials, not only facilitate Li-ion and electron transportation kinetics but also accommodate large volume expansion.

High-capacity and cycling-stable polypyrrole-coated MWCNT@polyimide core-shell nanowire anode for aqueous rechargeable sodium-ion battery

Aqueous rechargeable sodium-ion batteries (ARSBs) have potential applications in large-scale electric energy storage systems because of the non-flammable and fast charge-discharge performance of the aqueous neutral electrolyte as well as low cost and abundance of sodium resources. Herein, we demonstrate polypyrrole-coated MWCNT@polyimide core-shell nanowire based on pyromellitic dianhydride (PMDA) and 4,4′-oxydianiline (ODA) as a high-capacity and cycling-stable anode material for ARSBs. The as-synthesized MWCNT@polyimide core-shell nanowire exhibits excellent initial discharge capacity as high as 234.9 mA h g −1 , which is 83.6% of the theoretical value, owing to the bicontinuous electron/ion transport pathway. During 100 cycles of charge-discharge, however, the considerable swelling of PMDA-ODA polyimide and structural degradation of core-shell structure result in significant deterioration in the performance from 234.9 to 74.6 mAh g −1 . In order to improve the cycling stability, conducting polypyrrole is coated on its surface. After 100 charge-discharge cycles, the polypyrrole-coated MWCNT@polyimide core-shell nanowire retains a specific capacity of 209.3 mA h g −1 , corresponding to 77.8% of the initial capacity, without any swelling and structural degradation. In impedance study, the changes in the surface and charge transfer resistances during charge-discharge cycles are significantly reduced. As a result, the polypyrrole layer successfully inhibits the structural degradation of the MWCNT@polyimide core-shell nanowire, and consequently improves the cycling performance. • MWCNT@polyimide nanowire is used as an anode for aqueous sodium-ion battery. • Commercially available PMDA-ODA polyimide is used as active material. • The specific capacity is 209.3 mA h g −1 after 100 cycles at 280 mA g −1 (1C). • Polypyrrole layer on polyimide inhibits the degradation of PMDA-ODA polyimide.

Supramolecular Self-Assembly of 3D Conductive Cellulose Nanofiber Aerogels for Flexible Supercapacitors and Ultrasensitive Sensors.

Nature employs supramolecular self-assembly to organize many molecularly complex structures. Based on this, we now report for the first time the supramolecular self-assembly of 3D lightweight nanocellulose aerogels using carboxylated ginger cellulose nanofibers and polyaniline (PANI) in a green aqueous medium. A possible supramolecular self-assembly of the 3D conductive supramolecular aerogel (SA) was provided, which also possessed mechanical flexibility, shape recovery capabilities, and a porous networked microstructure to support the conductive PANI chains. The lightweight conductive SA with hierarchically porous 3D structures (porosity of 96.90%) exhibited a high conductivity of 0.372 mS/cm and a larger area-normalized capacitance (Cs) of 59.26 mF/cm2, which is 20 times higher than other 3D chemically cross-linked nanocellulose aerogels, fast charge-discharge performance, and excellent capacitance retention. Combining the flexible SA solid electrolyte with low-cost nonwoven polypropylene and PVA/H2SO4 yielded a high normalized capacitance (Cm) of 291.01 F/g without the use of adhesive that was typically required for flexible energy storage devices. Furthermore, the supramolecular conductive aerogel could be used as a universal sensitive sensor for toxic gas, field sobriety tests, and health monitoring devices by utilizing the electrode material in lightweight supercapacitor and wearable flexible devices.

Co3O4@NiCo2O4 microsphere as electrode materials for high-performance supercapacitors

In this work, hierarchical Co3O4@NiCo2O4 microspheres composed of nano particles grown on nickel foam as supercapacitor electrode material were designed by a hydrothermal route, following an ultrasonic-assisted process. The introduction of moderate amounts NiCo2O4 in Co3O4 can decrease charge transfer resistance and enhance the transfer of electrons and ions. Therefore, Co3O4@NiCo2O4 (4:1) shows an excellent specific capacitance of 879.4 F g−1 at 10 A g−1, and the capacitance retention maintains 81.2% of its first capacitance after 3000 cycles, indicating a high cycling durability and outstanding fast charge-discharge performance. The outstanding property exhibits that the hierarchical Co3O4@NiCo2O4 (4:1) microsphere has tremendous application potential in supercapacitors.

Li5Cr7Ti6O25/Multiwalled Carbon Nanotubes Composites with Fast Charge-Discharge Performance as Negative Electrode Materials for Lithium-Ion Batteries

In this study, Li5Cr7Ti6O25/ multiwalled carbon nanotubes (LCTO@MWCNTs) negative electrode materials were prepared via a sol-gel method. The physical and electrochemical properties of LCTO@MWCNTs (0, 3, 5 and 8 wt%) were systematically investigated. The results show that LCTO@MWCNTs (5 wt%) shows the best electrochemical properties in all samples. Cycled at 6 C, the LCTO@MWCNTs (5 wt%) composite delivers a charge capacity of 129.9 mA h g−1, and the reversible capacity also achieves 123.8 mAh g−1 after 400 cycles in the voltage range of 1.0-3.0V. Nevertheless, the pure LCTO only delivers a capacity of 91.2 mA h g−1 and the capacity only reaches 84.9 mA h g−1 after 400 cycles. The further study results indicate that the prepared LCTO@MWCNTs composites have higher electronic conductivity and lithium diffusion coefficient than the pure LCTO.

Novel Sodium Niobate-Based Lead-Free Ceramics as New Environment-Friendly Energy Storage Materials with High Energy Density, High Power Density, and Excellent Stability

Recently, ceramic capacitors with fast charge–discharge performance and excellent energy storage characteristics have received considerable attention. Novel NaNbO3-based lead-free ceramics (0.80NaN...

One-Dimensional Porous Silicon Nanowires with Large Surface Area for Fast Charge⁻Discharge Lithium-Ion Batteries.

In this study, one-dimensional porous silicon nanowire (1D–PSiNW) arrays were fabricated by one-step metal-assisted chemical etching (MACE) to etch phosphorus-doped silicon wafers. The as-prepared mesoporous 1D–PSiNW arrays here had especially high specific surface areas of 323.47 m2·g−1 and were applied as anodes to achieve fast charge–discharge performance for lithium ion batteries (LIBs). The 1D–PSiNWs anodes with feature size of ~7 nm exhibited reversible specific capacity of 2061.1 mAh·g−1 after 1000 cycles at a high current density of 1.5 A·g−1. Moreover, under the ultrafast charge–discharge current rate of 16.0 A·g−1, the 1D–PSiNWs anodes still maintained 586.7 mAh·g−1 capacity even after 5000 cycles. This nanoporous 1D–PSiNW with high surface area is a potential anode candidate for the ultrafast charge–discharge in LIBs with high specific capacity and superior cycling performance.

Porous sphere-like LiNi0.5Mn1.5O4-CeO2 composite with high cycling stability as cathode material for lithium-ion battery

A new type of microsized porous spherical LiNi0.5Mn1.5O4-CeO2 cathode material composed of aggregated nanosized particles with P4332 space groups was prepared by an ethanol-assisted hydrothermal method. The nanosized particle shortens the Li+-ion diffusion path in the bulk LiNi0.5Mn1.5O4 and then improves the fast charge–discharge performance of this material. Moreover, a thin CeO2 layer with nanometer thickness on the surface of the LiNi0.5Mn1.5O4 particles is helpful for suppressing the interfacial side reactions. Because of these advantages, the LiNi0.5Mn1.5O4-CeO2 materials exhibit excellent electrochemical properties. Compared with the pristine LiNi0.5Mn1.5O4, LiNi0.5Mn1.5O4-CeO2 (3 wt%) exhibits outstanding discharge capacity, cycling stability and rate capability. LiNi0.5Mn1.5O4-CeO2 (3 wt%) delivers discharge capacities of 129.7, 121.2, 118.1, 109.8, and 86.3 mAh g−1 at 0.2, 0.5, 1, 2, and 5 C discharge rates, but the pristine one only delivers discharge capacities of 119.9, 103.7, 91.8, 84.7 and 34.4 mAh g−1 at the corresponding discharge rates. The introduction of CeO2 is a valid approach to enhance the electrochemical property of the LiNi0.5Mn1.5O4 material by forming an excellent electrical contact between CeO2 layer and LiNi0.5Mn1.5O4 surface, leading to an enhanced lithium-ion diffusion coefficient, reduced electrochemical polarization, and improved conductivity.

Improved Cycling Stability and Fast Charge-Discharge Performance of Cobalt-Free Lithium-Rich Oxides by Magnesium-Doping.

Layered Li-rich, Co-free, and Mn-based cathode material, Li1.17Ni0.25-xMn0.58MgxO2 (0 ≤ x ≤ 0.05), was successfully synthesized by a coprecipitation method. All prepared samples have typical Li-rich layered structure, and Mg has been doped in the Li1.17Ni0.25Mn0.58O2 material successfully and homogeneously. The morphology and the grain size of all material are not changed by Mg doping. All materials have a estimated size of about 200 nm with a narrow particle size distribution. The electrochemical property results show that Li1.17Ni0.25-xMn0.58MgxO2 (x = 0.01 and 0.02) electrodes exhibit higher rate capability than that of the pristine one. Li1.17Ni0.25-xMn0.58MgxO2 (x = 0.02) indicates the largest reversible capacity of 148.3 mAh g-1 and best cycling stability (capacity retention of 95.1%) after 100 cycles at 2C charge-discharge rate. Li1.17Ni0.25-xMn0.58MgxO2 (x = 0.02) also shows the largest discharge capacity of 149.2 mAh g-1 discharged at 1C rate at elevated temperature (55 °C) after 50 cycles. The improved electrochemical performances may be attributed to the decreased polarization, reduced charge transfer resistance, enhanced the reversibility of Li+ ion insertion/extraction, and increased lithium ion diffusion coefficient. This promising result gives a new understanding for designing the structure and improving the electrochemical performance of Li-rich cathode materials for the next-generation lithium-ion battery with high rate cycling performance.

Enhanced electrochemical performance of Li-rich low-Co Li1.2Mn0.56Ni0.16Co0.08−x Al x O2 (0≤x≤0.08) as cathode materials

Layered Li1.2Mn0.56Ni0.16Co0.08− x Al x O2 (0 ≤ x ≤ 0.08) cathode materials were successfully synthesized by a sol-gel method. X-ray diffraction and the refinement data indicate that all materials have typical α-NaFeO2 structure with R -3 m space group, and the a -axis has almost no change, but there is a slight decrease in the c lattice parameter as well as the cell volume. Scanning electron microscopy and high resolution transmission electron microscopy prove that all the samples have uniform particle size of about 200–300 nm and smooth surface. The energy-dispersive X-ray spectroscopy mapping shows that aluminum has been homogeneously doped in the Li1.2Mn0.56Ni0.16Co0.08O2 cathode material. The cyclic voltammetry and electrochemical impedance spectroscopy reveal that appropriate Al-doping contributes to the reversible lithium-ion insertion and extraction, and then reduces the electrochemical polarization and charge transfer resistance. Li1.2Mn0.56Ni0.16Co0.08− x Al x O2 ( x = 0.05) shows the lowest charge transfer resistance and the highest lithium-ion diffusion coefficient among all the samples. The Li-rich electrodes with low-level Al doping shows a much higher discharge capacity than the pristine one, especially the Li1.2Mn0.56Ni0.16Co0.08− x Al x O2 ( x = 0.05) sample, which exhibits greater rate capacity and better fast charge-discharge performance than the other samples. Li1.2Mn0.56Ni0.16Co0.08− x Al x O2 ( x = 0.05) also exhibits higher discharge capacity than the pristine one at each cycle at 55°C. These results clearly indicate that the high rate capacity together with a good high rate cycling performance and high-temperature performance of the low-Co Li1.2Mn0.56Ni0.16Co0.08− x Al x O2 ( x =0.05) is a promising alternative to next-generation lithium-ion batteries.

High rate cycling performance of nanosized Li4Ti5O12/graphene composites for lithium ion batteries

Nanosized Li4Ti5O12/graphene(LTO/graphene) materials have been successfully synthesized by a sol-gel method. The LTO/graphene composites exhibit a well-defined cubic spinel structure with an average particle size of approximately 200–500nm. Compared with pure Li4Ti5O12, LTO/graphene composites show higher specific capacity, much improved rate capability and better cycle stability when used as anode materials for lithium ion batteries. The initial capacity of the LTO/graphene composite(0.5wt%) reaches 170.7mAhg−1at 1C, which slightly decreases to 168.5mAhg−1 after 100 cycles with a capacity loss of 1.3%. More importantly, the resulting LTO/graphene (0.5wt%) sample demonstrates remarkable rate capability in that it delivers a reversible capacity of 108.4mAhg−1 in the 1000th cycle at 10C charge-discharge rate, about 2.5 times that of pristine Li4Ti5O12 particles (44.1mAhg−1). The improved high-rate capability, cycling stability, fast charge-discharge performance of LTO/graphene composites can be ascribed to the improvement of lithium ion diffusion and ionic conductivity by graphene-coating.

High-performance xLi2MnO3·(1-x)LiMn1/3Co1/3Ni1/3O2 (0.1 ⿤ x ⿤0.5) as Cathode Material for Lithium-ion Battery

Well-crystallized and high-performance xLi2MnO3·(1-x)LiMn1/3Co1/3Ni1/3O2 cathode materials over a wide compositional range (0.1⿤x⿤0.5) were prepared by a facile co-precipitation strategy. All samples show small and uniform particle dimensions in the range of 200-500nm. 0.3Li2MnO3·0.7LiMn1/3Co1/3Ni1/3O2 (LMNC3) delivers the highest discharge capacities of 321.1mAhg⿿1 at 0.1C, 305.2mAhg⿿1 at 0.2 C, 243.2mAhg⿿1 at 0.5C, 205.9mAhg⿿1 at 1C, 182.1mAhg⿿1 at 2C, and 133.7mAhg⿿1 at 5C, respectively. LMNC3 also exhibits an excellent fast charge-discharge performance, and even at a charge-discharge rate of 2C in the 100th cycle its capacity still remains 128.2mAhg⿿1. The improved performance of LMNC3 can be ascribed to the improvement of electrochemical reversibility, lithium ion diffusion and ionic conductivity. First-principles calculation based on density function theory reveals that the strong covalent bonds formed between Mn-3d and O-2p orbits and stable Li2MnO3-enriched layer are helpful for stabilizing the LiMn1/3Co1/3Ni1/3O2 structure. The same strategy adopted in this work could be helpful to develop other Li-rich cathodes with long cycle life and high rate performance.

Li5Cr7Ti6O25 as a novel negative electrode material for lithium-ion batteries.

Novel submicron Li5Cr7Ti6O25, which exhibits excellent rate capability, high cycling stability and fast charge-discharge performance is constructed using a facile sol-gel method. The insights obtained from this study will benefit the design of new negative electrode materials for lithium-ion batteries.

Enhanced fast charge–discharge performance of Li4Ti5O12 as anode materials for lithium-ion batteries by Ce and CeO2 modification using a facile method

Ce and CeO2in situ modified Li4Ti5O12 with fast charge–discharge performance for lithium-ion batteries were prepared by a solid-state method. The improved performance are found to be due to the increased ionic and electronic conductivity.

Rapid charge-discharge property of Li4Ti5O12-TiO2 nanosheet and nanotube composites as anode material for power lithium-ion batteries.

Well-defined Li4Ti5O12-TiO2 nanosheet and nanotube composites have been synthesized by a solvothermal process. The combination of in situ generated rutile-TiO2 in Li4Ti5O12 nanosheets or nanotubes is favorable for reducing the electrode polarization, and Li4Ti5O12-TiO2 nanocomposites show faster lithium insertion/extraction kinetics than that of pristine Li4Ti5O12 during cycling. Li4Ti5O12-TiO2 electrodes also display lower charge-transfer resistance and higher lithium diffusion coefficients than pristine Li4Ti5O12. Therefore, Li4Ti5O12-TiO2 electrodes display lower charge-transfer resistance and higher lithium diffusion coefficients. This reveals that the in situ TiO2 modification improves the electronic conductivity and electrochemical activity of the electrode in the local environment, resulting in its relatively higher capacity at high charge-discharge rate. Li4Ti5O12-TiO2 nanocomposite with a Li/Ti ratio of 3.8:5 exhibits the lowest charge-transfer resistance and the highest lithium diffusion coefficient among all samples, and it shows a much improved rate capability and specific capacity in comparison with pristine Li4Ti5O12 when charging and discharging at a 10 C rate. The improved high-rate capability, cycling stability, and fast charge-discharge performance of Li4Ti5O12-TiO2 nanocomposites can be ascribed to the improvement of electrochemical reversibility, lithium ion diffusion, and conductivity by in situ TiO2 modification.

Synthesis of LiNi0.5Mn1.5O4 cathode with excellent fast charge-discharge performance for lithium-ion battery

Well-defined LiNi0.5Mn1.5O4 powder has been synthesized by ethylene glycol (EG)-assisted oxalic acid co-precipitation method. The structure and physicochemical properties of this as-prepared powder were investigated by powder X-ray diffraction (XRD), Raman spectra (RS), scanning electron microscopy (SEM), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge–discharge test in detail. XRD shows impurity phase of LiyNi1-yO due to the oxygen loss reaction at high temperatures. SEM indicates that LiNi0.5Mn1.5O4 synthesized by EG-assisted method has a uniform and narrow size distribution under 1μm. RS confirms that both samples have Fd-3m space group. EIS and CV test exhibit that LiNi0.5Mn1.5O4 electrode synthesized by EG-assisted method has lower potential polarization, smaller charge transfer resistance, higher reversibility and larger lithium ion diffusion coefficient than the one obtained by ammonium hydroxide co-precipitation method. Galvanostatic charge–discharge test reveals that LiNi0.5Mn1.5O4 synthesized by EG-assisted method shows higher discharge capacity than that the one synthesized by ammonium hydroxide co-precipitation method at each rate.