Enhanced electrochemical performance of SnS nanoparticles/CNTs composite as anode material for sodium-ion battery

SnS/CNTs composite as anode for SIBs exhibits high reversible capacity, good cyclability as well as rate performance, which is superior to that of pure SnS. The enhanced electrochemical performance can be attributed to the adding of CNTs as a flexible and conductive structure supporter and the formation of SnS nanoparticles with small diameter.     

Facile synthesized Cu-SnO2 anode materials with three-dimensional metal cluster conducting architecture for high performance lithium-ion batteries

A novel Cu-SnO₂ anode material derived from Cu₆Sn₅ alloy, retaining high conductivity of Cu and high theoretical capacity of SnO₂ with a facile synthesizing process by oxidation and reduction method. The novel Cu structure penetrates in the composite particles inducing high conductivity and spaceconfined SnO₂, which restrict the pulverization of SnO₂ during lithiation/delithiation process.     

Vertical crosslinking MoS2/three-dimensional graphene composite towards high performance supercapacitor

The vertical crosslinking MoS₂/three-dimensional graphene composite has been prepared by hydrothermal method, which delivered a superior and stable electrochemical capacitive performance.     

Protection of Li metal anode by surface-coating of PVDF thin film to enhance the cycling performance of Li batteries

The PVDF thin film on the surface of the lithium metal can highly suppress the lithium dendrites.     

Nano-LiCoO2 as cathode material of large capacity and high rate capability for aqueous rechargeable lithium batteries

Crystalline nanoparticles of LiCoO₂ are prepared by a sol–gel method at 550 °C and characterized by X-ray diffraction. Their electrochemical behaviors were characterized by cyclic voltammograms, capacity measurement and cycling performance. Results show that the reversible capacity of the nano-LiCoO₂ can be up to 143 mAh/g at 1000 mA/g and still be 133 mAh/g at 10,000 mA/g (about 70C) in 0.5 mol/l Li₂SO₄ aqueous electrolyte. In addition, their cycling behavior is also very satisfactory, no evident capacity fading during the initial 40 cycles. These data present great promise for the application of aqueous rechargeable lithium batteries.     

Bismuth oxide nanoflake@carbon film: A free-standing battery-type electrode for aqueous sodium ion hybrid supercapacitors

An efficient strategy is developed to fabricate binder-free Bi₂O₃@C nanoflake film anode, which is utilized to assemble a high-performance aqueous sodium ion hybrid supercapacitor.     

Ether-based electrolyte enabled Na/FeS2 rechargeable batteries

We demonstrate for the first time that by simply substituting ether-based electrolyte (1.0 M NaCF₃SO₃ in diglyme) for the commonly used carbonate-based electrolyte, the cyclability of FeS₂ towards sodium storage can be significantly improved. A sodiation capacity over 600 mAh/g and a discharge energy density higher than 750 Wh/kg are obtained for FeS₂ at 20 mA/g. When tested at 60 mA/g, FeS₂ presents a sodiation capacity of 530 mAh/g and retains 450 mAh/g after 100 cycles, much better than the cycling performance of Na/FeS₂ tested in carbonate-based electrolyte.     

A Co(OH)2−graphene nanosheets composite as a high performance anode material for rechargeable lithium batteries

A Co(OH)₂?graphene nanosheets (Co(OH)₂?GNS) composite as a high performance anode material was firstly prepared through a simultaneous hydrothermal method. The structure, morphology and electrochemical performance of the obtained samples were systematically investigated by X-ray diffraction (XRD), transmission electron microscope (TEM) and electrochemical measurements. According to the TEM analysis, the surface of the Co(OH)₂ is surrounded with GNS in the Co(OH)₂?GNS composite. The specific discharge (lithiation) and charge (delithiation) capacities of Co(OH)₂?GNS attain to 1599 and 1120 mAh/g at a current density of 200 mA/g in the first cycle, respectively. After 30 cycles, the reversible capacity of Co(OH)₂?GNS is still 910 mAh/g with the retention of 82%. The particular structure of Co(OH)₂ particles surrounded by the GNS could limit the volume change during cycling and provide an excellent electronic conduction pathway, which could be the main reason for the remarkable improvement of electrochemical performance.     

MOF-derived ZnCo2O4/C wrapped on carbon fiber as anode materials for structural lithium-ion batteries

In this work, large area MOF-derived ZnCo₂O₄/C anchored on carbon fiber as high-performance anode materials was fabricated via a facile method and subsequent annealing treatment.     

Carbon-coated manganese dioxide nanoparticles and their enhanced electrochemical properties for zinc-ion battery applications

In this study, we report the cost-effective and simple synthesis of carbon-coated α-MnO_2nanoparticles(α-MnO_2@C) for use as cathodes of aqueous zinc-ion batteries(ZIBs) for the first time. α-MnO_2@C was prepared via a gel formation, using maleic acid(C_4H_4O_4) as the carbon source, followed by annealing at low temperature of 270 °C. A uniform carbon network among the α-MnO_2 nanoparticles was observed by transmission electron microscopy. When tested in a zinc cell, the α-MnO_2@C exhibited a high initial discharge capacity of 272 m Ah/g under 66 m A/g current density compared to 213 m Ah/g, at the same current density, displayed by the pristine sample. Further, α-MnO_2@C demonstrated superior cycleability compared to the pristine samples. This study may pave the way for the utilizing carbon-coated MnO_2 electrodes for aqueous ZIB applications and thereby contribute to realizing high performance eco-friendly batteries.     

Porous nanocomposite derived from Zn,Ni-bimetallic metal-organic framework as an anode material for lithium-ion batteries

A highly stable and Zn, Ni-bimetallic porous composite was synthesized via a one-step pyrolysis of a bimetal-organic framework as an efficient anode material for lithium-ion batteries. Remarkably the obtained composite shows 1105.2 mAh/g at a current density of 5000 mA/g after 400 cycles which makes it a promising candidate to improve the volumetric energy density.     

Flexible asymmetric supercapacitor based on MnO2 honeycomb structure

By controlling the electroplating time of solution containing Mn(Ac)₂, the MnO₂ nanosheets were self-assembled to the honeycomb structure and showed an excellent electrochemical performance in 1 mol/L Na₂SO₄ electrolyte. Via pairing with activated carbon as negative electrode, the capacitor could deliver a maximum energy density of 43.84 Wh/kg and a maximum power density of 6.62 kW/kg.     

High-performance Na1.25V3O8 nanosheets for aqueous zinc-ion battery by electrochemical induced de-sodium at high voltage

Aqueous rechargeable zinc-ion batteries (ARZIBs) are expected to replace organic electrolyte batteries owing to its low price, safe and environmentally friendly characteristics. Herein, we fabricated vanadium-based Na_1.25V₃O₈ nanosheets as a cathode material for ARZIBs, which present a high performance by electrochemical de-sodium at high voltage to form Na₂V₆O₁₆ phase in the first cycle: high capacity of 390 mAh/g at 0.1 A/g, high rate performance (162 mAh/g at 10 A/g) and superior cycle stability (179 mAh/g with a high capacity retention of 88.2% of the maximum capacity after 2000 cycles). In addition, the cell exhibits a high energy density of 416.9 Wh/kg at 143.6 W/kg, suggesting great potential of the as-prepared Na_1.25V₃O₈ nanosheets for ARZIBs     

Low-temperature performance of LiFePO4/C cathode in a quaternary carbonate-based electrolyte

The low-temperature performance of LiFePO₄/C cathode in a quaternary carbonate-based electrolyte (1.0 M LiPF₆/EC+DMC+DEC+EMC (1:1:1:3, v/v)) was studied. The discharge capacities of the LiFePO₄/C cathode were about 134.5 mAh/g (20 °C), 114 mAh/g (0 °C), 90 mAh/g (−20 °C) and 69 mAh/g (−40 °C) using a 1C charge–discharge rate. Cyclic voltammetry measurements show obviously sluggish of the lithium insertion–extraction process of the LiFePO₄/C cathode as the operation temperature falls below −20 °C. Electrochemical impedance analyses demonstrate that the sluggish of charge-transfer reaction on the electrolyte/LiFePO₄/C interface and the decrease of lithium diffusion capability in the bulk LiFePO₄ was the main performance limiting factors at low-temperature.     

Hollow Co9S8 from metal organic framework supported on rGO as electrode material for highly stable supercapacitors

We demonstrate a hydrothermal method to fabricate a composite of reduced graphene oxide (rGO) with hollow Co₉S₈ derived from metal organic framework (MOF), which exhibits a high specific capacitance of 575.9 F/g at 2 A/g and 92.0% capacitance retention after 9000 cycles.     

Mesoporous tubular graphene electrode for high performance supercapacitor

Mesopores tubular graphene, synthesized by template method, have unique bi-directional ions transfer channel in unstack graphene layers and high mesopore ratio, exhibiting excellent capacitance performance in the EDLC using ionic liquid electrolyte at 4 V.     

Polyimide-derived carbon nanofiber membranes as anodes for high-performance flexible lithium ion batteries

Heteroatoms-doped carbon nanofiber membranes with flexible features were prepared by electrospinning with heterocyclic polyimide (PI) structures containing biphenyl and pyrimidine rings. The products with optimized treatment could achieve 695 mAh/g at 0.1 A/g and retain 245 mAh/g at 1.5 A/g after 300 cycles when used as anode for Li-ion batteries.     

Anomalous capacity and cycling stability of xLi2MnO3 · (1 − x)LiMO2 electrodes (M = Mn,Ni, Co) in lithium batteries at 50 °C

Transition metal oxides with composite xLi₂MnO₃ ·  (1 − x)LiMO₂ rocksalt structures (M = Mn, Ni, Co) are of interest as a new generation of cathode materials for high energy density lithium-ion batteries. After electrochemical activation to 4.6 or 4.8 V (vs. Li⁰) at 50 °C, xLi₂MnO₃ · (1 − x)LiMn_0.33Ni_0.33Co_0.33O₂ (x = 0.5, 0.7) electrodes deliver initial discharge capacities (>300 mAh/g) at a low current rate (0.05 mA/cm²) that exceed the theoretical values for lithiation back to the rocksalt stoichiometry (240–260 mAh/g), at least during the early charge/discharge cycles of the cells. Attention is drawn to previous reports of similar, but unaccounted and unexplained anomalous behavior of these types of electrode materials. Possible reasons for this anomalous capacity are suggested. Indications are that electrodes in which M = Mn, Ni and Co do not cycle with the same stability at 50 °C as those without cobalt.     

Co1-xS embedded in porous carbon derived from metal organic framework as a highly efficient electrocatalyst for oxygen evolution reaction

Here, we report a two-step conversion method to fabricate a composite of Co_1-xS embedded in porous carbon framework (Co_1-xS@C) derived from metal organic frameworks (MOFs). The as-prepared porous dodecahedron Co_1-xS@C composite catalyst exhibits excellent electrocatalytic performance towards oxygen evolution reaction (OER).     

Laser processed micro-supercapacitors based on carbon nanotubes/manganese dioxide nanosheets composite with excellent electrochemical performance and aesthetic property

A laser processed micro-supercapacitor (LPMS) based on carbon nanotubes/manganese dioxide composite is fabricated through slurry dispensing and laser scribing techniques. This device presents superior electrochemical performance and aesthetic property.