Enhancing the Li+ diffusion in Li3VO4by coupling withreduced graphene oxide for lithium-ion batteries

2021 ◽  
Vol 17 ◽  
Author(s):  
Mingxuan Guo ◽  
Haibo Li
Keyword(s):  
Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Electronic Conductivity ◽  
Specific Capacity ◽  
Rate Capability ◽  
Lithium Ion ◽  
Reversible Capacity ◽  
Ion Diffusion ◽  
X Ray ◽  
Host Materials

Background: Owing to the excellent theoretical specific capacity and safety intercalation potential, Li3VO4¬ (LVO) has been proposed as anadvanced anode material for lithium ions batteries (LIBs). However, the LVO suffers from low electronic conductivity that limits its commercialization. Objective: The reduced graphene oxide (rGO) is recommended to couple with micro-LVO particles aiming to enhance the conductivity of compositeelectrodes. Method: The LVO@rGO compositeis synthesized by a facile hydrothermal method. The morphology, crystallinity, valance state and electrochemical behavior of LVO@rGO are characterized by scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and electrochemical workstation, respectively. Further, the LIBs’ performance is explored by making a coins-type half-cell LIBs battery via battery system. Results: The Li+ diffusion rate of the optimized LVO@rGO electrode is 7.67×10-23 cm2 s-1, which improves two orders of magnitudesof pure LVO electrode. As a result, the LVO@rGO anode delivers a reversible capacity of 190.1 mAh/g at 0.1 A/g after 100 cycles, which is even twice higher than that of pure LVO anode (90.6 mAh/g). Besides,it exhibitssuperior rate capability, i.e.a reversible capability of 285.0, 220.2, 158.7, 105.2 and 71.7 mAh/g at 0.05, 0.1, 0.2, 0.5 and 1.0 A/g, respectively. Conclusion: The high conductivity and flexible texture enable rGO an idea building block to enhance the Li ion diffusion of whole electrode. On the other hand, it is instrumental in alleviating the aggregation of host materials, leading to high specific surface and specific capacity.

Calcium Doping Effects on the Electrochemical Properties of LiFePO4/C Cathode Materials for Lithium-Ion Batteries

2012 ◽  
Vol 560-561 ◽  
pp. 499-505 ◽  
Author(s):  
George Ting Kuo Fey ◽  
Cyun Jhe Yan ◽  
Yi Chuan Lin ◽  
Kai Pin Huang ◽  
Yung Da Cho ◽  
...  
Keyword(s):  
Electrochemical Properties ◽  
Electronic Conductivity ◽  
Rate Capability ◽  
Lithium Ion ◽  
Ion Diffusion ◽  
Solid State Method ◽  
X Ray ◽  
Doping Effects ◽  
Li Ion ◽  
Calcium Doping

This Olivine LiFe1-xCaxPO4/C composites (x=0 - 0.014) were synthesized by a solid-state method using sebasic acid as a carbon source. The structure and electrochemical properties of the LiFe1-xCaxPO4/C compounds were studied. The X-ray diffractometer (XRD) results indicated that Ca2+ doping did not affect the structure of the samples, but the unit cell volume of doped sample are slightly increased. Electrochemical measurements showed that the LiFe0.99Ca0.01PO4/C composite delivered a discharge capacity of 149 mAh g-1 at a 0.2 C-rate between 4.0 and 2.8 V, probably due to the significant improvement of electronic conductivity and Li+ ion diffusion. Besides, the cell can sustain a 20 C-rate, and this rate capability is equivalent to charge or discharge in 3 min.

Ternary Composite of Molybdenum Disulfide-Graphene Oxide-Polyaniline for Supercapacitor

2021 ◽  
Author(s):  
Ke Qu ◽  
Yuqi Bai ◽  
Miao Deng
Keyword(s):  
Graphene Oxide ◽  
Molybdenum Disulfide ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Light Emitting Diode ◽  
Rate Capability ◽  
Energy Storage And Conversion ◽  
Carbon Paper ◽  
Power Sources ◽  
X Ray

Abstract The ever-increasing need for small and lightweight power sources for use in portable or wearable electronic devices has spurred the development of supercapacitors as a promising energy storage and conversion system. In this work, a simple, facile and easy-to-practice method has been developed to employ carbon paper (CP) as the support to coat molybdenum disulfide (MoS2) and graphene oxide (GO), followed by electrodeposition of polyaniline (PANI) to render CP/MoS2-GO-PANI. The preparation parameters, such as amounts of MoS2, GO and number of aniline electropolymerization cycles, have been optimized to render CP/MoS2-GO-PANI the best capacitive performance. The as-prepared optimal CP/MoS2-GO-PANI is characterized by X-ray powder diffraction, scanning electron microscopy, energy-dispersive spectroscopy, and X-ray photoelectron spectroscopy. The supercapacitive properties of CP/MoS2-GO-PANI as an electrode have been evaluated electrochemically via cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy testing. CP/MoS2-GO-PANI delivers a specific capacitance of 255.1 F/g at 1.0 A/g and exhibits excellent rate capability under larger current densities. Moreover, a symmetrical supercapacitor is assembled and three are connected in series to power a light-emitting diode for ~15 minutes, demonstrating the promising application potential of CP/MoS2-GO-PANI-based supercapacitor.

Constructing zigzag-like hollow mesoporous nanospheres MoO2/C with superior lithium storage performance

2021 ◽  
Author(s):  
Wencai Zhao ◽  
Y.F. Yuan ◽  
S.M. Yin ◽  
Gaoshen Cai ◽  
S.Y. Guo
Keyword(s):  
Reaction Kinetics ◽  
Discharge Capacity ◽  
Amorphous Carbon ◽  
Electronic Conductivity ◽  
Specific Capacity ◽  
Rate Capability ◽  
Lithium Ion ◽  
Structure Design ◽  
Structure Stability ◽  
Lithium Storage

Abstract Hollow mesoporous nanospheres MoO2/C are successfully constructed through metal chelating reaction between molybdenum acetylacetone and glycerol as well as the Kirkendall effect induced by diammonium hydrogen phosphate. MoO2 nanoparticles coupled by amorphous carbon are assembled to unique zigzag-like hollow mesoporous nanosphere with large specific surface area of 147.7 m2 g-1 and main pore size of 8.7 nm. The content of carbon is 9.1%. As anode material for lithium-ion batteries, the composite shows high specific capacity and excellent cycling performance. At 0.2 A g-1, average discharge capacity stabilizes at 1092 mAh g-1. At 1 A g-1 after 700 cycles, the discharge capacity still reaches 512 mAh g-1. Impressively, the composite preserves intact after 700 cycles. Even at 5 A g-1, the discharge capacity can reach 321 mAh g-1, exhibiting superior rate capability. Various kinetics analyses demonstrate that in electrochemical reaction, the proportion of the surface capacitive effect is higher, and the composite has relatively high diffusion coefficient of Li ions and fast faradic reaction kinetics. Excellent lithium storge performance is attributed to the synergistic effect of zigzag-like hollow mesoporous nanosphere and amorphous carbon, which improves reaction kinetics, structure stability and electronic conductivity of MoO2. The present work provides a new useful structure design strategy for advanced energy storage application of MoO2.

Synergistic effect between flake graphite and small-sized graphene in lithium storage

2021 ◽  
pp. 2150031
Author(s):  
Hai Li ◽  
Chunxiang Lu
Keyword(s):  
Synergistic Effect ◽  
Lithium Ion Batteries ◽  
Individual Component ◽  
Specific Capacity ◽  
Rate Capability ◽  
Lithium Ion ◽  
Reversible Capacity ◽  
Flake Graphite ◽  
Effective Strategy ◽  
Lithium Storage

As anode material for lithium-ion batteries, graphite has the disadvantage of relatively low specific capacity. In this work, a simple yet effective strategy to overcome the disadvantages by using a composite of flake graphite (FG) and small-sized graphene (SG) has been developed. The FG/SG composite prepared by dispersing FG and SG (90:10 w/w) in ethanol and drying delivers much higher specific capacity than that of individual component except for improved rate capability. More surprisingly, FG/SG composite delivers higher reversible capacity than its theoretical value calculated according to the theoretical capacities of graphite and graphene. Therefore, a synergistic effect between FG and SG in lithium storage is clearly discovered. To explain it, we propose a model that abundant nanoscopic cavities were formed due to physical adhesion between FG and SG and could accommodate extra lithium.

A Facile One-Pot Stepwise Hydrothermal Method for the Synthesis of 3D MoS2/RGO Composites with Improved Lithium Storage Properties

NANO ◽  
2019 ◽  
Vol 14 (03) ◽  
pp. 1950037 ◽  
Author(s):  
Bingning Wang ◽  
Xuehua Liu ◽  
Binghui Xu ◽  
Yanhui Li ◽  
Dan Xiu ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Electrochemical Performance ◽  
Hydrothermal Method ◽  
Hydrothermal Treatment ◽  
Active Material ◽  
Rate Capability ◽  
Lithium Ion ◽  
Reversible Capacity ◽  
Lithium Storage ◽  
One Pot

Three-dimensional reduced graphene oxide (RGO) matrix decorated with nanoflowers of layered MoS2 (denoted as 3D MoS2/RGO) have been synthesized via a facile one-pot stepwise hydrothermal method. Graphene oxide (GO) is used as precursor of RGO and a 3D GO network is formed in the first-step of hydrothermal treatment. At the second stage of hydrothermal treatment, nanoflowers of layered MoS2 form and anchor on the surface of previously formed 3D RGO network. In this preparation, thiourea not only induces the formation of the 3D architecture at a relatively low temperature, but also works as sulfur precursor of MoS2. The synthesized composites have been investigated with XRD, SEM, TEM, Raman spectra, TGA, N2 sorption technique and electrochemical measurements. In comparison with normal MoS2/RGO composites, the 3D MoS2/RGO composite shows improved electrochemical performance as anode material for lithium-ion batteries. A high reversible capacity of 930[Formula: see text]mAh[Formula: see text][Formula: see text][Formula: see text]g[Formula: see text] after 130 cycles under a current density of 200[Formula: see text]mA[Formula: see text][Formula: see text][Formula: see text]g[Formula: see text] as well as good rate capability and superior cyclic stability have been observed. The superior electrochemical performance of the 3D MoS2/RGO composite as anode active material for lithium-ion battery is ascribed to its robust 3D structures, enhanced surface area and the synergistic effect between graphene matrix and the MoS2 nanoflowers subunit.

Electrochemical Properties of Li0.99Gd0.01FePO4/C Composite Cathode for Lithium-Ion Batteries

2010 ◽  
Vol 146-147 ◽  
pp. 1233-1237
Author(s):  
Bin Sun ◽  
Yi Feng Chen ◽  
Kai Xiong Xiang ◽  
Wen Qiang Gong ◽  
Han Chen
Keyword(s):  
Specific Capacity ◽  
Rate Capability ◽  
Lithium Ion ◽  
Composite Cathode ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electrochemical Tests ◽  
Capacity Loss ◽  
Lattice Doping ◽  
Scanning Electron

Li0.99Gd0.01FePO4/C composite was prepared by solid-state reaction, using particle modification with amorphous carbon from the decomposition of glucose and lattice doping with supervalent cation Gd3+. All samples were characterized by X-ray diffraction, scanning electron microscopy, multi-point Brunauer Emmett and Teller methods. The electrochemical tests show Li0.99Gd 0.01FePO4/C composite obtains the highest discharge specific capacity of 154 mAh.g-1 at C/10 rate and the best rate capability. Its specific capacity reaches 131 mAh.g-1 at 2 C rate. Its capacity loss is only 14.9 % when the rate varies from C/10 to 2 C.

scholarly journals Facile Synthesis of Sn/Nitrogen-Doped Reduced Graphene Oxide Nanocomposites with Superb Lithium Storage Properties

Nanomaterials ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 1084 ◽  
Author(s):  
Quan Sun ◽  
Ying Huang ◽  
Shi Wu ◽  
Zhonghui Gao ◽  
Hang Liu ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Active Sites ◽  
Electronic Conductivity ◽  
Rate Capability ◽  
Lithium Ion ◽  
Discharge Process ◽  
Lithium Storage ◽  
Nitrogen Doped ◽  
Reduced Graphene

Sn/Nitrogen-doped reduced graphene oxide (Sn@N-G) composites have been successfully synthesized via a facile method for lithium-ion batteries. Compared with the Sn or Sn/graphene anodes, the Sn@N-G anode exhibits a superb rate capability of 535 mAh g−1 at 2C and cycling stability up to 300 cycles at 0.5C. The improved lithium-storage performance of Sn@N-G anode could be ascribed to the effective graphene wrapping, which accommodates the large volume change of Sn during the charge–discharge process, while the nitrogen doping increases the electronic conductivity of graphene, as well as provides a large number of active sites as reservoirs for Li+ storage.

Fabrication of Nickel Sulfide/Nitrogen-Doped Reduced Graphene Oxide Nanocomposite as Anode Material for Lithium-Ion Batteries and Its Electrochemical Performance

2020 ◽  
Vol 20 (11) ◽  
pp. 6782-6787
Author(s):  
Yeon-Ju Lee ◽  
Tae-Hyun Ha ◽  
Gyu-Bong Cho ◽  
Ki-Won Kim ◽  
Jou-Hyeon Ahn ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Lithium Ion ◽  
Treatment Method ◽  
Retention Capacity ◽  
Graphene Nanocomposites ◽  
X Ray ◽  
Nitrogen Doped ◽  
Reduced Graphene

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.

scholarly journals Complexing Agents on Carbon Content and Lithium Storage Capacity of LiFePO4/C Cathode Synthesized via Sol-Gel Approach

2016 ◽  
Vol 2016 ◽  
pp. 1-7
Author(s):  
C. Guan ◽  
H. Huang
Keyword(s):  
Discharge Rate ◽  
Sol Gel ◽  
Electronic Conductivity ◽  
Rate Capability ◽  
Lithium Ion ◽  
Cost Effective ◽  
Reversible Capacity ◽  
Complexing Agents ◽  
Lithium Storage ◽  
Synthesis Conditions

Olivine-structured LiFePO4faces its intrinsic challenges in terms of poor electrical conductivity and lithium-ion diffusion capability for application to lithium-ion batteries. Cost-effective sol-gel approach is advantageous to in situ synthesize carbon-coated LiFePO4(LiFePO4/C) which can not only improve electronic conductivity but also constrain particle size to nanometer scale. In this study, the key parameter is focused on the choice and amount of chelating agents in this synthesis route. It was found that stability of complexing compounds has significant impacts on the carbon contents and electrochemical properties of the products. At the favorable choice of precursors, composition, and synthesis conditions, nanocrystalline LiFePO4/C materials with appropriate amount of carbon coating were successfully obtained. A reversible capacity of 162 mAh/g was achieved at 0.2Crate, in addition to good discharge rate capability.

scholarly journals High Tap Density SphericalLi[Ni0.5Mn0.3Co0.2]O2Cathode Material Synthesized via Continuous Hydroxide Coprecipitation Method for Advanced Lithium-Ion Batteries

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Shunyi Yang ◽  
Xianyou Wang ◽  
Xiukang Yang ◽  
Ziling Liu ◽  
Qiliang Wei ◽  
...  
Keyword(s):  
Size Distribution ◽  
Photoelectron Spectroscopy ◽  
Rate Capability ◽  
Lithium Ion ◽  
X Ray Diffraction ◽  
Voltage Range ◽  
X Ray ◽  
Tap Density ◽  
Plate Shape ◽  
Hydroxide Coprecipitation

Spherical[Ni0.5Mn0.3Co0.2](OH)2precursor with narrow size distribution and high tap density has been successfully synthesized by a continuous hydroxide coprecipitation, andLi[Ni0.5Mn0.3Co0.2]O2is then prepared by mixing the precursor with 6% excessLi2CO3followed by calcinations. The tap density of the obtainedLi[Ni0.5Mn0.3Co0.2]O2powder is as high as 2.61 g cm−3. The powders are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), particle size distribution (PSD), and charge/discharge cycling. The XRD studies show that the preparedLi[Ni0.5Mn0.3Co0.2]O2has a well-ordered layered structure without any impurity phases. Good packing properties of spherical secondary particles (about 12 μm) consisted of a large number of tiny-thin plate-shape primary particles (less than 1 μm), which can be identified from the SEM observations. In the voltage range of 3.0–4.3 V and 2.5–4.6 V,Li[Ni0.5Mn0.3Co0.2]O2delivers the initial discharge capacity of approximately 175 and 214 mAh g−1at a current density of 32 mA g−1, and the capacity retention after 50 cycles reaches 98.8% and 90.2%, respectively. Besides, it displays good high-temperature characteristics and excellent rate capability.

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