scholarly journals Effect of Structural and Electrochemical Properties of Yttrium-doped LiNi0.90Co0.05Al0.05O2 Electrode by Co-precipitation for Lithium Ion-batteries

2015 ◽  
Vol 18 (1) ◽  
pp. 009-016 ◽  
Author(s):  
Gi-Won Yoo ◽  
Tae-Jun Tae-Jun Park ◽  
Jong-Tae Son

In this study, the LiNi0.90−xCo0.05Al0.05YxO2 (x = 0, 0.025, 0.075) have been synthesized by a co-precipitation and solid-state reaction method. The effect of the Y3+-doping on the structural and electrochemical properties were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and by electrochemical and impedance spectroscopy (EIS). From the results of the XRD pattern changes between before and after the doping, less cation mixing and more ordered hexagonal structure were observed for the LiNi0.875Co0.05Al0.05Y0.025O2 cathode and the cell delivered an initial discharge capacity of 195.8 mAhg-1 and was 10.2 mAhg-1 higher than the pristine cell by yttrium doping effect. High rate capability studies were also performed and showed the capacity retention of 95, 81.7 and 63.8 % at 0.2, 1.0 and 5.0 C-rate, respectively during the cycling. The impedance spectra showed that the charge transfer resistance for the pristine cathode grew significantly, while that for the Y3+-doped cathode decreased during cycling. It was concluded that the capacity fading for LiNi0.90Co0.05Al0.05O2 mainly due to the cation mixing, partially contributed by the impedance growth and by doping the pristine material with Y3+, cation mixing can be efficiently suppressed, which results in the improved rate capability.

2019 ◽  
Vol 12 (01) ◽  
pp. 1850104 ◽  
Author(s):  
Jinggao Wu ◽  
Qi Lai ◽  
Canyu Zhong

MoO3@CoMoO4 hybrid is fabricated by a facile one-step hydrothermal method and is used as anode for lithium-ion battery (LIB). Compared to pristine MoO3, galvanostatic charge–discharge tests show that the hybrid electrode delivered a remarkable rate capability of 586.69[Formula: see text]mAh[Formula: see text]g[Formula: see text] at the high current density of 1000[Formula: see text]mA[Formula: see text]g[Formula: see text] and a greatly enhanced cyclic capacity of 887.36[Formula: see text]mA[Formula: see text]h[Formula: see text]g[Formula: see text] after 140 cycles at the current density of 200[Formula: see text]mA[Formula: see text]g[Formula: see text] (with capacity retention, 85.3%). The superior electrochemical properties could be ascribed to the synergistic effect of MoO3 and CoO nanostructure that results in the lower charge transfer resistance and the higher Li[Formula: see text] diffusion coefficient, thus leading to high performance Li[Formula: see text] reversibility storage.


NANO ◽  
2020 ◽  
pp. 2150005
Author(s):  
Meng Sun ◽  
Zhipeng Cui ◽  
Huanqing Liu ◽  
Sijie Li ◽  
Qingye Zhang ◽  
...  

FeOOH nanorods (NRs) wrapped by reduced graphene oxide (rGO) were fabricated using a facile solvothermal method. When used as anode materials for lithium-ion batteries (LIBs), the FeOOH NRs/rGO composites show a higher capacity (490[Formula: see text]mAh g[Formula: see text] after 100 cycles at a current density of 100[Formula: see text]mA g[Formula: see text] and better rate capability than pure FeOOH NRs. The enhanced electrochemical performance can be ascribed to the hybrid structure of FeOOH and rGO. On one hand, the introduction of rGO can improve electronic conductivity and reduce charge-transfer resistance for electrode materials. On the other hand, the distinctive structure (FeOOH NRs surrounded by flexible rGO) can effectively buffer large volume change during the Li[Formula: see text] insertion/extraction process. Our work provides a feasible strategy to obtain high-performance LIBs.


Energies ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1308 ◽  
Author(s):  
Anil Yedluri ◽  
Eswar Araveeti ◽  
Hee-Je Kim

NiCo2O4 nanoleaf arrays (NCO NLAs) and NiCo2O4/NiCO2O4 nanofile arrays (NCO/NCO NFAs) material was fabricated on flexible nickel foam (NF) using a facile hydrothermal approach. The electrochemical performance, including the specific capacitance, charge/discharge cycles, and lifecycle of the material after the hydrothermal treatment, was assessed. The morphological and structural behaviors of the NF@NCO NLAs and NF@NCO/NCO NFAs electrodes were analyzed using a range of analysis techniques. The as-obtained nanocomposite of the NF@NCO/NCO NFAs material delivered outstanding electrochemical performance, including an ultrahigh specific capacitance (Cs) of 2312 F g−1 at a current density of 2 mA cm−2, along with excellent cycling stability (98.7% capacitance retention after 5000 cycles at 5 mA cm−2). These values were higher than those of NF@NCO NLAs (Cs of 1950 F g−1 and 96.3% retention). The enhanced specific capacitance was attributed to the large electrochemical surface area, which allows for higher electrical conductivity and rapid transport between the electrons and ions as well as a much lower charge-transfer resistance and superior rate capability. These results clearly show that a combination of two types of binary metal oxides could be favorable for improving electrochemical performance and is expected to play a major role in the future development of nanofile-like composites (NF@NCO/NCO NFAs) for supercapacitor applications.


2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Jialiang Tang ◽  
Vinodkumar Etacheri ◽  
Vilas G. Pol

Abstract The conversion of allergic pollen grains into carbon microstructures was carried out through a facile, one-step, solid-state pyrolysis process in an inert atmosphere. The as-prepared carbonaceous particles were further air activated at 300 °C and then evaluated as lithium ion battery anodes at room (25 °C) and elevated (50 °C) temperatures. The distinct morphologies of bee pollens and cattail pollens are resembled on the final architecture of produced carbons. Scanning Electron Microscopy images shows that activated bee pollen carbon (ABP) is comprised of spiky, brain-like and tiny spheres; while activated cattail pollen carbon (ACP) resembles deflated spheres. Structural analysis through X-ray diffraction and Raman spectroscopy confirmed their amorphous nature. X-ray photoelectron spectroscopy analysis of ABP and ACP confirmed that both samples contain high levels of oxygen and small amount of nitrogen contents. At C/10 rate, ACP electrode delivered high specific lithium storage reversible capacities (590 mAh/g at 50 °C and 382 mAh/g at 25 °C) and also exhibited excellent high rate capabilities. Through electrochemical impedance spectroscopy studies, improved performance of ACP is attributed to its lower charge transfer resistance than ABP. Current studies demonstrate that morphologically distinct renewable pollens could produce carbon architectures for anode applications in energy storage devices.


2020 ◽  
Vol 12 (4) ◽  
pp. 486-491
Author(s):  
Jinlei Wang ◽  
Na Cao ◽  
Huiling Du ◽  
Xian Du ◽  
Hai Lu ◽  
...  

Metal-organic frameworks (MOFs) have recently emerged as promising electrode materials for lithium-ion batteries (LIBs). However, poor electrical conductivity in most MOFs limits their electrochemical performance. In this work, the integration of flaky cobalt 1,4-benzenedicarboxylate (Co-BDC) MOF with conductive polypyrrole (PPy) nanofibers via in-situ growth strategy was explored for developing novel anode materials for LIBs. Electrochemical studies showed that PPy/Co-BDC composites exhibited enhanced cycling performance (a reversible capacity of ca. 364 mA h g–1 at a current density of 50 mA g–1 after 100 cycles) and rate capability, com- pared with the pristine Co-BDC. The well dispersion of Co-BDC on polypyrrole nanofibers and the decrease in charge-transfer resistance of the composite electrodes accounted for the improvement of electrochemical properties.


2016 ◽  
Vol 835 ◽  
pp. 126-130 ◽  
Author(s):  
Kyoung Soo Park ◽  
Soon Ki Jeong ◽  
Yang Soo Kim

The electrochemical properties of niobium monoxide, NbO, were investigated as a negative electrode material for lithium-ion batteries. Lithium ions were inserted into and extracted from NbO material at potentials < 1.0 V versus Li/Li+, involving formation of a solid electrolyte interface (SEI) on the NbO surface in the first cycle. Its reversible capacity is ~67 mAh g–1 with the capacity retention of ~109% after 50 cycles. The magnitude of charge transfer resistance was greatly decreased by ball-milling the pristine NbO, whereas the ball-milling had no effect on the SEI resistance.


Author(s):  
Le Phan Cam Linh ◽  
Nguyen Van Ky ◽  
Pham Duy Long ◽  
Giang Hong Thai ◽  
Dang Thi Thanh Le ◽  
...  

In this study, Li1-xNaxMn0.5Ni0.5O2 materials were successfully synthesized by co-precipitation following by solid state reaction method. X-ray powder diffraction analyses showed that the Li1-xNaxMn0.5Ni0.5O2 materials were single-phase and crystallized in a rhombohedral structure with a space group of R–3m at Na substitution concentrations of 0–20%. When increasing the concentration of Na substitution to 30%, diffraction peaks of Na2Mn3O7 as an impurity phase appeared in the X-ray diffraction pattern of the synthesized material. Rietveld refinements of the X-ray diffraction patterns revealed that the substitutions of Na for Li resulted in significant increments of the lattice constant c and slight increments of the lattice constant a. The results of galvanostatic charge/discharge measurements showed that the substitutions reduced the specific capacity but improved the rate capability of the Li0.8Na0.2Mn0.5Ni0.5O2 in comparison with the LiMn0.5Ni0.5O2 material.


2013 ◽  
Vol 737 ◽  
pp. 80-84 ◽  
Author(s):  
Arenst Andreas Arie ◽  
Joong Kee Lee

Silicon would seem to be a possible candidate to replace graphite or carbon as anode materials for lithium ion batteries based on its potential high capacity of 4200 mAhg-1. The main problem that must be solved for commercial application of silicon as anode material was the poor cyclic performance due to severe volume expansion during repeated charged-discharged cycles and its low electrical conductivity. In this work, we proposed Phosphorus doped (P-doped) Si films as anodes in lithium ion batteries. The electrochemical properties of the silicon based electrodes were examined by means of charge-discharge and impedance test. In comparison with the bare silicon electrode, the P type silicon electrode exhibited higher specific capacity of 2585 mAhg-1 until the 50th cycle. It was attributed to the improved electrical conductivity of Si film and reduced charge transfer resistance


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