scholarly journals Thermal Decomposition Study on Li2O2 for Li2NiO2 Synthesis as a Sacrificing Positive Additive of Lithium-Ion Batteries

Molecules ◽  
2019 ◽  
Vol 24 (24) ◽  
pp. 4624 ◽  
Author(s):  
Jaekwang Kim ◽  
Hyunchul Kang ◽  
Keebum Hwang ◽  
Songhun Yoon

Herein, thermal decomposition experiments of lithium peroxide (Li2O2) were performed to prepare a precursor (Li2O) for sacrificing cathode material, Li2NiO2. The Li2O2 was prepared by a hydrometallurgical reaction between LiOH·H2O and H2O2. The overall reaction during annealing was found to involve the following three steps: (1) dehydration of LiOH·H2O, (2) decomposition of Li2O2, and (3) pyrolysis of the remaining anhydrous LiOH. This stepwise reaction was elucidated by thermal gravimetric and quantitative X-ray diffraction analyses. Furthermore, over-lithiated lithium nickel oxide (Li2NiO2) using our lithium precursor was synthesized, which exhibited a larger yield of 90.9% and higher irreversible capacity of 261 to 265 mAh g−1 than the sample prepared by commercially purchased Li2O (45.6% and 177 to 185 mAh g−1, respectively) due to optimal powder preparation conditions.

2016 ◽  
Vol 78 (5-10) ◽  
Author(s):  
Hafizah Rajaa Shaari ◽  
V. Sethuprakhash ◽  
Wan Jeffry Basirun

LiNixV1-x-y AlyO2, are cathode materials for lithium ion batteries which have been synthesized via carbon combustion method. Lithium nickel oxide derivatives are considered by the battery manufacturers to be very promising for application in 4V lithium-ion batteries. The objective of this study is, to successfully synthesize a lithium nickel vanadium aluminum oxide cathode which can show intercalation and de-intercalation process during cyclic voltammetry testing and a discharge capacity of above 50mAh/g. LiNi1-x-yVxAlyO2were synthesized by the carbon combustion method using acetylene carbon black as a binder. X-Ray Diffraction (XRD) reveals extra peaks related to Vanadium metal when it is added into LiNiAlO2. The intensity peak of the spectrum increased when the V content is increased. Scanning Electron Microscopy (SEM) shows the grain particles become non-spherical and flakes when more vanadium substituted for nickel in the sample. Fourier Transform Infrared (FTIR) spectroscopy analysis and Energy dispersive analysis of X-Ray (EDAX) confirmed that NO3- impurities are not present and composition in samples Galvanostatic charge/discharge data obtained illustrates a discharge capacity of 80.57mAh/g LiNi0.8V0.1Al0.1O2 and an average of 80.55mAh/g for 10 cycles whereas LiNi0.6V0.3Al 0.1O2 highest discharge capacity is 80.52mAh/g and also an average of 80.53mAh/g for 10 cycles. Voltammographs of the LiNi0.8V0.1Al0.1O2, LiNi0.7V0.2Al0.1O2 and LiNi0.6V0.3Al0.1O2 materials showed good oxidation and reduction loop at 0.05mV/s and 1 mV/s scan rate.


Author(s):  
U. Aebi ◽  
R. Millonig ◽  
H. Salvo

To date, most 3-D reconstructions of undecorated actin filaments have been obtained from actin filament paracrystal data (for refs, see 1,2). However, due to the fact that (a) the paracrystals may be several filament layers thick, and (b) adjacent filaments may sustantially interdigitate, these reconstructions may be subject to significant artifacts. None of these reconstructions has permitted unambiguous tracing or orientation of the actin subunits within the filament. Furthermore, measured values for the maximal filament diameter both determined by EM and by X-ray diffraction analysis, vary between 6 and 10 nm. Obviously, the apparent diameter of the actin filament revealed in the EM will critically depend on specimen preparation, since it is a rather flexible supramolecular assembly which can easily be bent or distorted. To resolve some of these ambiguities, we have explored specimen preparation conditions which may preserve single filaments sufficiently straight and helically ordered to be suitable for single filament 3-D reconstructions, possibly revealing molecular detail.


Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3502
Author(s):  
Fangzhou Song ◽  
Masayoshi Uematsu ◽  
Takeshi Yabutsuka ◽  
Takeshi Yao ◽  
Shigeomi Takai

LATP-based composite electrolytes were prepared by sintering the mixtures of LATP precursor and La2O3 nano-powder. Powder X-ray diffraction and scanning electron microscopy suggest that La2O3 can react with LATP during sintering to form fine LaPO4 particles that are dispersed in the LATP matrix. The room temperature conductivity initially increases with La2O3 nano-powder addition showing the maximum of 0.69 mS∙cm−1 at 6 wt.%, above which, conductivity decreases with the introduction of La2O3. The activation energy of conductivity is not largely varied with the La2O3 content, suggesting that the conduction mechanism is essentially preserved despite LaPO4 dispersion. In comparison with the previously reported LATP-LLTO system, although some unidentified impurity slightly reduces the conductivity maximum, the fine dispersion of LaPO4 particles can be achieved in the LATP–La2O3 system.


2012 ◽  
Vol 736 ◽  
pp. 127-132
Author(s):  
Kuldeep Rana ◽  
Anjan Sil ◽  
Subrata Ray

Lithium alloying compounds as an anode materials have been a focused for high capacity lithium ion battery due to their highenergy capacity and safety characteristics. Here we report on the preparation of graphite-tin composite by using ball-milling in liquid media. The composite material has been characterized by scanning electron microscope, energy depressive X-ray spectroscopy, X-ray diffraction and Raman spectra. The lithium-ion cell made from graphite-tin composite presented initial discharge capacity of 1065 mAh/g and charge capacity 538 mAh/g, which becomes 528 mAh/g in the second cycle. The composite of graphite-tin with higher capacity compared to pristine graphite is a promising alternative anode material for lithium-ion battery.


2021 ◽  
Vol 507 ◽  
pp. 230253
Author(s):  
Harry Charalambous ◽  
Daniel P. Abraham ◽  
Alison R. Dunlop ◽  
Stephen E. Trask ◽  
Andrew N. Jansen ◽  
...  
Keyword(s):  

2013 ◽  
Vol 787 ◽  
pp. 58-64 ◽  
Author(s):  
Xiang Feng Li ◽  
Zhao Zhang ◽  
Fang Liu ◽  
Shu Ping Zheng

The LiFePO4/C composites with different morphology are synthesized by a novel glucose assisted hydrothermal method at various glucose concentrations (from 0 to 0.25mol/L) and the insoluble lithium source Li2CO3, (NH4)2Fe (SO4)2·6H2O and (NH4)2HPO4(n (Li):n (Fe):n (P)=1:1:1) are used as raw materials. The structure, morphology, thermal performance and electrochemical properties of the synthesized composites are characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), thermogravimetry/differential scanning calorimetry (TG-DSC), galvanostatic charge/discharge tests and cyclic voltammetry (CV). The results show that the LiFePO4/C synthesized with 0.125mol/L glucose has the relatively small particles size (0.1~0.5μm) and the well spherical morphology. The optimal sample exhibits a high discharge capacity of 160.0mAh/g at the first cycle and exhibits a good reversibility and stability in CV tests.


2007 ◽  
Vol 336-338 ◽  
pp. 463-465 ◽  
Author(s):  
Xin Lu Li ◽  
Fei Yu Kang ◽  
Yong Ping Zheng ◽  
Xiu Juan Shi ◽  
Wan Ci Shen

Partial oxygen in LiNi0.7Co0.3O2 was replaced by chlorine to form LiNi0.7Co0.3O1.9Cl0.1. Phase structure of LiNi0.7Co0.3O1.9Cl0.1 was identified as a pure hexagonal lattice of α-NaFeO2 type by X-ray diffraction. Discharge capacity of LiNi0.7Co0.3O1.9Cl0.1 was 202 mAh/g in initial cycle at 15 mA/g current density in 2.5- 4.3 V potential window. The constant current charge/discharge experiments and cyclic voltammograms showed that chlorine addition was effective to improve reversible capacity and cycle stability of LiNi0.7Co0.3O2.


Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2457 ◽  
Author(s):  
Haifeng Zhao ◽  
Jing Lv ◽  
Junshan Sang ◽  
Li Zhu ◽  
Peng Zheng ◽  
...  

In this work, a mixing-calcination method was developed to facilely construct MXene/CuO nanocomposite. CuO and MXene were first dispersed in ethanol with sufficient mixing. After solvent evaporation, the dried mixture was calcinated under argon to produce a MXene/CuO nanocomposite. As characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and X-ray photoelectron spectra (XPS), CuO nanoparticles (60–100 nm) were uniformly distributed on the surface and edge of MXene nanosheets. Furthermore, as evaluated by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA), the high-temperature decomposition (HTD) temperature decrease of ammonium perchlorate (AP) upon addition of 1 wt% CuO (hybridized with 1 wt% MXene) was comparable with that of 2 wt% CuO alone, suggesting an enhanced catalytic activity of CuO on thermal decomposition of AP upon hybridization with MXene nanosheets. This strategy could be further applied to construct other MXene/transition metal oxide (MXene/TMO) composites with improved performance for various applications.


Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 281
Author(s):  
Daniil Aleksandrov ◽  
Pavel Novikov ◽  
Anatoliy Popovich ◽  
Qingsheng Wang

Solid-state reaction was used for Li7La3Zr2O12 material synthesis from Li2CO3, La2O3 and ZrO2 powders. Phase investigation of Li7La3Zr2O12 was carried out by x-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDS) methods. The thermodynamic characteristics were investigated by calorimetry measurements. The molar heat capacity (Cp,m), the standard enthalpy of formation from binary compounds (ΔoxHLLZO) and from elements (ΔfHLLZO), entropy (S0298), the Gibbs free energy of the Li7La3Zr2O12 formation (∆f G0298) and the Gibbs free energy of the LLZO reaction with metallic Li (∆rGLLZO/Li) were determined. The corresponding values are Cp,m = 518.135 + 0.599 × T − 8.339 × T−2, (temperature range is 298–800 K), ΔoxHLLZO = −186.4 kJ·mol−1, ΔfHLLZO = −9327.65 ± 7.9 kJ·mol−1, S0298 = 362.3 J·mol−1·K−1, ∆f G0298 = −9435.6 kJ·mol−1, and ∆rGLLZO/Li = 8.2 kJ·mol−1, respectively. Thermodynamic performance shows the possibility of Li7La3Zr2O12 usage in lithium-ion batteries.


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