scholarly journals Synthesis and Electrochemical Properties of TiNb2O7 and Ti2Nb10O29 Anodes under Various Annealing Atmospheres

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 983
Author(s):  
Touraj Adhami ◽  
Reza Ebrahimi-Kahrizsangi ◽  
Hamid Reza Bakhsheshi-Rad ◽  
Somayeh Majidi ◽  
Milad Ghorbanzadeh ◽  
...  

In this study, two compounds of TiNb2O7 and Ti2Nb10O29 were successfully synthesized by mechanochemical method and post-annealing as an anode material for lithium-ion batteries. The effect of annealing atmosphere on the morphology, particle size, and electrochemical characteristics of two compounds was investigated. For these purposes, the reactive materials were milled under an argon atmosphere with a certain mole ratio. Subsequently, each sample was subjected to annealing treatment in two different atmospheres, namely argon and oxygen. Phase and morphology identifications were carried out by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) to identify the phases and evaluate the morphology of the synthesized samples. The charging and discharging tests were conducted using a battery-analyzing device to evaluate the electrochemical properties of the fabricated anodes. Annealing in different atmospheres resulted in variable discharge capacities so that the two compounds of TiNb2O7 and Ti2Nb10O29 annealed under the argon atmosphere showed a capacity of 60 and 66 mAh/g after 179 cycles, respectively, which had a lower capacity than their counterpart under the oxygen atmosphere. The final capacity of the annealed samples in the oxygen atmosphere is 72 and 74 mAh/g, respectively.

Polymers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 126 ◽  
Author(s):  
Pei-Chi Cheng ◽  
Bing-Han Li ◽  
Feng-Shuen Tseng ◽  
Po-Ching Liang ◽  
Chia-Her Lin ◽  
...  

Four lithium coordination polymers, [Li3(BTC)(H2O)6] (1), [Li3(BTC)(H2O)5] (2), [Li3(BTC)(μ2-H2O)] (3), and [Li(H2BTC)(H2O)] (4) (H3BTC = 1,3,5-benzenetricarboxylatic acid), have been synthesized and characterized. All the structures have been determined using single crystal X-ray diffraction studies. Complexes 1 and 2 have two-dimensional (2-D) sheets, whereas complex 3 has three-dimensional (3-D) frameworks and complex 4 has one-dimensional (1-D) tubular chains. The crystal-to-crystal transformation was observed in 1–3 upon removal of water molecules, which accompanied the changes in structures and ligand bridging modes. Furthermore, the electrochemical properties of complexes 3 and 4 have been studied to evaluate these compounds as electrode materials in lithium ion batteries with the discharge capacities of 120 and 257 mAhg−1 in the first thirty cycles, respectively.


2021 ◽  
Vol 13 (4) ◽  
pp. 569-573
Author(s):  
Xian-Feng Li ◽  
Gui-Qiang Diao ◽  
Fang Xie ◽  
Wen-Hua Liao ◽  
Luigi Agostini ◽  
...  

Manganese oxides have been widely studied as anode materials for lithium-ion batteries because they have many advantages such as high theoretical capacity, abundant resources, low price and low environmental tox-icity. In this paper, various manganese oxide materials, i.e., MnO2, Mn3O4, MnO, (FeO)0.331(MnO)0.669 were prepared by facile methods. The above compounds were then characterized through X-ray diffraction spec-troscopy (XRD). The oxidation states of Mn in these compounds were found to be: +4, +3/+2, +2 and +2 each of them corresponding to a different crystal system, respectively: hexagonal, tetragonal cubic, cubic. The electrochemical properties of these four different manganese oxides, used as anode materials, were investigated to find the possible relationship between their valence states, crystal systems and their electrochemical properties. The results show that their electrochemical properties are influenced by their crystal system and cell parameters, while incorporating FeO into MnO has an activation effect on the reversible lithium ion in the batteries.


2020 ◽  
Vol 10 (3) ◽  
pp. 1021
Author(s):  
Yonglei Zheng ◽  
Yikai Li ◽  
He Wang ◽  
Siheng Chen ◽  
Xiangxin Guo ◽  
...  

We report a novel method to fabricate lithium-ion batteries cathodes with the NH4F pretreatment. In this study, NH4F-pretreated Li1.25Ni0.20Fe0.13Co0.33Mn0.33O2 hollow nano-micro hierarchical microspheres were synthesized for use as cathode materials. The X-ray diffraction patterns of NH4F-pretreated Li1.25Ni0.20Co0.33Fe0.13Mn0.33O2 were analyzed with the RIETAN-FP software program, and the results showed that the samples possess a layered α-NaFeO2 structure. The effects of pretreatment with NH4F on the electrochemical performance of the pristine material were evaluated through charge/discharge cycling, the rate performance, and electrochemical impedance spectroscopy (EIS). Pretreatment with NH4F significantly improved the discharge capacities and coulombic efficiencies of Li1.25Ni0.20Co0.33Fe0.13Mn0.33O2 in the first cycle and during subsequent electrochemical cycling. The sample pretreated with an appropriate amount of NH4F (NFCM 90) showed the highest discharge capacity (209.1 mA h g−1) and capacity retention (85.2% for 50 cycles at 0.1 C). The EIS results showed that the resistance of the NFCM 90 sample (76.32 Ω) is lower than that of the pristine one (206.2 Ω).


2020 ◽  
Vol 12 (9) ◽  
pp. 1278-1282
Author(s):  
Jun-Seok Park ◽  
Un-Gi Han ◽  
Gyu-Bong Cho ◽  
Hyo-Jun Ahn ◽  
Ki-Won Kim ◽  
...  

Li[NixCoyMnz]O2 (LiNCM) is one of the candidate cathode material that can replace the currently commercialized LiCoO2 (LCO) cathode material for lithium-ion batteries (LiBs). The morphological feature having primary particle and secondary sphere particle could affect structural stability, tap density and electrochemical performance of LiNCM. In this work, two LiNCM particles without or with the morphological collapse of the secondary particles were prepared by using a co-precipitation-assisted, solid-phase method and ball milling, and its morphological, structural and electrochemical characteristics were evaluated. The results of XRD, and FESEM demonstrated that the as-prepared two LiNCMs have a typical α-NaFeO2 layered structure and the two morphological features of secondary particles needed in this study. The results of electrochemical properties indicated that the LiNCM electrode without collapsed secondary particles have a good stability in cycle performance compared to that with collapse of secondary particles at 0.5, 1.0 and 2 C-rate. The capacity retention of without and with collapsed NCM was 55.8% and 27.3% after 200 cycles at 1 C-rate, respectively.


2013 ◽  
Vol 06 (03) ◽  
pp. 1350029 ◽  
Author(s):  
YUN CHEN ◽  
DUOQING ZENG ◽  
JUANJUAN PENG ◽  
SHIGUANG HU ◽  
ZHAOHUI LI ◽  
...  

Li2FeSiO4/C composites have been successfully prepared by a combination of solution route and high-temperature solid-state reaction processes. The morphology and crystalline structure were characterized using scanning electron microscope (SEM) and X-ray diffraction (XRD). Effects of calcination temperature on the electrochemical properties of Li2FeSiO4/C composite cathodes were investigated by cyclic voltammetry (CV), galvanostatic charge–discharge and electrochemical impedance measurements. The XRD patterns indicate that high-purity Li2FeSiO4 with well-developed crystallinity are obtained above 600°C. The primary particle size was increased by elevating the calcination temperature from 600°C to 750°C. The Li2FeSiO4/C composite synthesized at 650°C delivers the largest initial discharge capacity of 153.2 mAh g-1 with a capacity retention of 93.5% after 30 cycles when tested at a current density of C/16 (1C = 166 mAh g-1) between 1.5 and 4.8 V (vs. Li+/Li ).


2010 ◽  
Vol 156-157 ◽  
pp. 108-112 ◽  
Author(s):  
An Qiang Deng ◽  
Jing Bo Fan ◽  
Ke Nong Qian

La0.8-xPrxMg0.2Ni3.8 (x=0,0.15,0.3,0.4) alloys were prepared by induction melting followed by annealing treatment at 1173K for 24 h. Alloys structure and electrochemical properties of different Pr elecment have been studied systematically by X-ray diffraction(XRD) with the Rietveld methold , scanning electron microscope (SEM)and electrochemical experiments. Alloys structure analyses show that all of the alloys mainly consisted of complex phases such as (La,Pr,Mg)5Ni19 phase(Ce5Co19-type,SG:R-3m), (La,Pr,Mg)5Ni19 phase (Pr5Co19-type, SG:P63/mmc)and (La,Pr)Ni5 phase(CaCu5-type,SG:P6/mmm), Pr eletment was benefited to the formation of Pr5Co19-type phase, The (La,Pr,Mg)5Ni19 phase not only exists in high temperature area but also exists in low temperature area.The activation characteristic and maximum discharge capacity got worse with increasing Pr content,At the same time, The Pr5Co19–type phase and Ce5Co19–type phase all had better electrochemical cyclic stability than the PuNi3-type phase in earth–Mg–Ni-based Hydrogen Storage Alloys.The cyclic stability of alloy electrodes was a closely related to the stacking structures consisting of one Laves-type slab (AB2) and three CaCu5-type slabs (AB5) along the c-axis.


2011 ◽  
Vol 04 (01) ◽  
pp. 61-64 ◽  
Author(s):  
ZHAOHUI LI ◽  
JIAOJUN TANG ◽  
JIE YANG ◽  
CHENG CHENG ◽  
QIZHEN XIAO ◽  
...  

A porous vanadium pentoxide ( V2O5 ) material was prepared through a facile sol-gel route using β-cyclodextrin (β-CD) as template reagent. Its crystal structure and morphology were characterized by X-ray diffraction and scanning electron microscopy, respectively. The electrochemical properties of the as-prepared V2O5 in 1.0 mol l-1 Li2SO4 aqueous electrolyte were investigated by galvanostatic charging/discharging and cyclic voltammetry. The results revealed that the porous V2O5 could deliver the average capacities of 67, 54 and 42 mAh g-1 at the rates of 0.1, 0.5 and 2 C, respectively. The cycling performances of the V2O5/LiMn2O4 cells suggested that the porous V2O5 material could be used as an anode material for aqueous rechargeable lithium-ion batteries.


2011 ◽  
Vol 391-392 ◽  
pp. 1069-1074 ◽  
Author(s):  
Ying Bai ◽  
Feng Wu ◽  
Hua Tong Yang ◽  
Yu Zhong ◽  
Chuan Wu

Spinel LiMn2O4was modified with Y2O3coating by a chemical process. The crystal structures of the as-prepared samples were investigated by X-ray diffraction (XRD). The charge/discharge characteristics of the modified samples were evaluated at different rates between 3.0 and 4.4V. The discharge capacities of 2.0 wt.% Y2O3-coated LiMn2O4are 116 mAh•g−1, 99.7mAh•g−1, 93.3mAh•g−1and 82.9mAh•g−1at 0.1C, 0.5C, 1C and 2C rates (at 20◦C). The cycle abilities improvement of the spinel LiMn2O4coated with Y2O3are demonstrated at elevated temperature (55◦C) and high rates (2C). From the analysis of electrochemical impedance spectroscopy (EIS), the improvement of cycle ability may be attributed to the suppression on the formation of the passivating films and the reduction of Mn dissolution, which result from the surface modification with Y2O3.


2020 ◽  
Vol 20 (3) ◽  
pp. 1740-1748
Author(s):  
Yi-Ni Hu ◽  
Zi-Han Lin ◽  
Fei-Xia Min ◽  
Fei Teng ◽  
Hui-Min Wu ◽  
...  

Pure CuC2O4·xH2O and CuC2O4·xH2O/carbon nanotubes (CNTs) composites are synthesized by a low-temperature hydrothermal process. The structure and morphology of the products are analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TG) and Raman spectrum. The results demonstrate that the as-prepared CuC2O4·xH2O takes on a microsphere-like morphology, all CuC2O4·xH2O/CNTs nanocomposites are constructed by the intertwining of tabular CuC2O4·xH2O nanoparticles (NPs) and CNTs to form a tanglesome net. When evaluated as an anode materials for lithium ion batteries (LIBs), all CuC2O4·xH2O/CNTs electrodes possess higher reversible discharge capacities (more than 1000 mAh g-1) than the pure CuC2O4·xH2O, up to 200th cycle at a current density of 100 mA g-1. The results illustrate that the addition of CNTs can enhance the electrochemical performance of CuC2O4·xH2O. Overall, CuC2O4·xH2O/CNTs composite can be a promising candidate used as a promising anode for LIBs.


2014 ◽  
Vol 1015 ◽  
pp. 438-441
Author(s):  
Ye Jun Zhao ◽  
Zu Ting Pan

The nanoscale TiO2 was synthesized and their electrochemical properties as the anode electrode materials for rechargeable Li-ion batteries were measured. The structure, morphology and electrochemical properties of the nanoscale TiO2 composites synthesized were characterized in detail by X-ray (XRD), Transmission Electron Microscopy (TEM) and electrochemical measurement. The first discharge capacities were 126 mAh/g for the nanoscale TiO2 at the current density of 100 mA/g at ambient temperatures. The specific capacities were stabilized at around 57mAh/g after 20 cycles.


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