Microstructures and Electrochemical Properties of La0.7Ce0.3Ni3.7Co0.7-xAl0.2Mn0.4(Fe0.43B0.57)x (x = 0-0.4) Hydrogen Storage Alloys

2012 ◽  
Vol 608-609 ◽  
pp. 917-920
Author(s):  
Yu Zhou ◽  
Yan Ping Fan ◽  
Xian Yun Peng ◽  
Bao Zhong Liu
Keyword(s):  
Hydrogen Storage ◽  
Electrochemical Properties ◽  
Discharge Capacity ◽  
Secondary Phase ◽  
Cycling Stability ◽  
High Rate ◽  
X Ray Diffraction ◽  
Hydrogen Storage Alloys ◽  
X Ray ◽  
The Matrix

X-ray diffraction results indicate that pristine alloy has a single LaNi5 phase and the alloys containing Fe0.43B0.57 consist of the matrix LaNi5 phase and the La3Ni13B2 secondary phase. The abundance of La3Ni13B2 phase increases with increasing x value. Maximum discharge capacity of the alloy electrodes monotonically decreases from 336.1 mAh/g (x = 0) to 281.2 mAh/g (x = 0.4). High-rate dischargeability of the alloy electrodes first increases with increasing x from 0 to 0.20, and then decreases when x increases to 0.4. Cycling stability decreases with increasing x from 0 to 0.4.

Effect of Annealing Treatment on Structure and Electrochemical Properties of LaNi4.5Co0.25Al0.25 Alloy with Low Co Content

2013 ◽  
Vol 788 ◽  
pp. 141-146
Author(s):  
Feng Wang ◽  
Huai Ying Zhou ◽  
Jiang Wang ◽  
Zhong Min Wang ◽  
Huai Gang Zhang ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Electrochemical Properties ◽  
Discharge Capacity ◽  
Annealing Treatment ◽  
Electrochemical Measurement ◽  
X Ray Diffraction ◽  
Capacity Retention ◽  
X Ray ◽  
The Matrix ◽  
Suitable Treatment

The effect of annealing treatment on the structure and electrochemical properties of LaNi4.5Co0.25Al0.25 alloy was studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrochemical measurement. XRD results show that the matrix phases are still LaNi5 (hexagonal CaCu5 type structure) but the intensity peaks become sharper after heat treatment. Electrochemical experiments at 301 K indicate that annealing treatment can significantly improve the discharge capacity and cyclic stability of LaNi4.5Co0.25Al0.25 alloy at suitable treatment condition. The alloy has the best discharge capacity (324.4 mAg-1) due to its composition homogenization after heat treatment at 1373 K/8 h, while the best capacity retention is about 80.12 % because of lower expansion rate and better anti-pulverization ability after heat treatment at 1273 K/8 h.

Crystallographic and Electrochemical Performances of La0.73Ce0.27Ni3.25+xMn0.35Al0.15Cu0.75Fe0.25 (x = 0-0.75) Hydrogen Storage Alloys

2013 ◽  
Vol 772 ◽  
pp. 98-102
Author(s):  
Yu Zhou ◽  
Xian Yun Peng ◽  
Li Qiang Ji ◽  
Yan Ping Fan
Keyword(s):  
Hydrogen Storage ◽  
Electrochemical Properties ◽  
Linear Relationship ◽  
Cell Volume ◽  
Discharge Capacity ◽  
Lattice Parameter ◽  
Hexagonal Structure ◽  
High Rate ◽  
Electrochemical Performances ◽  
Hydrogen Storage Alloys

Microstructuresand electrochemical properties of La0.73Ce0.27Ni3.25+xMn0.35Al0.15Cu0.75Fe0.25 alloys are investigated. XRD results indicate that all alloys are identified with LaNi5 phase with CaCu5 type hexagonal structure, and lattice parameter a, c and cell volume V decrease with increasing x value. Maximum discharge capacity first increases from 286.4 mAh/g (x = 0) to 313.2 mAh/g (x = 0.25), and then decreases to 308.9 mAh/g (x = 0.75). High-rate dischargeability of the alloy electrodes increases when x increases from 0 to 0.75. HRD1200 increases with the increase in the I0 and D, and shows a linear relationship with the I0 and D.

Microstructure and Electrochemical Properties of La0.7Mg0.3(Ni1-xCox)3.5(x=0.0-0.2) Type Hydrogen Storage Alloy

2013 ◽  
Vol 365-366 ◽  
pp. 1198-1202
Author(s):  
Xiao Yun Zhao
Keyword(s):  
Hydrogen Storage ◽  
Electrochemical Properties ◽  
Discharge Capacity ◽  
Type Structure ◽  
Hydrogen Storage Alloy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electrochemical Discharge

La0.7Mg0.3(Ni1-xCox)3.5 (x=0.0-0.2) type hydrogen storage alloy was prepared. In order to optimizing the content of Co it was studied effects that Co replaced Ni on the structure and electrochemical properties of La0.7Mg0.3(Ni1-xCox)3.5(x=0.0-0.2) type hydrogen storage alloy X-ray diffraction (XRD) analyses showed that the alloys were composed of the LaNi5 phase with the CaCu5-type structure and the (La,Mg)2Ni7 phase with the Ce2Ni7-type structure. The maximum electrochemical discharge capacity increases with the increase of Co content. Moreover, the cycle stabilities of La0.7Mg0.3(Ni1-xCox)3.5 was improved remarkably by small quantity replacement Ni by Co, after 250 times, the discharge capacity was increased from 30% (x=0.0) to 65% (x=0.20).

scholarly journals Structural and Electrochemical Properties of Lithium Nickel Oxide Thin Films

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Gyu-bong Cho ◽  
Tae-hoon Kwon ◽  
Tae-hyun Nam ◽  
Sun-chul Huh ◽  
Byeong-keun Choi ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Electrochemical Properties ◽  
Discharge Capacity ◽  
Oxygen Deficiency ◽  
Oxide Phase ◽  
Rf Magnetron Sputtering ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lithium Nickel Oxide

LiNiO2thin films were fabricated by RF magnetron sputtering. The microstructure of the films was determined by X-ray diffraction and field-emission scanning electron microscopy. The electrochemical properties were investigated with a battery cycler using coin-type half-cells. The LiNiO2thin films annealed below 500°C had the surface carbonate. The results suggest that surface carbonate interrupted the Li intercalation and deintercalation during charge/discharge. Although the annealing process enhanced the crystallization of LiNiO2, the capacity did not increase. When the annealing temperature was increased to 600°C, the FeCrNiO4oxide phase was generated and the discharge capacity decreased due to an oxygen deficiency in the LiNiO2thin film. The ZrO2-coated LiNiO2thin film provided an improved discharge capacity compared to bare LiNiO2thin film suggesting that the improved electrochemical characteristic may be attributed to the inhibition of surface carbonate by ZrO2coating layer.

High Active Hydrogen Storage Alloy Mg2NiH4 and Mg2Ni Synthesized at Temperatures Lower than 733 K

2005 ◽  
Vol 488-489 ◽  
pp. 901-904 ◽  
Author(s):  
Xiao Feng Liu ◽  
Li Quan Li
Keyword(s):  
Low Temperature ◽  
Hydrogen Storage ◽  
Hydrogen Storage Alloy ◽  
Activation Process ◽  
Active Hydrogen ◽  
X Ray Diffraction ◽  
Hydrogen Storage Alloys ◽  
X Ray ◽  
Production Of Hydrogen ◽  
Temperature And Pressure

Hydrogen storage alloys Mg2Ni and Mg2NiH4 were synthesized at below 733 K by the process HCS. The product was examined by X-Ray diffraction and hydriding / dehydriding dynamics was tested. The result reveals that (1) High pure products of Mg2Ni and Mg2NiH4 can be obtained even at temperature 673 K and 0.1 MPa argon and 1.0 MPa hydrogen, respectively; (2) Both products are high active absorbing hydrogen > 3.2 mass % at 603 K without activation process. The result is very attractive due to the low temperature and pressure for the production of hydrogen storage alloys.

scholarly journals In situ X-ray Diffraction Investigation of Hydrogen Storage Alloys During Charge and Discharge

2016 ◽  
Vol 1 (4) ◽  
pp. 710-714
Author(s):  
Waldemir J. Paschoalino ◽  
Stephen J. Thompson ◽  
David Inwood ◽  
Claire Murray ◽  
Chiu C. Tang ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
X Ray Diffraction ◽  
Hydrogen Storage Alloys ◽  
X Ray

Phase Structure of (La,Mg,Nd)5Ni19 Hydrogen Storage Alloy

2013 ◽  
Vol 455 ◽  
pp. 66-70
Author(s):  
Qiang He ◽  
Yong Quan Guo ◽  
Zhen Zhen Zheng
Keyword(s):  
Hydrogen Storage ◽  
Structural Unit ◽  
Type Structure ◽  
Hydrogen Storage Alloy ◽  
X Ray Diffraction ◽  
Hydrogen Storage Alloys ◽  
Lattice Match ◽  
X Ray ◽  
Good Lattice ◽  
Three Phases

The crystal structure of (La,Mg,Nd)5Ni19alloy has been investigated using powder x-ray diffraction. A Rietveld refinement is used to determine the phase structures for tying to find out the correlations of lattices among the phases in this hydrogen storage alloy. The results show that the alloy consists of three phases, which correspond to (La,Mg)3Nd2Ni19with a Pr5Co19-type structure, La (Mg,Nd)Ni7phase with a Ce2Ni7-type structure and (La,Mg)3Nd2Ni19with a Ce5Co19-type structure. Mg and Nd substitute for La atom at the 4f position for Pr5Co19-type and Ce2Ni7-type structures and the 6c position for Ce5Co19-type structure, respectively. It induces a good lattice match along the a-axisand b-axis among the three phases. The three kinds of structures might form a rod-like shape structural unit by stacking along the c-axis. This phase constitution seems to be beneficial for the cyclic stability of the hydrogen storage alloys.

Effect of Milling Time on Microstructures and Electrochemical Properties of AB3.5-Type La-Mg-Ni-Co-Al Hydrogen Storage Alloys

2019 ◽  
Vol 288 ◽  
pp. 9-16
Author(s):  
Xiao Tian ◽  
Wei Wei ◽  
Jing Yan ◽  
Xin Zhang ◽  
Zhan Quan Yao ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Electrochemical Properties ◽  
Discharge Capacity ◽  
Milling Time ◽  
Electrochemical Measurements ◽  
Cyclic Stability ◽  
Hydrogen Storage Alloys ◽  
Discharge Potential ◽  
Aggregation Phenomena ◽  
Better Than

La0.70Mg0.30Ni2.45Co0.75Al0.30 alloys were synthesized by milling and blending of the La0.70Ni2.45Co0.75Al0.30 pre-alloy prepared by melting and elemental Mg, followed by annealing. The effects of milling time on the microstructures and electrochemical properties of the La0.70Mg0.30Ni2.45Co0.75Al0.30 hydrogen storage alloys were investigated. The structure, microstructure and electrochemical properties of the alloys were investigated by XRD, SEM and electrochemical measurements. The results showed that a noticeable (La,Mg)2Ni7 phase can be observed in the alloy milled for 2 h. Moreover, the distribution of the Mg element in the alloy milled for 15 h presents some aggregation phenomena. The La0.70Mg0.30Ni2.45Co0.75Al0.30 alloy milled for 2 h exhibits the best maximum discharge capacity (313.5 mAh/g) and discharge potential characteristic. The cyclic stability of the as-cast La0.70Ni2.45Co0.75Al0.30 alloy is better than that of the milled La0.70Mg0.30Ni2.45Co0.75Al0.30 alloy.

The Phase Structure and Electrochemical Properties of La4MgNi17M2(M=Ni,Co,Mn) Hydrogen Storage Alloys

2014 ◽  
Vol 875-877 ◽  
pp. 282-287
Author(s):  
Fan Song Wei ◽  
Fan Na Wei ◽  
Huan Huan Lu ◽  
Hong Fu Xiang
Keyword(s):  
Hydrogen Storage ◽  
Electrochemical Properties ◽  
Phase Structure ◽  
Storage Capacity ◽  
Electrochemical Measurement ◽  
Xrd Analysis ◽  
High Rate ◽  
Cyclic Stability ◽  
Hydrogen Storage Alloys ◽  
Hydrogen Storage Capacity

The phase structure and electrochemical properties of La4MgNi17M2(M=Ni,Co,Mn) alloys were investigated in detail. The XRD analysis revealed that the main phases in the alloys are LaNi5 and La4MgNi19 phases (Ce5Co19+Pr5Co19 structure). When the Ni element in the alloy was substituted by Mn or Co, the abundant of La4MgNi19 phase increased, and especially in the La4MgNi17Mn2 alloy, that increased to 70.7%. The electrochemical measurement showed that the activation of La4MgNi17M2(M=Ni,Co,Mn) alloy electrodes were improved, and it only needed 1-2 cycles.what’s more, with the elements substitution for Ni ,the maximum discharge capacity gradually increased to 386.10 mA·h/g (Co) and 375.18 mA·h/g (Mn), but high-rate dischargeability (HRD) decreased somewhat (Co, HRD900=86.2%). It is found that the HRD was mainly controlled by the electrocatalytic activity on the alloy electrode surface, and the decline of cyclic stability was due to the appearance of A5B19 type phase with larger hydrogen storage capacity, which lead to bigger volume expansion or intercrystalline stress, then easier pulverization during charging/discharging. In addition, the cyclic stability (S100) was improved with Co substitution, and worsened with Mn substitution, because Mn element was easily corroded and Co improved the ability of Corrosion resistance.

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