Enhanced cycling stability and high rate dischargeability of (La,Mg) 2 Ni 7 -type hydrogen storage alloys with (La,Mg) 5 Ni 19 minor phase

2015 ◽  
Vol 287 ◽  
pp. 237-246 ◽  
Author(s):  
Jingjing Liu ◽  
Shumin Han ◽  
Da Han ◽  
Yuan Li ◽  
Shuqin Yang ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Cycling Stability ◽  
High Rate ◽  
Minor Phase ◽  
Hydrogen Storage Alloys

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.

Effects of Al on Cycling Stability of a New Rare-Earth Mg-Based Hydrogen Storage Alloy

2005 ◽  
Vol 475-479 ◽  
pp. 2457-2462 ◽  
Author(s):  
Y.F. Liu ◽  
H.G. Pan ◽  
Rui Li ◽  
Y.Q. Lei
Keyword(s):  
Rare Earth ◽  
Oxide Film ◽  
Hydrogen Storage ◽  
Cycling Stability ◽  
Type Structure ◽  
High Rate ◽  
Kinetic Properties ◽  
Hydrogen Storage Alloys ◽  
Al Content ◽  
Discharge Capacities

In order to improve the cycling stability of a new rare-earth Mg-based hydrogen storage alloys, La0.7Mg0.3Ni2.65-xMn0.1Co0.75Alx (x=0.0-0.4) alloys were prepared to investigate the structure and electrochemical properties of these alloys. XRD and Rietveld analyses reveal that the alloys consist of a (La,Mg)Ni3 phase with rhombohedral PuNi3-type structure and a LaNi5 phase with hexagonal CaCu5-type structure. Electrochemical studies on these alloys indicate that their maximum discharge capacities were decreased from 400.7 mAh/g (x=0.0) to 335.6 mAh/g (x=0.4). However, the cycling stability of the alloy electrodes was significantly improved after Ni was partially replaced by Al. After 100 charge/discharge cycles, the discharge capacity retention was increased from 32.0% (x=0.0) to 73.8 % (x=0.3), which can be attributed to the formation of a dense oxide film on the alloy surface. Moreover, the high rate dischargeability measurements indicate that the electrochemical kinetic properties were deteriorated with increasing Al content owing to the presence of a dense oxide film of Al.

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.

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.

A new strategy for enhancing the cycling stability of superlattice hydrogen storage alloys

2021 ◽  
pp. 129395
Author(s):  
Jingjing Liu ◽  
Xiangyu Chen ◽  
Jie Xu ◽  
Shuai Zhu ◽  
Honghui Cheng ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Cycling Stability ◽  
Hydrogen Storage Alloys ◽  
New Strategy

Investigation on Structure and Electrochemical Properties of MgNi+x%B (x=0,2,5,10) Hydrogen Storage Alloys

2011 ◽  
Vol 311-313 ◽  
pp. 1375-1383
Author(s):  
Zi Li Liu ◽  
Xin Bo Liu ◽  
Xin Chun Yan ◽  
Gui Bin Zhou
Keyword(s):  
Hydrogen Storage ◽  
Discharge Capacity ◽  
Current Density ◽  
Retention Rate ◽  
Exchange Current ◽  
Exchange Current Density ◽  
High Rate ◽  
Boron Addition ◽  
Hydrogen Storage Alloys ◽  
Atom Ratio

Amorphous MgNi+x%B(x=0,2,5,10) hydrogen storage alloys have been prepared by mechanical alloying (MA) and tested as hydrogen storage electrodes. The addition of boron can promote the MgNi alloy to form amorphous phase, increase the atom ratio of Ni/Mg at the alloy powders’ surface, and improve the thermal stability of MgNi alloy. The discharge capacity, the high rate dischargeability (HRD) and the exchange current density of the alloy electrodes all increased first, and then decreased with increasing the addition of boron. The maximum discharge capacity, the HRD400 and the exchange current density of the alloy with 5%B were 411.6mAh/g, 58.3% and 293.5mA/g respectively, which were 21.8%, 40.0% and 351.5% higher respectively, comparing with that of no boron addition. The electrochemical cycle stability of the alloy electrodes increased with increasing boron additions, and compared with no boron addition, the cycle capacity retention rate S20 of the alloy with 10%B increased 64.2%.

A new strategy to improve the high-rate performance of hydrogen storage alloys with MoS2 nanosheets

2016 ◽  
Vol 333 ◽  
pp. 17-23 ◽  
Author(s):  
L.X. Chen ◽  
Y.F. Zhu ◽  
C.C. Yang ◽  
Z.W. Chen ◽  
D.M. Zhang ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
High Rate ◽  
Rate Performance ◽  
Mos2 Nanosheets ◽  
Hydrogen Storage Alloys ◽  
New Strategy ◽  
High Rate Performance
Sign in / Sign up

Export Citation Format

Share Document