Enhanced Electrochemical Performance of CoB Amorphous Alloy through the Addition of Lanthanum

2018 ◽  
Vol 914 ◽  
pp. 102-108
Author(s):  
Wei Zhao ◽  
Yi Lin Liao ◽  
Shu Jun Qiu ◽  
Hai Liang Chu ◽  
Yong Jin Zou ◽  
...  

In order to investigate the effect of lanthanum on the electrochemical properties of CoB amorphous alloy, Co-Lax-B alloys (x = 0, 0.1, 0.5, and 1) were prepared by chemical reduction method. As negative electrodes in alkaline rechargeable batteries, Co-Lax-B alloys exhibit superior electrochemical properties. For Co-La0.1-B alloy, at the discharge current density of 100 mA/g, the initial discharge capacity is 830.6 mAh/g and the discharge capacity has remained around 317.3 mAh/g even after 100 cycles. Moreover, the high-rate discharge ability (HRD) of Co-La0.1-B alloy electrode at the discharge current density of 300 mA/g, 600 mA/g, and 900 mA/g is 98.16%, 95.17%, and 91.86%, respectively. The anodic polarization (AP) and the electrochemical impedance spectra (EIS) measurements indicate that the kinetics of electrochemical performance of the alloys is remarkably improved with the addition of lanthanum.

2017 ◽  
Vol 727 ◽  
pp. 751-755 ◽  
Author(s):  
Wei Zhao ◽  
Yi Lin Liao ◽  
Jian Ling Huang ◽  
Hai Liang Chu ◽  
Shu Jun Qiu ◽  
...  

In order to enhance the electrochemical properties of Co-B alloys used as negative electrode materials of alkaline rechargeable batteries, Co-B alloy was successfully prepared by a chemical reduction method with the assistance of the sonication. The phase structure and the surface morphology of the as-prepared Co-B alloys were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and nitrogen physisorption. Moreover, the electrochemical performance was characterized by galvonostatic charge-discharge tests, electrochemical impedance spectroscopy (EIS) and anodic polarization (AP). Co-B alloy prepared with the assistance of the sonication consists of small particles with a uniform distribution. The electrochemical measurements showed that at a discharge current density of 100 mA/g, the initial discharge capacity was 858.1 mAh/g and the discharge capacity was 322.6 mA/g even at the 100th cycle with the capacity retention of 37.6%.


2013 ◽  
Vol 2013 ◽  
pp. 1-6
Author(s):  
Yuqing Qiao ◽  
Jianyi Xi ◽  
Minshou Zhao ◽  
Guangjie Shao ◽  
Yongchun Luo ◽  
...  

Structure and electrochemical characteristics of La0.96Ce0.04Mg0.15Al0.05Ni2.8hydrogen storage alloy have been investigated. X-ray diffraction analyses reveal that the La0.96Ce0.04Mg0.15Al0.05Ni2.8hydrogen storage alloy consisted of a (La, Mg)Ni3phase with the rhombohedral PuNi3-type structure and a LaNi5phase with the hexagonal CaCu5-type structure. TEM shows that the alloy is multicrystal with a lattice space 0.187 nm. EDS analyse shows that the content of Mg is 3.48% (atom) which coincide well with the designed composition of the electrode alloy. Electrochemical investigations show that the maximum discharge capacity of the alloy electrode is 325 mAh g−1. The alloy electrode has higher discharge capacity within the discharge current density span from 60 mA g−1to 300 mA g−1. Electrochemical impedance spectroscopy measurements indicate that the charge transfer resistanceRTon the alloy electrode surface and the calculated exchange current densityI0are 0.135 Ω and 1298 mA g−1, respectively; the better eletrochemical reaction kinetic of the alloy electrode may be responsible for the better high-rate dischargeability.


2006 ◽  
Vol 320 ◽  
pp. 223-226 ◽  
Author(s):  
Shinya Suzuki ◽  
Seijiro Takahashi ◽  
Keigo Sato ◽  
Masaru Miyayama

High-rate lithium intercalation properties of the Li-Mn-oxide synthesized by the reassembly of MnO2 nanosheets were examined. The colloidal suspension of MnO2 nanosheets was prepared by the exfoliation of proton-exchanged form of layered manganese oxide through the reaction with tetrabutylammonium hydroxide aqueous solution. The results of chemical analysis indicated that a Li-Mn-oxide had a chemical formula of Li0.31MnO2·0.05H2O. The discharge capacity of a Li-Mn-Oxide was 193 mAh/g initially, and decreased gradually during cycling. A Li-Mn-oxide exhibited the discharge capacity of 79 mAh/g at the current density of 2 A/g, and it was 52 % of 151 mAh/g at the current density of 50 mA/g.


Materials ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2025
Author(s):  
Ki Yoon Bae ◽  
Sung Ho Cho ◽  
Byung Hyuk Kim ◽  
Byung Dae Son ◽  
Woo Young Yoon

We developed a novel battery system consisting of a hybrid (LiCoO2 + LiV3O8) cathode in a cell with a hybrid (graphite + Li-metal) anode and compared it with currently used systems. The hybrid cathode was synthesized using various ratios of LiCoO2:LiV3O8, where the 80:20 wt% ratio yielded the best electrochemical performance. The graphite and Li-metal hybrid anode, the composition of which was calculated based on the amount of non-lithiated cathode material (LiV3O8), was used to synthesize a full cell. With the addition of LiV3O8, the discharge capacity of the LiCoO2 + LiV3O8 hybrid cathode increased from 142.03 to 182.88 mA h g−1 (a 28.76% improvement). The energy density of this cathode also increased significantly, from 545.96 to 629.24 W h kg−1 (a 15.21% improvement). The LiCoO2 + LiV3O8 hybrid cathode was characterized through X-ray diffraction analysis, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. Its electrochemical performance was analyzed using a battery-testing system and electrochemical impedance spectroscopy. We expect that optimized synthesis conditions will enable the development of a novel battery system with an increase in energy density and discharge capacity.


NANO ◽  
2019 ◽  
Vol 14 (03) ◽  
pp. 1950028 ◽  
Author(s):  
Liang Yu ◽  
Qingfeng Yi ◽  
Xiaokun Yang ◽  
Xiulin Zhou

Development of a neutral Zn–air battery is of much significance due to the high stability of zinc in a neutral electrolyte. Here, Ni/Co-doped C–N nanotube composites (C–N, Ni/C–N, Co/C–N, and Ni–Co/C–N) as efficient oxygen reduction reaction (ORR) electrocatalysts in a neutral medium have been prepared by direct pyrolysis of Ni/Co salt, dicyandiamide (DCD) and glucose. Among the synthesized catalysts, Ni–Co/C–N presents a high ORR current density of 8.5[Formula: see text]mA[Formula: see text][Formula: see text][Formula: see text]cm[Formula: see text] in a 0.5[Formula: see text]mol[Formula: see text][Formula: see text][Formula: see text]L[Formula: see text] KNO3 solution. The ORR electron transfer number of the catalyst Ni–Co/C–N is 3.8, indicating that O2 is almost completely reduced to H2O. A neutral zinc–air battery utilizing a 0.5[Formula: see text]mol[Formula: see text][Formula: see text][Formula: see text]L[Formula: see text] KNO3 solution has been assembled by using the prepared composite catalyst coated on carbon paper as an air cathode, and Zn plate as an anode. The battery with the cathode catalyst Ni–Co/C–N delivers the open-circuit voltage of 1.13[Formula: see text]V and the maximum power density of 65[Formula: see text]mW[Formula: see text][Formula: see text][Formula: see text]cm[Formula: see text]. The constant discharge current density of 50[Formula: see text]mA[Formula: see text][Formula: see text][Formula: see text]cm[Formula: see text], 100[Formula: see text]mA[Formula: see text][Formula: see text][Formula: see text]cm[Formula: see text] and 150[Formula: see text]mA[Formula: see text][Formula: see text][Formula: see text]cm[Formula: see text] can last 202[Formula: see text]h, 93[Formula: see text]h and 11[Formula: see text]h, respectively. A stable voltage plateau appears at various discharge current densities. The neutral zinc–air battery can be repeatedly discharged after replacing the zinc anode. Results indicate that the synthesized Ni–Co/C–N catalyst is an excellent cathode material applied to a neutral zinc–air battery, showing broad application prospects as a mobile power source.


2012 ◽  
Vol 608-609 ◽  
pp. 917-920
Author(s):  
Yu Zhou ◽  
Yan Ping Fan ◽  
Xian Yun Peng ◽  
Bao Zhong Liu

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.


2019 ◽  
Author(s):  
Panpan Wang ◽  
Yue Du ◽  
Baoyou Zhang ◽  
Yanxin Yao ◽  
Yuchen Xiao ◽  
...  

The <i>β-</i>phase lithium vanadium oxide bronze (<i>β-</i>Li<i><sub>x</sub></i>V<sub>2</sub>O<sub>5</sub>) with high theoretic specific capacity up to 440 mAh g<sup>-1</sup> is considered as promising cathode materials, however, their practical application is hindered by its poor ionic and electronic conductivity, resulting in unsatisfied cyclic stability and rate capability. Herein, we report the surface decoration of <i>β-</i>Li<i><sub>x</sub></i>V<sub>2</sub>O<sub>5</sub> cathode using both reduced oxide graphene and ionic conductor LaPO<sub>4</sub>, which significantly promotes the electronic transfer and Li<sup>+</sup> diffusion rate, respectively. As a result, the rGO/LaPO<sub>4</sub>/Li<i><sub>x</sub></i>V<sub>2</sub>O<sub>5</sub> composite exhibits excellent electrochemical performance in terms of high reversible specific capacity of 275.7 mAh g<sup>-1</sup> with high capacity retention of 84.1% after 100 cycles at a current density of 60 mA g<sup>-1</sup>, and acceptable specific capacity of 170.3 mAh g<sup>-1</sup> at high current density of 400 mA g<sup>-1</sup>. The cycled electrode is also analyzed by electrochemical impedance spectroscopy, <i>ex-situ </i>X-ray diffraction and scanning electron microscope, providing further insights into the improvement of electrochemical performance. Our results provide an effective approach to boost the electrochemical properties of lithium vanadates for practical application in lithium ion batteries.


2014 ◽  
Vol 2 (29) ◽  
pp. 11299-11304 ◽  
Author(s):  
Jin Liang ◽  
Bitao Dong ◽  
Shujiang Ding ◽  
Cuiping Li ◽  
Ben Q. Li ◽  
...  

α-Ni(OH)2 nanosheets@HA hybrid nanostructures exhibit an excellent specific capacitance and cycling stability at a high charge–discharge current density.


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