Preparation, structure and electrochemical performances of nanosized cathode active material Ni(OH)

2005 ◽  
Vol 176 (23-24) ◽  
pp. 1909-1914 ◽  
Author(s):  
H ZHOU ◽  
Z ZHOU
2011 ◽  
Vol 236-238 ◽  
pp. 868-871 ◽  
Author(s):  
Meng Liang Tong ◽  
Xuan Yan Liu

Calcium zincate as an active material in Zn/Ni secondary battery has been successfully synthesized by microwave method. The chemical composition of Ca(OH)2·2Zn(OH)2·2H2O was confirmed by X-ray powder diffraction pattern and weight loss in thermogravimetric analysis.The results of cyclic voltammetry and experimental Zn/Ni battery charge–discharge test showed that the material of calcium zincate had excellent electrochemical performances: a high discharging platform of 1.685 V and a good cycleability, discharge capacity would be 70.0% of initial capacity after circulated 120 times.


2010 ◽  
Vol 72 ◽  
pp. 299-304
Author(s):  
Alberto Varzi ◽  
Corina Täubert ◽  
Margret Wohlfahrt-Mehrens ◽  
Martin Kreis ◽  
Walter Schütz

The potential use of multi-walled carbon nanotubes (MWCNTs) produced by chemical vapour deposition (CVD) as a conductive agent for electrodes in Li-ion batteries has been investigated. LiNi0.33Co0.33Mn0.33O2 (NCM) has been chosen as active material for positive electrodes, and a nano-sized TiO2-rutile for the negative electrodes. The electrochemical performances of the electrodes were studied by galvanostatic techniques and especially the influence of the nanotubes on the rate capability and cycling stability has been evaluated. The addition of MWCNTs significantly enhanced the rate performances of both positive and negative electrodes and improved the capacity retention upon cycling. The obtained results demonstrated that the addition of MWCNTs in low amounts to the electrode composition enables an increase in both energy and power density of a Li-ion battery.


2021 ◽  
Author(s):  
Jincy Parayangattil Jyothibasu ◽  
Ruei-Hong Wang ◽  
Kenneth Ong ◽  
Juping Hillary Lin Ong ◽  
Rong-Ho Lee

Abstract This paper reports a simple, cost-effective, and environmentally friendly procedure for the synthesis of cellulose/functionalized carbon nanotube (f-CNT)/Fe2O3 (CCF) composite films and their performance as freestanding negative electrodes in supercapacitors. A facile chemical precipitation process was performed at room temperature within a short reaction time without requiring any of the special processing conditions used in the conventional hydrothermal synthesis, making it the most cost-efficient method for the bulk-scale production of sustainable supercapacitors. The binder-free negative electrode with ultra-high active material loading exhibited outstanding areal (9107.1 mF cm–2) and volumetric (314 F cm–3) capacitances, which were much greater than the values reported previously in the literature for negative electrodes. Moreover, an asymmetric supercapacitor cell featuring cellulose/f-CNT/MnO2 (CCM) and CCF as its positive and negative electrodes, respectively, achieved superior electrochemical performances. Therefore, on account of the economic and environmental superiority of this method and its bulk scalability, this paper provides a simple, eco-friendly, and cost-effective approach for the development of sustainable supercapacitors for practical use.


Nanomaterials ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 46
Author(s):  
Giovanni Landi ◽  
Luca La Notte ◽  
Alessandro Lorenzo Palma ◽  
Andrea Sorrentino ◽  
Maria Grazia Maglione ◽  
...  

Environmentally friendly energy storage devices have been fabricated by using functional materials obtained from completely renewable resources. Gelatin, chitosan, casein, guar gum and carboxymethyl cellulose have been investigated as sustainable and low-cost binders within the electrode active material of water-processable symmetric carbon-based supercapacitors. Such binders are selected from natural-derived materials and industrial by-products to obtain economic and environmental benefits. The electrochemical properties of the devices based on the different binders are compared by using cyclic voltammetry, galvanostatic charge/discharge curves and impedance spectroscopy. The fabricated supercapacitors exhibit series resistance lower than a few ohms and values of the specific capacitance ranged between 30 F/g and 80 F/g. The most performant device can deliver ca. 3.6 Wh/kg of energy at a high power density of 3925 W/kg. Gelatin, casein and carboxymethyl cellulose-based devices have shown device stability up to 1000 cycles. Detailed analysis on the charge storage mechanisms (e.g., involving faradaic and non-faradaic processes) at the electrode/electrolyte interface reveals a pseudocapacitance behavior within the supercapacitors. A clear correlation between the electrochemical performances (e.g., cycle stability, capacitance retention, series resistance value, coulombic efficiency) ageing phenomena and charge storage mechanisms within the porous carbon-based electrode have been discussed.


2014 ◽  
Vol 936 ◽  
pp. 480-485
Author(s):  
Yan Dan Huang ◽  
Ying Bin Lin ◽  
Zhi Gao Huang

LiFePO4/C-Ge electrodes were prepared with vacuum thermal evaporation deposition by depositing Ge films on as-prepared LiFePO4/C electrodes. The effect of Ge film on the electrochemical performances of LiFePO4/C cells was investigated systematically by charge/discharge testing, cyclic voltammograms and AC impedance spectroscopy, respectively. It was found that Ge-film-surface modified LiFePO4/C showed excellent electrochemical performances compared to that of the pristine one in terms of cyclability and rate capability. At 60°C, LiFePO4/C-Ge film exhibited outstanding cyclability with less than 5% capacity fade after 50 cycles while the pristine one suffers 15%. Analysis from the electrochemical measurements showed that the presence of Ge film on the LiFePO4/C electrode would protect active material from HF generated by the decomposition of LiPF6 in the electrolyte and stabilize the surface structure of active material during the charge and discharge cycle. Electrochemical impedance spectroscopy (EIS) results indicated that Ge film mainly reduced the charge transfer resistance Rct of LiFePO4/C electrode, resulting from the suppression of the solid electrolyte interfacial (SEI) film.


2015 ◽  
Vol 1740 ◽  
Author(s):  
Koshin Takemoto ◽  
Hirotoshi Yamada

ABSTRACTElectrochemical performances of a prototype Lithium-Bromine battery (LBB) employing a solid electrolyte was investigated. It showed the discharge capacity of c.a. 147 mAh/(g-LiBr) for the first cycle, which decreased with repeating charge/discharge cycles. The capacity fading was mainly due to increase of the interfacial resistance between an aqueous active material solution and a solid electrolyte. From the results of symmetric cells and structural analysis of the surface of the solid electrolyte immersed in Br2 solutions, it was suggested that a Li+-depletion layer was formed on the surface of the solid electrolyte by contact with bromine.


2018 ◽  
Vol 15 (1) ◽  
pp. 30-40 ◽  
Author(s):  
Dipanwita Majumdar

Ruthenium oxides owing to their high specific capacitance have been widely identified as promising materials for electrochemical charge storage devices. However, high priced ruthenium precursors restrict their commercial usage. Accordingly, numerous explorations investigated the influences on capacitive behavior of ruthenium oxide on blending with varied materials like other metal oxides, activated carbons, conducting polymers, CNTs and functionalized graphene systems as composites. The aim had been to optimize the material cost without compromising with but improving the composite electrochemical performances. The scientific explorations reveal that the overall specific capacitance of composites is a strongly related to the ruthenium oxide (RuO2) present in the system since it is the main electro-active material providing the Faradaic pseudocapacitances besides the electrical double layer contributions from the base carbon component of the composite. Major progress in the theoretical and practical research and development in this particular field has enviced a large number of research articles and technical reports in the recent past. The current investigations focus on utilizing minimum amount of metal in the composite; upholding the synergistic effect from the metal oxide and the support (carbon materials generally) to obtain better electrochemical signatures. Optimization of important factors leading to reduced nanostructure agglomeration, minimum electrostatic resistance and ultrafast proton/electrons diffusion through the hollow porous structures may ultimately result to the theoretically expected specific capacitance. Nonetheless, to the best of knowledge of the author, there is no systematic review available pertaining to recent advancement of the composites of RuO2. Thus, this overview categorically narrates recent progresses on the fabrication, performances and achievements of ruthenium oxide composite as electrode material in energy storage applications which will be beneficial especially to the newcomers in this field of research.


2014 ◽  
Vol 675-677 ◽  
pp. 689-692
Author(s):  
Ji Qing Mao ◽  
Yang Li

Utilization of the waste toner in wasted print cartridge was beneficial to the environmental protection and resource recycling. Fe3O4 has been obtained from the waste toner via magnetic separation and heat-treatment in present study. XRD measurement revealed the recuperated sample has ferriferrous oxide structure without other crystalline impurity. The electrochemical performances of recuperated Fe3O4, as the electrode active material for supercapacitor, was conducted by cyclic voltammetry and charge-discharge process. The results showed that the specific capacitance of Fe3O4 achieved 76.5 F/g under 50 mA/g current density, which possessed typical capacitive behaviors and good cycling stabilities. Based on the preferable electrochemical performances, Fe3O4 recovered from waste toner may be a potential alternative as electrode material for supercapacitor.


2014 ◽  
Vol 953-954 ◽  
pp. 1040-1044
Author(s):  
Yang Li ◽  
Jing Li ◽  
Hua Qing Xie

α-MnO2nanowire was prepared by hydrothermal method. The structure of as-prepared manganese oxide demonstrated tetragonal crystalline in X-ray diffraction pattern. Scan electron microscopy (SEM) and Transmission electron microscopy (TEM) revealed the nanowire morphology of as-prepared α-MnO2. The band gap of α-MnO2was estimated at about 2.06 eV via UV-vis spectrum. As the electrode active material for supercapacitor, the electrochemical specific capacitance of α-MnO2nanowire achieved 156.5 F/g, which possessed typical capacitive behaviors and good cycling stabilities. Based on the preferable electrochemical performances, as-synthesized α-MnO2nanowire may be a potential alternative as electrode material for supercapacitor.


2019 ◽  
Vol 9 (9) ◽  
pp. 1913 ◽  
Author(s):  
Alessandro Dell’Era ◽  
Francesca A. Scaramuzzo ◽  
Marco Stoller ◽  
Carla Lupi ◽  
Marco Rossi ◽  
...  

Sulfur/lithium battery performances are strictly related to the morphology and nanostructure of sulfur particles. In this work, a comparison of the morphological characteristics and electrochemical properties of electrodes based on colloidal sulfur (CS) obtained by means of traditional chemical precipitation from aqueous solution and via spinning disk reactor (SDR) has been performed. In particular, through the SDR technique and by using different fluid dynamic conditions, it was possible to obtain monodisperse and nanometricsulfurparticles with higher electrochemical performances when used as the cathodic active material in lithium batteries. Moreover, a method to produce core–shell nanoparticles with sulfur and titanium dioxide, starting from a colloidal sulfur (S8) solution and produced by SDR, has been performed, obtaining good electrochemical results. In particular, the nanometric sulfur powder produced by the SDR technique showed a capacity higher than CS after 100 cycles, even if the capacity decreased rapidly in both cases. Instead, considering the core–shell S–TiO2 material, the nanostructured electrode allowed a wide use of active material and a reduced capacity decay during cycling. Specifically, the material showed an initial capacity of 1395 mAh/g, i.e., representing 83% of the theoretical value, which decreased during operation up to 450 mAh/g after about 30 cycles. Then, the material capacity remained unchanged and no substantial loss of capacity was recorded up to 100th cycle.


Sign in / Sign up

Export Citation Format

Share Document