scholarly journals In Situ Construction of Ag/Ni(OH)2 Composite Electrode by Combining Electroless Deposition Technology with Electrodeposition

Metals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 826
Author(s):  
Sa Lv ◽  
Fan Yang ◽  
Xuefeng Chu ◽  
Huan Wang ◽  
Jia Yang ◽  
...  
Keyword(s):  
Electrochemical Properties ◽  
Electroless Deposition ◽  
Composite Electrode ◽  
Coulombic Efficiency ◽  
Copper Substrate ◽  
High Specific Capacitance ◽  
Growth Strategy ◽  
Equivalent Series Resistance ◽  
Deposition Technology

The Ag/Ni(OH)2 composite electrode has been designed and in situ constructed on a copper substrate by combining electroless deposition technology with electrodeposition. The products can be directly used as a high performance binder free electrode. The synergistic effect between the Ag nanocubes (AgNCs) as backbones and the deposited Ni(OH)2 as the shell can significantly improve the electrochemical properties of the composite electrode. Moreover, this in situ growth strategy forms a strong bonding force of active materials to the substrate, which can improve the cycling performance and lower the equivalent series resistance. The Ag/Ni(OH)2 composite electrode exhibits enhanced electrochemical properties with a high specific capacitance of 3.704 F cm−2, coulombic efficiency of 88.3% and long-term cyclic stability.

PREPARATION AND ELECTROCHEMICAL CAPACITIVE BEHAVIOR OF GRAPHENE BY MICROWAVE ASSISTED THERMAL REDUCTION OF GRAPHITE OXIDE IN HYDRAZINE HYDRATE

NANO ◽  
2014 ◽  
Vol 09 (06) ◽  
pp. 1450066 ◽  
Author(s):  
ZHEN SUN ◽  
QIANGANG FU ◽  
HEJUN LI ◽  
KEZHI LI
Keyword(s):  
Aqueous Solution ◽  
Electrochemical Properties ◽  
Hydrazine Hydrate ◽  
Large Scale ◽  
Electrochemical Impedance ◽  
High Specific Capacitance ◽  
Interlayer Spacing ◽  
Thermal Reduction ◽  
Equivalent Series Resistance ◽  
Selected Area Electron Diffraction

Graphene platelets with a large scale have been synthesized by reduction of graphene oxide (GO) in aqueous solution of hydrazine hydrate under microwave irradiation (MWI). Microstructure of the graphene was characterized by X-ray diffraction (XRD), Raman spectroscopy, atomic force microscopy (AFM) and transmission electron microscopy (TEM) together with the selected area electron diffraction (SAED). The electrochemical properties were evaluated by the analysis of cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) in 1 M Na 2 SO 4 aqueous solution. The results show that the as-prepared materials consist of crumpled, few-layer (~ 3 nm) thick and electronically conductive graphitic sheets. The supercapacitors fabricated using this material possess a low equivalent series resistance (ESR) value ~ 1.6Ω and a high specific capacitance of 285 F ⋅ g-1. In addition, the graphene reduced under a diverse duration of MWI displays a different interlayer spacing, extent of reduction, level of graphitization and specific capacitances. The duration of MWI and the treatment methods strongly affect the microstructure of graphene, and then dominate its electrochemical properties.

scholarly journals Dendrite-Free and Stable Lithium Metal Battery Achieved by a Model of Stepwise Lithium Deposition and Stripping

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Tiancun Liu ◽  
Jinlong Wang ◽  
Yi Xu ◽  
Yifan Zhang ◽  
Yong Wang
Keyword(s):  
Reduction Method ◽  
Coulombic Efficiency ◽  
List Type ◽  
Lithium Metal ◽  
Metal Anode ◽  
In Situ Raman ◽  
Unique Model ◽  
Li Metal Anode ◽  
Pyridinic N

Highlights A facile method is adopted to obtain cucumber-like lithiophilic composite skeleton. Massive lithiophilic sites in cucumber-like lithiophilic composite skeleton can promote and guide uniform Li depositions. A unique model of stepwise Li deposition and stripping is determined. Abstract The uncontrolled formation of lithium (Li) dendrites and the unnecessary consumption of electrolyte during the Li plating/stripping process have been major obstacles in developing safe and stable Li metal batteries. Herein, we report a cucumber-like lithiophilic composite skeleton (CLCS) fabricated through a facile oxidation-immersion-reduction method. The stepwise Li deposition and stripping, determined using in situ Raman spectra during the galvanostatic Li charging/discharging process, promote the formation of a dendrite-free Li metal anode. Furthermore, numerous pyridinic N, pyrrolic N, and CuxN sites with excellent lithiophilicity work synergistically to distribute Li ions and suppress the formation of Li dendrites. Owing to these advantages, cells based on CLCS exhibit a high Coulombic efficiency of 97.3% for 700 cycles and an improved lifespan of 2000 h for symmetric cells. The full cells assembled with LiFePO4 (LFP), SeS2 cathodes and CLCS@Li anodes demonstrate high capacities of 110.1 mAh g−1 after 600 cycles at 0.2 A g−1 in CLCS@Li|LFP and 491.8 mAh g−1 after 500 cycles at 1 A g−1 in CLCS@Li|SeS2. The unique design of CLCS may accelerate the application of Li metal anodes in commercial Li metal batteries.

Probing Structure Modification of Palladium Nanomaterials during Chemical Synthesis by using In Situ X-ray Diffraction: Electrochemical Properties

2015 ◽  
Vol 2 (4) ◽  
pp. 592-599 ◽  
Author(s):  
Yaovi Holade ◽  
Teko W. Napporn ◽  
Claudia Morais ◽  
Karine Servat ◽  
K. Boniface Kokoh
Keyword(s):  
Chemical Synthesis ◽  
Electrochemical Properties ◽  
Structure Modification ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals Electrochemical Solvent Cointercalation into Graphite in Propylene Carbonate-Based Electrolytes: A Chronopotentiometric Characterization

2018 ◽  
Vol 2018 ◽  
pp. 1-5 ◽  
Author(s):  
Hee-Youb Song ◽  
Soon-Ki Jeong
Keyword(s):  
Propylene Carbonate ◽  
Redox Reactions ◽  
High Current Density ◽  
Coulombic Efficiency ◽  
Pyrolytic Graphite ◽  
Lithium Ion ◽  
In Situ Raman Spectroscopy ◽  
Force Microscopy ◽  
Atomic Force

Interfacial reactions strongly influence the performance of lithium-ion batteries, with the main interfacial reaction between graphite and propylene carbonate- (PC-) based electrolytes corresponding to solvent cointercalation. Herein, the redox reactions of solvated lithium ions occurring at the graphite interface in 1 M·LiClO4/PC were probed by chronopotentiometry, in situ atomic force microscopy (AFM), and in situ Raman spectroscopy. The obtained results revealed that high coulombic efficiency (97.5%) can be achieved at high current density, additionally showing the strong influence of charge capacity on the above redox reactions. Moreover, AFM imaging indicated the occurrence of solvent cointercalation during the first reduction, as reflected by the presence of hills and blisters on the basal plane of highly oriented pyrolytic graphite subjected to the above process.

In Situ Electrochemical Study of Copper Nanoparticles Stabilized with Food Grade Gelatin

2016 ◽  
Vol 705 ◽  
pp. 163-167 ◽  
Author(s):  
Ellaine M. Datu ◽  
Mary Donnabelle L. Balela
Keyword(s):  
Electroless Deposition ◽  
Reduction Rate ◽  
In Situ Monitoring ◽  
Mixed Potential ◽  
Cu Nanoparticles ◽  
Environment Friendly ◽  
Food Grade ◽  
Alternative Material ◽  
Kinetics Of

Commercially available conductive inks are typically made up of precious metal nanoparticles, such as gold (Au) and silver (Ag). Thus, cheaper metals like copper (Cu) are currently being explored as alternative material. Though Cu has a comparable conductivity to that of Ag, they tend to oxidize easily when exposed to air and water, which could limit their application. In this work, oxidation-stable Cu nanoparticles with mean diameter as small as 57 nm were prepared by simple electroless deposition in water. Food-grade gelatin was used as stabilizer, which makes the process more economical and environment-friendly. In situ monitoring of mixed potential was carried out during synthesis to understand the kinetics of the reaction. The mixed potential of the solution shifted negatively as the amount of gelatin was increased. This suggests faster reduction rate.

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