Optimizing on the Negative Electrode of Ni/MH Power Battery by Orthogonal Design

2009 ◽  
Vol 610-613 ◽  
pp. 480-487 ◽  
Author(s):  
Xiao Liang Zhong ◽  
Lei Zhu ◽  
Xu Yu Jian ◽  
Hai Jun Yu ◽  
Zhong Wang
Keyword(s):  
Electrochemical Impedance ◽  
Methyl Cellulose ◽  
Negative Electrode ◽  
High Rate ◽  
Styrene Butadiene Rubber ◽  
Orthogonal Experimental Design ◽  
Chemical Compositions ◽  
Butadiene Rubber ◽  
Range Analysis ◽  
Transfer Resistance

In this paper, the influences of different binders (Hydroxypropyl Methyl Cellulose (HPMC), Carboxymethyl Cellulose Sodium (CMC), Polytetrafluoroethylene (PTFE) and Styrene- butadiene Rubber (SBR)) on high-rate discharge performances at low temperature for the negative electrode of Ni/MH battery have been studied by orthogonal experimental design. Electrochemical measurements have been conducted to investigate the capacity, charge-discharge performance, cyclic voltammetry and electrochemical impedance characteristics. The surface morphology and chemical compositions have been investigated by SEM and EDS. Based on the range analysis, the primary and secondary influence factors as well as the optimization results were obtained. From the CV characteristic curves, the oxidization peaks and reduction peaks are not clearly shown, which indicates that the redox reaction does not occur clearly after binders added. The EIS experiments show that the deterioration of the voltage characteristic of the battery is due to drying out of the separator that increases the ohmic resistance (Rs ), and the decay of the discharge capacity is due to the passivity surface that increases the charge-transfer resistance (Rt) of the battery.

Electrochemical Properties of Carbon-Coated NbO2 as a Negative Electrode for Lithium-Ion Batteries

2016 ◽  
Vol 724 ◽  
pp. 87-91 ◽  
Author(s):  
Chang Su Kim ◽  
Yong Hoon Cho ◽  
Kyoung Soo Park ◽  
Soon Ki Jeong ◽  
Yang Soo Kim
Keyword(s):  
Electrochemical Properties ◽  
Lithium Ion Batteries ◽  
Ball Milling ◽  
Carbon Coating ◽  
Electrochemical Impedance ◽  
Active Material ◽  
Negative Electrode ◽  
Lithium Ion ◽  
Transfer Resistance ◽  
Carbon Coated

We investigated the electrochemical properties of carbon-coated niobium dioxide (NbO2) as a negative electrode material for lithium-ion batteries. Carbon-coated NbO2 powders were synthesized by ball-milling using carbon nanotubes as the carbon source. The carbon-coated NbO2 samples were of smaller particle size compared to the pristine NbO2 samples. The carbon layers were coated non-uniformly on the NbO2 surface. The X-ray diffraction patterns confirmed that the inter-layer distances increased after carbon coating by ball-milling. This lead to decreased charge-transfer resistance, confirmed by electrochemical impedance spectroscopy, allowing electrons and lithium-ions to quickly transfer between the active material and electrolyte. Electrochemical performance, including capacity and initial coulombic efficiency, was therefore improved by carbon coating by ball-milling.

scholarly journals From Allergens to Battery Anodes: Nature-Inspired, Pollen Derived Carbon Architectures for Room- and Elevated- Temperature Li-ion Storage

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Jialiang Tang ◽  
Vinodkumar Etacheri ◽  
Vilas G. Pol
Keyword(s):  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Lithium Ion ◽  
Charge Transfer Resistance ◽  
High Rate ◽  
Energy Storage Devices ◽  
Lithium Storage ◽  
Transfer Resistance ◽  
Carbonaceous Particles ◽  
X Ray

Abstract The conversion of allergic pollen grains into carbon microstructures was carried out through a facile, one-step, solid-state pyrolysis process in an inert atmosphere. The as-prepared carbonaceous particles were further air activated at 300 °C and then evaluated as lithium ion battery anodes at room (25 °C) and elevated (50 °C) temperatures. The distinct morphologies of bee pollens and cattail pollens are resembled on the final architecture of produced carbons. Scanning Electron Microscopy images shows that activated bee pollen carbon (ABP) is comprised of spiky, brain-like and tiny spheres; while activated cattail pollen carbon (ACP) resembles deflated spheres. Structural analysis through X-ray diffraction and Raman spectroscopy confirmed their amorphous nature. X-ray photoelectron spectroscopy analysis of ABP and ACP confirmed that both samples contain high levels of oxygen and small amount of nitrogen contents. At C/10 rate, ACP electrode delivered high specific lithium storage reversible capacities (590 mAh/g at 50 °C and 382 mAh/g at 25 °C) and also exhibited excellent high rate capabilities. Through electrochemical impedance spectroscopy studies, improved performance of ACP is attributed to its lower charge transfer resistance than ABP. Current studies demonstrate that morphologically distinct renewable pollens could produce carbon architectures for anode applications in energy storage devices.

Electrochemical Decomposition of Poly(Vinylidene Fluoride) Binder for a Graphite Negative Electrode in Lithium-Ion Batteries

2017 ◽  
Vol 893 ◽  
pp. 127-131 ◽  
Author(s):  
Min Ji Kim ◽  
Chang Hee Lee ◽  
Mun Hui Jo ◽  
Soon Ki Jeong
Keyword(s):  
Lithium Ion Batteries ◽  
Vinylidene Fluoride ◽  
Electrochemical Impedance ◽  
Negative Electrode ◽  
Reduction Process ◽  
Lithium Ion ◽  
Charge Transfer Resistance ◽  
Transfer Resistance ◽  
Electrode Resistance ◽  
Poly Vinylidene Fluoride

To clarify the electrochemical decomposition of poly (vinylidene fluoride) (PVdF) used as a binder for lithium-ion batteries while simultaneously verifying the correlation between electrode resistance and the PVdF content in graphite negative electrodes, in this study, we applied lithium bis (trifluoromethanesulfonyl) imide, which suppresses graphite exfoliation, as a salt. As a result, the electrochemical decomposition of PVdF was observed at a higher potential than that at which the electrolyte was decomposed during the reduction process. Additionally, this study demonstrated (through electrochemical impedance spectroscopy analysis) that electrode resistances such as solid electrolyte interface and charge transfer resistance proportionally increased with the PVdF content.

Experimental study on influence of temperature and C-rate of discharge on performance of in-house fabricated 30Ah Li-ion prismatic cell made with LFP and MCMB

2021 ◽  
pp. 1-20
Author(s):  
T. V. S. L. Satyavani ◽  
Mathiyazhagan Senthilkumar ◽  
G. Dharma Prasad Rao ◽  
Navneet Kumar ◽  
Adapaka Srinivas Kumar
Keyword(s):  
Experimental Study ◽  
Lithium Iron Phosphate ◽  
Electrochemical Impedance ◽  
Temperature Drop ◽  
Lithium Ion ◽  
High Rate ◽  
Transfer Resistance ◽  
Influence Of Temperature ◽  
Different Temperatures ◽  
Li Ion

Abstract Experimental study was carried out to quantify the influence of temperature and different C-rate of discharge on in-house fabricated Lithium-ion (Li-ion) cell. 30Ah Li-ion cell is made of Lithium Iron Phosphate (LFP) cathode and Meso Carbon Micro Beads (MCMB) anode in prismatic configuration. Capability of Li-ion cell is defined by discharge capacity, voltage & power at different C-rate of discharge. Influence of 4 different current rates (C/5, C/2, 1C & 2C) at 5 different temperatures (−20, 0, 20, 40 and 60 °C) were studied. High discharge rate increases current density of cell which affect mass transport at electrode surface and electrolyte. Increased ohmic and concentration polarization at high rate of discharge decrease the original capacity. Average discharge voltage of cell is reduced gradually as operating temperature drop to below 20 °C. Electrochemical Impedance (EI) were measured on Li-ion cell in different frequency domain at different temperatures (−20, 0, 20 and 60 °C). The obtained impedance spectra were examined with an equivalent circuit using Zman software. The ohmic and charge transfer resistance displayed a solid dependence with respect to temperature.

scholarly journals Use of Ashes from Lignite Combustion as Fillers in Rubber Mixtures to Reduce VOC Emissions

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4986
Author(s):  
Miroslawa Prochon ◽  
Dariusz Bieliński ◽  
Paulina Stepaniak ◽  
Magdalena Makowicz ◽  
Dominik Pietrzak ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Brown Coal ◽  
Strength Properties ◽  
Styrene Butadiene Rubber ◽  
Chemical Compositions ◽  
Butadiene Rubber ◽  
Volatile Organic ◽  
The Individual ◽  
Styrene Butadiene

This paper presents the use of ashes from brown coal combustion (BCA) as fillers in rubber mixtures, to reduce the emission of volatile organic compounds. Two types of ash, BCA1 and BCA2, were selected as fillers for styrene–butadiene rubber (SBR). The ashes were produced during the treatment of brown coal at the Bełchatów Power Plant in the years 2017 and 2018. The morphology and chemical composition of the ash were tested. Morphology studies using scanning microscopy showed differences in the grain sizes of the ashes, and EDS analysis showed a difference in their chemical compositions. Vulcanizates with different weight proportions of the individual ashes were produced. Mixtures were made with the addition of 10–30 pts. wt. ashes per 100 g of SBR. The addition of BCA1 ash at 10 and 30 pts. wt. reduced the emission of volatile organic compounds (VOC) while maintaining the good strength properties of the mixtures.

Carbon Nanotube Paper as Anode for Flexible Lithium-Ion Battery

NANO ◽  
2016 ◽  
Vol 11 (11) ◽  
pp. 1650120 ◽  
Author(s):  
Xiaogang Sun ◽  
Zhenhong Liu ◽  
Neng Li ◽  
Xiaoyong Wu ◽  
Yanyan Nie ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Electrochemical Performance ◽  
Lithium Ion Battery ◽  
Electrochemical Impedance ◽  
Negative Electrode ◽  
Lithium Ion ◽  
Charge Transfer Resistance ◽  
Electrochemical Performances ◽  
Multiwalled Carbon ◽  
Transfer Resistance

In this investigation, multiwalled carbon nanotube (MWCNT) paper consists of MWCNTs and cellulose was fabricated by traditional paper-making method. It was applied directly as negative electrode in flexible lithium ion battery to replace ordinary electrode which is combined with anode material and current collector. The electrochemical performances of the as-produced MWCNT paper (AMP) and carbonized MWCNT paper (CMP) were evaluated in this study. The morphology and structure of the MWCNT papers were observed by scanning electron microscopy (SEM). The electrochemical performance of the battery was operated by cell test and electrochemical impedance spectroscopy (EIS) measurement. The charging and discharging results indicated that the CMP behaves with higher capacity than AMP. And the EIS analysis showed that a lower charge transfer resistance can be obtained in the CMP. The excellent electrochemical performance verifies the feasibility of MWCNT papers as a promising candidate for the anode in flexible lithium ion battery.

scholarly journals Facile synthesis and defect optimization of 2D-layered MoS2 on TiO2 heterostructure for industrial effluent, wastewater treatments

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ramalingam Gopal ◽  
Maria Magdalane Chinnapan ◽  
Arjun Kumar Bojarajan ◽  
Naresh Kumar Rotte ◽  
Joice Sophia Ponraj ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Oxygen Vacancies ◽  
Electrochemical Impedance ◽  
Dye Degradation ◽  
Anatase Phase ◽  
Industrial Effluent ◽  
Xrd Analysis ◽  
Charge Transfer Resistance ◽  
Chemical Compositions ◽  
Transfer Resistance

AbstractCurrent research is paying much attention to heterojunction nanostructures. Owing to its versatile characteristics such as stimulating morphology, affluent surface-oxygen-vacancies and chemical compositions for enhanced generation of reactive oxygen species. Herein, we report the hydrothermally synthesized TiO2@MoS2 heterojunction nanostructure for the effective production of photoinduced charge carriers to enhance the photocatalytic capability. XRD analysis illustrated the crystalline size of CTAB capped TiO2, MoS2@TiO2 and L-Cysteine capped MoS2@TiO2 as 12.6, 11.7 and 10.2 nm, respectively. The bandgap of the samples analyzed by UV–Visible spectroscopy are 3.57, 3.66 and 3.94 eV. PL spectra of anatase phase titania shows the peaks present at and above 400 nm are ascribed to the defects in the crystalline structure in the form of oxygen vacancies. HRTEM reveals the existence of hexagonal layered MoS2 formation on the spherical shaped TiO2 nanoparticles at the interface. X-ray photoelectron spectroscopy recommends the chemical interactions between MoS2 and TiO2, specifically, oxygen vacancies. In addition, the electrochemical impedance spectroscopy studies observed that L-MT sample performed low charge transfer resistance (336.7 Ω cm2) that promotes the migration of electrons and interfacial charge separation. The photocatalytic performance is evaluated by quantifying the rate of Congo red dye degradation under visible light irradiation, and the decomposition efficiency was found to be 97%. The electron trapping recombination and plausible photocatalytic mechanism are also explored, and the reported work could be an excellent complement for industrial wastewater treatment.

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