scholarly journals Viscosity Analysis of Battery Electrode Slurry

Polymers ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 4033
Author(s):  
Alex Cushing ◽  
Tianyue Zheng ◽  
Kenneth Higa ◽  
Gao Liu
Keyword(s):  
Carbon Black ◽  
Carboxymethyl Cellulose ◽  
Mixing Time ◽  
Active Material ◽  
Polymer Binder ◽  
Conductive Material ◽  
Viscosity Increase ◽  
Internal Structures ◽  
Battery Electrode ◽  
Slurry Viscosity

We report the effects of component ratios and mixing time on electrode slurry viscosity. Three component quantities were varied: active material (graphite), conductive material (carbon black), and polymer binder (carboxymethyl cellulose, CMC). The slurries demonstrated shear-thinning behavior, and suspension properties stabilized after a relatively short mixing duration. However, micrographs of the slurries suggested their internal structures did not stabilize after the same mixing time. Increasing the content of polymer binder CMC caused the greatest viscosity increase compared to that of carbon black and graphite.

Extracting Dispersion from Roughness

2000 ◽  
Vol 661 ◽  
Author(s):  
Claude Tricot
Keyword(s):  
Carbon Black ◽  
Mathematical Analysis ◽  
Mixing Time ◽  
Small Scales ◽  
Scale Roughness

ABSTRACTA mathematical analysis of surfaces may help to understand how the carbon black is dispersed into polymer. Rubber samples are broken out, and the rupture interface is scanned with a prolometer. The roughness is detected at the micron scale. Roughness functions are dened, measuring the average oscillations of the surface. The roughness behaviour is “fractal” for small scales until around 10 microns, then become linear. A roughness ratio is defined, depending both on the scale and on the mixing time. There is evidence to suggest that the roughness ratio does not depend on the polymer, but only on the dispersion of the filler. A dispersion factor is derived, and results are shown on three diserent compounds.

scholarly journals The Effect of Active Material, Conductive Additives, and Binder in a Cathode Composite Electrode on Battery Performance

Energies ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 658 ◽  
Author(s):  
Yoon Lee
Keyword(s):  
Composite Electrode ◽  
Electronic Conductivity ◽  
Active Material ◽  
Transition Metal Ions ◽  
Polymer Binder ◽  
Cell Performance ◽  
Side Reactions ◽  
Interfacial Resistance ◽  
Battery Capacity ◽  
Conductive Additives

The current study investigated the effects of active material, conductive additives, and binder in a composite electrode on battery performance. In addition, the parameters related to cell performance as well as side reactions were integrated in an electrochemical model. In order to predict the cell performance, key parameters including manganese dissolution, electronic conductivity, and resistance were first measured through experiments. Experimental results determined that a higher ratio of polymer binder to conductive additives increased the interfacial resistance, and a higher ratio of conductive additives to polymer binder in the electrode resulted in an increase in dissolved transition metal ions from the LiMn2O4 composite electrode. By performing a degradation simulation with these parameters, battery capacity was predicted with various fractions of constituents in the composite electrode. The present study shows that by using this integrated prediction method, the optimal ratio of constituents for a particular cathode composite electrode can be specified that will maximize battery performance.

scholarly journals Machine Learning Approaches for Designing Mesoscale Structure of Li-Ion Battery Electrodes

Batteries ◽  
2019 ◽  
Vol 5 (3) ◽  
pp. 54 ◽  
Author(s):  
Yoichi Takagishi ◽  
Takumi Yamanaka ◽  
Tatsuya Yamaue
Keyword(s):  
Machine Learning ◽  
Process Parameters ◽  
Volume Fraction ◽  
Specific Resistance ◽  
Active Material ◽  
Li Ion Battery ◽  
Battery Electrode ◽  
Li Ion ◽  
Simulation Results ◽  
Charge Discharge

We have proposed a data-driven approach for designing the mesoscale porous structures of Li-ion battery electrodes, using three-dimensional virtual structures and machine learning techniques. Over 2000 artificial 3D structures, assuming a positive electrode composed of randomly packed spheres as the active material particles, are generated, and the charge/discharge specific resistance has been evaluated using a simplified physico-chemical model. The specific resistance from Li diffusion in the active material particles (diffusion resistance), the transfer specific resistance of Li+ in the electrolyte (electrolyte resistance), and the reaction resistance on the interface between the active material and electrolyte are simulated, based on the mass balance of Li, Ohm’s law, and the linearized Butler–Volmer equation, respectively. Using these simulation results, regression models, using an artificial neural network (ANN), have been created in order to predict the charge/discharge specific resistance from porous structure features. In this study, porosity, active material particle size and volume fraction, pressure in the compaction process, electrolyte conductivity, and binder/additives volume fraction are adopted, as features associated with controllable process parameters for manufacturing the battery electrode. As a result, the predicted electrode specific resistance by the ANN regression model is in good agreement with the simulated values. Furthermore, sensitivity analyses and an optimization of the process parameters have been carried out. Although the proposed approach is based only on the simulation results, it could serve as a reference for the determination of process parameters in battery electrode manufacturing.

scholarly journals Mechanical Integrity of Conductive Carbon-Black-Filled Aqueous Polymer Binder in Composite Electrode for Lithium-Ion Battery

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1460
Author(s):  
Kehua Peng ◽  
Yaolong He ◽  
Hongjiu Hu ◽  
Shufeng Li ◽  
Bao Tao
Keyword(s):  
Carbon Black ◽  
Composite Electrode ◽  
Mechanical Stability ◽  
Critical Role ◽  
Active Material ◽  
Mechanical Damage ◽  
Lithium Ion ◽  
Spherical Particles ◽  
Inorganic Filler ◽  
Composite Electrodes

The mechanical stability of aqueous binder and conductive composites (BCC) is the basis of the long-term service of composite electrodes in advanced secondary batteries. To evaluate the stress evolution of BCC in composite electrodes during electrochemical operation, we established an electrochemical–mechanical model for multilayer spherical particles that consists of an active material and a solid-electrolyte-interface (SEI)-enclosed BCC. The lithium-diffusion-induced stress distribution was studied in detail by coupling the influence of SEI and the viscoelasticity of inorganic-filler-doped polymeric bonding material. It was found that tensile hoop stress plays a critical role in determining whether a composite electrode is damaged or not—and circumferential cracks may primarily initiate in BCC, rather than in other electrode components. Further, the peak tensile stress of BCC is at the interface with SEI and does not occur at full lithiation due to the relaxation nature of polymer composite. Moreover, mechanical damage would be greatly misled if neglecting the existence of SEI. Finally, the structure integrity of the binder and conductive system can be effectively improved by (1) increasing the carbon black content as much as possible in the context of meeting cell capacity requirements—it is greater than 27% and 50% for sodium alginate and the mixtures of carboxy styrene butadiene latex and sodium carboxymethyl cellulose, respectively, for composite graphite anode; (2) reducing the elastic modulus of SEI to less than that of BCC; (3) decreasing the lithiation rate.

Effect of Dispersion on Dynamic Properties of Filler-Loaded Rubbers

1966 ◽  
Vol 39 (2) ◽  
pp. 365-374 ◽  
Author(s):  
A. R. Payne
Keyword(s):  
Carbon Black ◽  
Phase Angle ◽  
Dynamic Viscosity ◽  
Dynamic Modulus ◽  
Dynamic Properties ◽  
Mixing Time

Abstract Increased time of mixing carbon black-rubber vulcanizates reduces dynamic modulus and dynamic viscosity as well as phase angle at moderate amplitudes of oscillation. Changes in dynamic properties with mixing time are shown to be associated with dispersion of carbon black.

scholarly journals A Comparative Evaluation of Sustainable Binders for Environmentally Friendly Carbon-Based Supercapacitors

Nanomaterials ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 46
Author(s):  
Giovanni Landi ◽  
Luca La Notte ◽  
Alessandro Lorenzo Palma ◽  
Andrea Sorrentino ◽  
Maria Grazia Maglione ◽  
...  
Keyword(s):  
Carboxymethyl Cellulose ◽  
Series Resistance ◽  
Active Material ◽  
Environmentally Friendly ◽  
Functional Materials ◽  
Environmental Benefits ◽  
Clear Correlation ◽  
Charge Storage ◽  
Electrochemical Performances ◽  
Carbon Based

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.

scholarly journals Effect of Varying the Ratio of Carbon Black to Vapor-Grown Carbon Fibers in the Separator on the Performance of Li–S Batteries

Nanomaterials ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 436 ◽  
Author(s):  
Hearin Jo ◽  
Jeonghun Oh ◽  
Yong Lee ◽  
Myung-Hyun Ryou
Keyword(s):  
Carbon Black ◽  
Electrochemical Performance ◽  
Carbon Fibers ◽  
Coulombic Efficiency ◽  
Active Material ◽  
High Energy ◽  
High Energy Density ◽  
Lithium Polysulfide ◽  
Carbon Coated ◽  
Coated Separator

Lithium–sulfur (Li–S) batteries are expected to be very useful for next-generation transportation and grid storage because of their high energy density and low cost. However, their low active material utilization and poor cycle life limit their practical application. The use of a carbon-coated separator in these batteries serves to inhibit the migration of the lithium polysulfide intermediate and increases the recyclability. We report the extent to which the electrochemical performance of Li–S battery systems depends on the characteristics of the carbon coating of the separator. Carbon-coated separators containing different ratios of carbon black (Super-P) and vapor-grown carbon fibers (VGCFs) were prepared and evaluated in Li–S batteries. The results showed that larger amounts of Super-P on the carbon-coated separator enhanced the electrochemical performance of Li–S batteries; for instance, the pure Super-P coating exhibited the highest discharge capacity (602.1 mAh g−1 at 150 cycles) with a Coulombic efficiency exceeding 95%. Furthermore, the separators with the pure Super-P coating had a smaller pore structure, and hence, limited polysulfide migration, compared to separators containing Super-P/VGCF mixtures. These results indicate that it is necessary to control the porosity of the porous membrane to control the movement of the lithium polysulfide.

Influence of Morphology and Particle Size of Powdered Rubber on Mill Processing

1975 ◽  
Vol 48 (2) ◽  
pp. 254-262 ◽  
Author(s):  
P. L. Bleyie
Keyword(s):  
Particle Size ◽  
Carbon Black ◽  
Granular Material ◽  
Specific Energy ◽  
Mixing Time ◽  
Considerable Effect ◽  
Area Increase ◽  
Surface Area Increase ◽  
Powdered Rubber ◽  
Carbon Black Dispersion

Abstract The powdered rubber method leads to a considerable shortening of mill mixing time and hence to a reduction of the specific energy required. While the transition from granular material to powder (from above 1 mm to below 1 mm particle size) has considerable effect both on mixing time and on specific energy, the effect of size reduction on specific energy for sizes below 1 mm is substantially smaller than expected from the surface area increase, probably, because a large part of the energy is used for carbon black dispersion. No effect of specific surface on specific energy and mixing time was found.

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