The Effect of Particle Size on the Discharge Performance of a Nickel‐Metal Hydride Cell

Heikonen, J.; Ploehn, Harry J.; White, Ralph E.

doi:10.1149/1.1838565

Cited by 17 publications

(5 citation statements)

References 8 publications

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“…Darling and Newman 15 also modeled a porous intercalation electrode with two characteristic particle sizes and found that PSD had an even more pronounced influence on the open-circuit behavior. Heikonen et al 16 considered the effects of PSD on the discharge behavior of a nickel-metal hydride cell. Card et al 17 developed a model for an activated-carbon, packed-bed electrochemical reactor that considered the effects of both micropores and macropores.…”

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confidence: 99%

Modeling the Effects of Electrode Composition and Pore Structure on the Performance of Electrochemical Capacitors

Cheng

Popov

Ploehn

2002

J. Electrochem. Soc.

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This work presents a mathematical model for charge/discharge of electrochemical capacitors that explicitly accounts for particlepacking effects in a composite electrochemical capacitor consisting of hydrous RuO 2 nanoparticles dispersed within porous activated carbon. The model is also used to investigate the effect of nonuniform distributions of salt in the electrolyte phase of the electrode in the context of dilute solution theory. We use the model to compare the performance of capacitors with electrodes made from different activated carbons and to investigate the effects of varying carbon content and discharge current density. Even at low discharge current density, concentration polarization in the electrodes results in underutilization of the electrodes' charge-storage capability, and thus decreased performance. Among various types of activated carbons, those with large micropore surface areas and low meso-and macropore surface areas are preferred because they give high double-layer capacitance and favor efficient packing of RuO 2 nanoparticles, thus maximizing faradaic pseudocapacitance. Increasing the electrode carbon content decreases the delivered charge and energy density, but the reductions are not severe at moderate carbon content and high discharge current. This suggests the possibility of optimizing the carbon content to minimize cost while achieving acceptable discharge performance. Electrochemical capacitors are urgently needed as components in many advanced power systems requiring high power density, high energy density, and high cycleability.1-6 Energy storage mechanisms in an electrochemical capacitor include separation of charge at the interface between a solid electrode and a liquid electrolyte, leading to double-layer ͑DL͒ capacitance, and faradaic redox reactions occurring at or near a solid electrode surface, known as pseudocapacitance. Charge storage in DL capacitance is essentially electrostatic in nature, and so DL charge/discharge processes are usually highly reversible. Pseudocapacitance, originating from faradaic redox reactions of oxides like RuO 2 , IrO 2 , or Co 3 O 4 at or near the electrode surface, involves interfacial reaction as well as mass transfer of ionic charge across the double layer. 6 Capacitors employing both DL and pseudocapacitance generally perform better than those featuring just one kind of capacitance. Activated carbon has been frequently used because its porous structure and large internal surface area result in electrodes with high specific energy and specific power densities. 6 The pore structure of activated carbon is a significant element in determining electrochemical capacitor performance. Shi 7 argued that pores of different sizes ͑micro-, meso-, and macropores͒ play different roles in contributing to DL capacitance. Macropores make a small contribution to the total specific surface area and thus contribute little to the DL capacitance. At the other extreme, micropores are responsible for most of the specific surface area, but the smallest pores may not...

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confidence: 99%

Modeling the Effects of Electrode Composition and Pore Structure on the Performance of Electrochemical Capacitors

Cheng

Popov

Ploehn

2002

J. Electrochem. Soc.

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“…The smaller is the particle, the higher the discharge capacity is obtained. This is due to the fact that smaller particles have shorter di usion length [18] and larger speciÿc surface area, which results in smaller current density on the particle surface. During the charge process, the smaller current density will increase the charge e ciency by decreasing hydrogen atom recombination on the surface to form hydrogen gas.…”

Section: Resultsmentioning

confidence: 99%

Electrochemical performance of ball-milled Ti?V-based electrode alloy

Zhang

Xia

et al. 2005

International Journal of Hydrogen Energy

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“…where β is the damage sharpness and slope controlling parameter and κ 0 is the initial damage threshold; see Figure 1. Knowing the damage evolution law and following Equation 27, the rate forms of the tangent , [33] where…”

Section: Non-local Damage Formulationmentioning

confidence: 99%

“…30,31 For example in LSLIBs, numerical studies on the effect of electrode particle size on the performance of the battery showed that, for example, an electrode layer with non-uniform, different sized particles has a higher capacity than electrodes with uniform single sized particles. 32,33 Also under damage evolution, an electrode layer with non-uniform different sized particles demonstrates better performance and reduces the capacity fade caused by the damage evolution. 34,35 At low discharge rates, large particles increase the capacity, however, the capacity decreases more quickly when the discharge rate increases.…”

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Numerical Modeling of Damage Evolution Phenomenon in Solid-State Lithium-Ion Batteries

Behrou

Maute

2017

J. Electrochem. Soc.

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This paper presents a finite element methodology for numerical modeling the evolution of damage in Solid-State Lithium-Ion Batteries (SSLIBs). This process is dominated by the interaction of electrochemical and mechanical phenomena in the electrode, solid-state electrolyte, and electrode/electrolyte interface. These phenomena depend on the transport process of species/ions, mechanical deformations, electrostatics, and electrochemical reactions. Damage evolution in the electrode active material, caused by diffusion-induced stresses, is described by a non-local damage model. To model the influence of the damage evolution on the ion/species transport and the electrochemical performance of the battery, the diffusivity of the electrode is coupled with the damage evolution. The impact of damage evolution on the electrochemical and mechanical responses of the SSLIB is studied by numerical examples. The results indicate that the evolution of the damage during a cyclic charge/discharge process diminishes the electrochemical and mechanical performances of the battery by reducing the transport properties, decreasing the capacity, and lessening the strength of the active material. The numerical studies further suggest that electrode particles with large aspect ratios have better performance and decrease the damage-induced capacity fade.

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The Effect of Particle Size on the Discharge Performance of a Nickel‐Metal Hydride Cell

Cited by 17 publications

References 8 publications

Modeling the Effects of Electrode Composition and Pore Structure on the Performance of Electrochemical Capacitors

Modeling the Effects of Electrode Composition and Pore Structure on the Performance of Electrochemical Capacitors

Electrochemical performance of ball-milled Ti?V-based electrode alloy

Numerical Modeling of Damage Evolution Phenomenon in Solid-State Lithium-Ion Batteries

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