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Full-Text Articles in Chemical Engineering

An Efficient Electrochemical–Thermal Model For A Lithium-Ion Cell By Using The Proper Orthogonal Decomposition Method, Long Cai, Ralph E. White Jan 2010

An Efficient Electrochemical–Thermal Model For A Lithium-Ion Cell By Using The Proper Orthogonal Decomposition Method, Long Cai, Ralph E. White

Faculty Publications

The proper orthogonal decomposition method was applied to develop an efficient, reduced order electrochemical–thermal model for a lithium-ion cell. This model was validated for discharge simulations over a wide range of C rates and various cooling conditions of the cell. The reduced order model agrees well with the COMSOL model, a commercial finite element method solver, and requires times less computation time than the COMSOL model. The model predictions indicate that the discharge time or percent of capacity removed from the cell at an end of discharge voltage of 3.0 V depends on the rate of the discharge and heat …


Short-Time Transient Analysis Of Intercalation Of An Ion Into A Sphere, Sheba Devan, Ralph E. White Jan 2007

Short-Time Transient Analysis Of Intercalation Of An Ion Into A Sphere, Sheba Devan, Ralph E. White

Faculty Publications

A short-time transient analysis is presented for a sinusoidal input potential for a spherical particle. The objective of this work was to extract accurate values of the parameters associated with an intercalation into a spherical particle. These parameters are exchange current density, double-layer capacitance, and diffusion coefficient. The effects of these parameters on the response were examined using a sensitivity analysis, which indicated that optimum frequency values of the input perturbation exist for estimation of these parameters. A procedure is presented to obtain all these parameters using the short-time response. The results show that the short-time analysis is a useful …


Simulation Of The Oxygen Reduction Reaction At An Rde In 0.5 M H2So4 Including An Adsorption Mechanism, Qingbo Dong, Shriram Santhanagopalan, Ralph E. White Jan 2007

Simulation Of The Oxygen Reduction Reaction At An Rde In 0.5 M H2So4 Including An Adsorption Mechanism, Qingbo Dong, Shriram Santhanagopalan, Ralph E. White

Faculty Publications

Oxygen reduction on the surface of a rotating disk electrode (RDE) in 0.5 M H2SO4 is simulated by including mass transfer, adsorption, and charge transfer. A generalized model for the adsorption and reaction of several species is introduced. The oxygen reduction reaction is simulated as a limiting case where oxygen is the only species adsorbed, and oxygen reduction is the only reaction that takes place on the surface of the electrode. The model is based on the Nernst–Planck equations for mass transfer and the Butler–Volmer equation for electrochemical kinetics. The simulated polarization curves capture the change in …


Transient Analysis Of A Porous Electrode, Sheba Devan, Venkat R. Subramanian, Ralph E. White Jan 2005

Transient Analysis Of A Porous Electrode, Sheba Devan, Venkat R. Subramanian, Ralph E. White

Faculty Publications

An analytical expression is presented for the voltage response including the transient voltage for a simple (i.e., no concentration gradients) porous electrode model subject to a sinusoidal input current density. The transient voltage response as a function of the frequency, exchange current density, and double layer capacitance is studied independent of the periodic (steady state) voltage response. The change in the voltage response in the transient region is compared to that of the periodic voltage response with respect to the parameters. The physical properties of the porous electrode can be estimated using the voltage response in the transient …


A Steady-State Impedance Model For A Pemfc Cathode, Qingzhi Guo, Ralph E. White Jan 2004

A Steady-State Impedance Model For A Pemfc Cathode, Qingzhi Guo, Ralph E. White

Faculty Publications

A model for the simulation of the steady-state impedance response of a polymer electrolyte membrane fuel cell (PEMFC) cathode is presented. The catalyst layer of the electrode is assumed to consist of many flooded spherical agglomerate particles surrounded by a small volume fraction of gas pores. Stefan-Maxwell equations are used to describe the multicomponent gas-phase transport occurring in both the gas diffusion layer and the catalyst layer of the electrode. Liquid-phase diffusion of O2 is assumed to take place in the flooded agglomerate particles. Newman’s porous electrode theory is applied to determine over-potential distributions. © 2004 The Electrochemical Society. All …


A Nonisothermal Nickel‐Hydrogen Cell Model, Pauline De Vidts, Javier Delgado, B. Wu, D. M. See, K. Kosanovich, Ralph E. White Jan 1998

A Nonisothermal Nickel‐Hydrogen Cell Model, Pauline De Vidts, Javier Delgado, B. Wu, D. M. See, K. Kosanovich, Ralph E. White

Faculty Publications

No abstract provided.


Governing Equations For Transport In Porous Electrodes, Pauline De Vidts, Ralph E. White Jan 1997

Governing Equations For Transport In Porous Electrodes, Pauline De Vidts, Ralph E. White

Faculty Publications

No abstract provided.


A Multiphase Mathematical Model Of A Nickel/Hydrogen Cell, Pauline De Vidts Jan 1996

A Multiphase Mathematical Model Of A Nickel/Hydrogen Cell, Pauline De Vidts

Faculty Publications

No abstract provided.