Electrochemical model of local corrosion at the tip of a loaded crack

1995 ◽  
Vol 30 (1) ◽  
pp. 19-24
Author(s):  
O. E. Andreikiv ◽  
N. I. Tym'yak
Keyword(s):  
Local Corrosion ◽  
Loaded Crack ◽  
Electrochemical Model

Microstructures of Ti-1.5 w/o Ni Alloys with Mo and A1 Additions

1975 ◽  
Vol 33 ◽  
pp. 54-55
Author(s):  
Anna C. Fraker
Keyword(s):  
Corrosion Resistance ◽  
Beneficial Effect ◽  
Crevice Corrosion ◽  
Local Corrosion ◽  
Precipitate Size ◽  
Ni Alloys

Small amounts of nickel are added to titanium to improve the crevice corrosion resistance but this results in an alloy which has sheet fabrication difficulties and is subject to the formation of large Ti2Ni precipitates. These large precipitates can serve as local corrosion sites; but in a smaller more widely dispersed form, they can have a beneficial effect on crevice corrosion resistance. The purpose of the present work is to show that the addition of a small amount of Mo to the Ti-1.5Ni alloy reduces the Ti2Ni precipitate size and produces a more elongated grained microstructure. It has recently been reported that small additions of Mo to Ti-0.8 to lw/o Ni alloys produce good crevice corrosion resistance and improved fabrication properties.

scholarly journals A Segregated Approach for Modeling the Electrochemistry in the 3-D Microstructure of Li-Ion Batteries and Its Acceleration Using Block Preconditioners

2021 ◽  
Vol 86 (3) ◽  
Author(s):  
Jeffery M. Allen ◽  
Justin Chang ◽  
Francois L. E. Usseglio-Viretta ◽  
Peter Graf ◽  
Kandler Smith
Keyword(s):  
Degrees Of Freedom ◽  
Electrode Materials ◽  
Lithium Ion ◽  
Automotive Application ◽  
System Of Equations ◽  
Strongly Correlated ◽  
Electrolyte Depletion ◽  
Li Ion ◽  
Block Preconditioners ◽  
Electrochemical Model

AbstractBattery performance is strongly correlated with electrode microstructure. Electrode materials for lithium-ion batteries have complex microstructure geometries that require millions of degrees of freedom to solve the electrochemical system at the microstructure scale. A fast-iterative solver with an appropriate preconditioner is then required to simulate large representative volume in a reasonable time. In this work, a finite element electrochemical model is developed to resolve the concentration and potential within the electrode active materials and the electrolyte domains at the microstructure scale, with an emphasis on numerical stability and scaling performances. The block Gauss-Seidel (BGS) numerical method is implemented because the system of equations within the electrodes is coupled only through the nonlinear Butler–Volmer equation, which governs the electrochemical reaction at the interface between the domains. The best solution strategy found in this work consists of splitting the system into two blocks—one for the concentration and one for the potential field—and then performing block generalized minimal residual preconditioned with algebraic multigrid, using the FEniCS and the Portable, Extensible Toolkit for Scientific Computation libraries. Significant improvements in terms of time to solution (six times faster) and memory usage (halving) are achieved compared with the MUltifrontal Massively Parallel sparse direct Solver. Additionally, BGS experiences decent strong parallel scaling within the electrode domains. Last, the system of equations is modified to specifically address numerical instability induced by electrolyte depletion, which is particularly valuable for simulating fast-charge scenarios relevant for automotive application.

Local corrosion characteristics of a graphene-oxide-modified inner coating

2020 ◽  
Vol 27 (11) ◽  
pp. 3213-3226
Author(s):  
Ke-xi Liao ◽  
Xiao-xiao Li ◽  
Yi Jiang ◽  
Xin Liu ◽  
Hong Jing
Keyword(s):  
Graphene Oxide ◽  
Local Corrosion

A Nonlinear Observer SOC Estimation Method Based on Electrochemical Model for Lithium-Ion Battery

2021 ◽  
Vol 57 (1) ◽  
pp. 1094-1104
Author(s):  
Yuntian Liu ◽  
Rui Ma ◽  
Shengzhao Pang ◽  
Liangcai Xu ◽  
Dongdong Zhao ◽  
...  
Keyword(s):  
Lithium Ion Battery ◽  
Estimation Method ◽  
Lithium Ion ◽  
Nonlinear Observer ◽  
Soc Estimation ◽  
Electrochemical Model

scholarly journals Electrochemical Model-Based Investigation of Thick LiFePO4 Electrode Design Parameters

Modelling ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 259-287
Author(s):  
Robert Franke-Lang ◽  
Julia Kowal
Keyword(s):  
Lithium Ion Batteries ◽  
Porous Electrode ◽  
Lithium Ion ◽  
Size Composition ◽  
Design Parameters ◽  
Model Parameters ◽  
Electrode Structure ◽  
Transport Channel ◽  
Scale Particle ◽  
Electrochemical Model

The electrification of the powertrain requires enhanced performance of lithium-ion batteries, mainly in terms of energy and power density. They can be improved by optimising the positive electrode, i.e., by changing their size, composition or morphology. Thick electrodes increase the gravimetric energy density but generally have an inefficient performance. This work presents a 2D modelling approach for better understanding the design parameters of a thick LiFePO4 electrode based on the P2D model and discusses it with common literature values. With a superior macrostructure providing a vertical transport channel for lithium ions, a simple approach could be developed to find the best electrode structure in terms of macro- and microstructure for currents up to 4C. The thicker the electrode, the more important are the direct and valid transport paths within the entire porous electrode structure. On a smaller scale, particle size, binder content, porosity and tortuosity were identified as very impactful parameters, and they can all be attributed to the microstructure. Both in modelling and electrode optimisation of lithium-ion batteries, knowledge of the real microstructure is essential as the cross-validation of a cellular and lamellar freeze-casted electrode has shown. A procedure was presented that uses the parametric study when few model parameters are known.

Sign in / Sign up

Export Citation Format

Share Document