Stoichiometric Maximum Concentration - Lithium Ion Batteries

[Effort]

Hi,

I am trying to test the validity of a simple lithium ion battery model that I consctructed to better understand the internal stress caused by the diffusion. I have referenced several papers and I am currently looking at how to calclualte the partial molar volume for a given material. To do this I need to determine the stoichiometric maximum concentration(cmax)...ie the number of moles per volume that can possibly fit into a material. I am currently trying to figure out how many lithium ions can fit into a nickel-tin alloy (Ni3Sn4).

I have not been able to find any information about this. My guess is that I am going to have to divide the volume of lithium atoms into the spacing of the nickel-tin alloy.

Is there any set way of how to do this, or way to figure out the space avialable in the alloy?
Also, if there is another way to determine the partial molar volume besides that given by the equation to follow, I am all ears.


PMV = ((strain)*3) / ((y2-y1)(cmax))


Any suggestions would be greatly appreciated.

Thanks

 

[Achy47]

,

Dr. Smith

Hello Dr. Smith,

Thank you for your post and for your interest in understanding the internal stress caused by diffusion in lithium ion batteries. I can offer some suggestions on how to determine the stoichiometric maximum concentration for a nickel-tin alloy.

One approach you can take is to use X-ray diffraction (XRD) to determine the lattice spacing of the nickel-tin alloy. This can give you an idea of the space available in the alloy for lithium ions to occupy. You can then compare this spacing to the size of lithium ions to estimate the maximum concentration of lithium that can fit into the alloy.

Another approach is to use density functional theory (DFT) calculations to model the structure of the nickel-tin alloy and determine the space available for lithium ions. This can also give you an accurate estimation of the stoichiometric maximum concentration.

In terms of calculating the partial molar volume, the equation you have provided is a common one used in thermodynamics. However, depending on the accuracy you require, there may be more complex equations or methods available. I would suggest consulting with a thermodynamics expert for more specific guidance on this equation.

I hope this helps and good luck with your research!

 

[oswaler]

for your question. I can understand your interest in testing the validity of your lithium ion battery model and determining the stoichiometric maximum concentration for a given material. This is an important aspect in understanding the internal stress caused by diffusion in batteries.

To determine the maximum concentration of lithium ions in a material, you can use a few different methods. One way is to use theoretical calculations based on the physical properties of the material, such as its crystal structure and interatomic spacing. This can give you an estimate of the maximum number of lithium ions that can fit into the material's lattice structure.

Another approach is to experimentally measure the maximum concentration by performing electrochemical tests on the material. This can give you a more accurate value for the stoichiometric maximum concentration.

In terms of determining the partial molar volume, the equation you have provided is a good starting point. However, it is important to note that this equation assumes a linear relationship between strain and concentration, which may not always be the case. It would be beneficial to also consider other factors that may affect the partial molar volume, such as the presence of defects or impurities in the material.

Overall, I would recommend further research and experimentation to accurately determine the stoichiometric maximum concentration and partial molar volume for your specific material. I hope this helps and wish you the best in your research.