Hard to say without seeing the data.  If your LDH shows a battery-like behavior with plateaus in charge/discharge curves, you should not calculate capacitance, rather capacity. There are many people who publish high values of capacitance for battery materials, such as Ni or Co oxides/hydroxides in basic electrolyte. Those data are useless. The difference between these two classes of materials has been explained in the following articles: P. Simon et al, Perspective: Where do batteries end and supercapacitors begin? Science, 343, 1210-1211, 2014 and T. Brousse et al., To Be or Not To Be Pseudocapacitive? Journal of The Electrochemical Society, 162 (5) A5185-A5189, 2015.

خیلی هم عالی

No..Its never possible.

Always experimental capacity will be lower than the theoretical one. 

Dear Shambhulinga, 

Thanks for your answer, But I think it's better to say that:

See these two articles, and tell me about theoretical capacitances. Which role does "synergistic effect" play in composite materials?  Can  these  capacitances be calculated by the formula which is nowadays used for our calculations ? Or maybe this formula is not a complete one, and there is a term (synergistic effect) that is not included in this formula! So have a look to these two articles:

1) http://pubs.rsc.org/en/content/articlelanding/2015/nr/c4nr05880a

2) http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4250917/

The "synergistic effect" assumes that both materials work together and should both give its maximum output capacitance, so there is no term in the formula, it is just ideal.

Specific capacitance is usually calculated for pseudocapacitive materials as it takes into account specific molecular weights and charges which are easily identified. I would imagine it would be hard to quantify these for LDH enzyme, plus the calculation does not usually take into account the porosity of rGO.

Hard to say without seeing the data.  If your LDH shows a battery-like behavior with plateaus in charge/discharge curves, you should not calculate capacitance, rather capacity. There are many people who publish high values of capacitance for battery materials, such as Ni or Co oxides/hydroxides in basic electrolyte. Those data are useless. The difference between these two classes of materials has been explained in the following articles: P. Simon et al, Perspective: Where do batteries end and supercapacitors begin? Science, 343, 1210-1211, 2014 and T. Brousse et al., To Be or Not To Be Pseudocapacitive? Journal of The Electrochemical Society, 162 (5) A5185-A5189, 2015.

Agree with Yury.

In addition, for capacitive materials, either being double-layer capacitive or pseudo-capaticitive, the claim of theoretical specific capacitance without giving the potential range would not be helpful. This is because charge capacity is an absolute value, but capacitance is a normalised value which is the charge capacity normalised over voltage (or potential range).

Further, for double-layer capacitive materials, the capacitance is very much dependent on the electrolyte used. Whilst for pseudo-capacitive materials, the number of electrons transferred with reference to the formula mass is fractional in most cases, if not all.  This is because if a formula mass of the material  receives or losses an integer number of electrons, the electron transfer reactions becomes poorly reversible. These are just two factors of many that make it more unreliable to use the concept of theoretical specific capacitance.

Dear Mr. Lee Thanks for your explanations.

Dear Prof. Gogotsi Thanks so much for your response and suggestions. The articles that was suggested were really helpful.

Dear Prof. Chen thanks for your helpful explanations.

That depend on that type of materials you are dealing with. I expect LDH to exhibit faradaic behavior. In that is the case is wrong to calculate specific capacitance instead you calculate specific capacity since your material is behaving like battery material. I refer you to the following articles to help you with analysis  electrochemistry communications 60 (2015) 21-25 and Adv. Energy Mater. 2015, 5, 1401401

Dear Mr. Khaleed Thanks for your contribution. Just if it is possible, please tell me the precise citation of "Adv. Energy Mater. 2015, 5, ...", because I was not able to find the article due to the page number.

Thank you again 

I check the citation is correct which is Adv. Energy Mater. 2015, 5, 1401401, alternatively you can check by the title "Supercapacitors Performance Evaluation", it is authored by Sanliang Zhang and Ning Pan