I need to calculate the specific capacitance in both F/g and mA h/g of a lithium ion capacitor. Is the calculation same as for supercapacitor?.
If you use EC lab, it can be directly calculated from software.
Here I'm giving the method to calculate specific capacitance/capacity from cyclic voltammetry (CV) and charge-discharge(CD):
Specific capacitance (F/g) for supercapacitors calculated from CV
C=∫Idv/(m*v*(Vf-Vi)
where, ‘∫Idv’ implies area under the CV curve, ‘m’ signifies mass (g) of active electrode, ‘v’ specifies the scan rate, ‘(Vf-Vi)’ is an functional potential frame.
Specific capacity (mAh/g) for rechargeable batteries calculated from CV
C=∫Idv/(3.6*m*v)
Specific capacitance (F/g) for linear/triangular CD curve (EDLC based supercapacitor)
C=I∆t/m(Vf-Vi)
where, , ‘I’ implies current intensity, '∆t' is discharge time.
But Specific capacitance (F/g) for non-linear CD curve (pseudocapacitance based supercapacitor)
C=2I∫Vdt/m(Vf-Vi)2
'∫Vdt’ symbolizes the area under the discharge curve only.
Specific capacity (mAh/g) for rechargeable batteries calculated from CD
C=I∆t/(3.6*m)
For further information, you can see my publications as well. I'm attaching a few here.
Article V2O5 encapsulated MWCNTs in 2D surface architecture: Complet...
Article Large scale flexible solid state symmetric supercapacitor th...
Article Chemically deposited Bi 2 S 3 :PbS solid solution thin film ...
Hi there,
I agree with Bidhan's answer and introduce perfect equations about the specific capacitance. And advice to check the following files to show more details about your topic.
Regards,
Thanks @bidhan and @Qhatan. I was confused in the conversion of F/g to mAh/g as I am shifting my research from supercapacitors to lithium ion batteries. As I started working and analyzing its results and reading the publications which both of you recommended, my problem solved. Thanks again.
please let me know how to measure current or current density
from capacity or specific capacity of battery