I found that 1/Q = 1/Q+ + 1/Q- for specific capacity, I will explain my problem.
Let's imagine that my positive electrode is 300 mAh/g
my negative electrode capacity is also 300 mAh/g
If i do a full cell with one gram of each electrodes, what will be my battery capacity.
To me i should be able to charge and discharge my battery for 300 mAh because those are my electrodes capacity meaning I could transfer n(electron) = 300 maH/ Faraday constant
Am I correct about it or am i missing something?
Dear Mathieu,
In practice most of the full cell systems are not balanced 1:1 in term of anode/cathode specific capacity, instead 1.1:1 or 1.05:1 anode/cathode ratio. Thus the cathode material is protected from over charge as its capacity is limiting the cell, providing improved safety. So to charge/discharge your cell you have to set the currents considering your cathode material, and the output of the cells will be mostly correlated with your cathode capacity.
For systems dedicated to power applications, 1.2:1 to 1.5:1 can be applied for further protection of the cathode.
For your example with 1:1 ratio, I think its quite hard to say which capacity you could get, as the two electrodes may undergo different capacity decay.
Sincerely,
Hello,
I can agree with Youn. As far as I know, the cell can delivers as much capacity as the limiting electrode allows. In most of the cases, the cathode is that one. In your example, Mathieu, it means that the utilizable capacity is 300mA for 1g active material.
Regards,
Bence
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