I do not understand the point of half cell measuring of cathode or anode materials before testing them in a full cell. Any explanations or suggested literature?
Half-cell is measured normally against standard electrode with known potential at the condition of measurements. In that way, the half cell of the material we doing research, can be idealized. For instance:
Li+ + e --> Li (which is around 3.05 V versus NHE).
Now consider you have oxide material which can host the Li+ (intercalation or insertion)
MO + xLi+ + xe --> MLixO
The inserted lithium ideally, should be extracted, deintercalated in the oxidation process.
Say that you measure the potential of that material and it is 2.5 vs. Li/Li+
Then you know when you applying this material against other material (B) (in the cell not half-cell) which will be the cathode and the anode and you will know also the exact voltage of that cell. This material (B) is identified in smiliar way.
I suggest reading the Electrochemical methods. Fundamentals and applications (2ed., Wiley, 2001) by Bard A.J., Faulkner L.R. , or any other available reference of electrochemistry.
I hope this can help.
Half-cell is measured normally against standard electrode with known potential at the condition of measurements. In that way, the half cell of the material we doing research, can be idealized. For instance:
Li+ + e --> Li (which is around 3.05 V versus NHE).
Now consider you have oxide material which can host the Li+ (intercalation or insertion)
MO + xLi+ + xe --> MLixO
The inserted lithium ideally, should be extracted, deintercalated in the oxidation process.
Say that you measure the potential of that material and it is 2.5 vs. Li/Li+
Then you know when you applying this material against other material (B) (in the cell not half-cell) which will be the cathode and the anode and you will know also the exact voltage of that cell. This material (B) is identified in smiliar way.
I suggest reading the Electrochemical methods. Fundamentals and applications (2ed., Wiley, 2001) by Bard A.J., Faulkner L.R. , or any other available reference of electrochemistry.
I hope this can help.
There are many things to consider before you assemble full cell by analyzing half cell reactions.
You have to balance capacity/mass ratios.
Check the cyclability of half cells ...before get any idea about full cell.
Check polarisability of cathode and anode..
Select cut-off voltage of the full cell... and so on.
Thanks Nanda....
You said balance capacity/mass ratio. How the information form half cell can help us when we want to test full cell?
Also, for half cell measurement, we need to know all the electrochemical parameter about counter electrode, is that right?
The performance of the full cell can be judged with the help of combination of two different electrodes. In a half cell reaction, working electrode is coupled with known standard potential electrode ie. Li/Li+. This will gives the more detail information on the working electrode .Particularly for a single electrode, the electrochemical characteristics only depends on the nature of reaction and independent of whether the electrode is galvanic or electrolytic.
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