Orange one is better than blue one though both are showing same discharge capacity but later one (blue) has more charge capacity then former (orange). Moreover, orange shows clear plateau region than other. But battery performance could not be decided by the single voltage profile, you need to run few tens of cycle to find the better one.

Hi Mohammed,

First of all the system is not LiMO2 because its capacity is around 272 mAh/g; however, capacity is more as seen from figure (~ 300 and above), The curve nature and the capacity suggest that it is probably Li2MO3 type of material or Li2MO3-LiMO2 composite material. Secondly, Li2MO3 material changes structure during first cycle which is seen from the curve (two plateau for blue but orange is slightly different).

Moreover, seen from two curve the orange color curve has less polarization loss compared to blue color curve. Further, the plateau region is quite good for the case of orange curve compared to slope nature of discharge curve for blue. So, result of orange color curve is better compared to blue. 

Hi Mohammed,

It is difficult to say which one of the curves is better. Anyway I agree to what Sudeep said about the system being not pure LiMO2. At least the blue curve is for me definitely a LiMO2 - Li2MnO3 compound. You can clearly see the two contributions in the charge curve:

The orange curve shows only a sloped profile, which is actually typical for LiMO2.

I have following questions:

- Do both curves correspond to the first charge?

- Why did you use such a negative cut-off voltage - i.e. less than 2.0 V for the orange curve?

Sorry for asking the first question. You already mentioned it was the first cycle.

Corina

I appreciate your answers. I agree with you that this material is solid solution of LiMO2-Li2MnO3. I think, because the blue curve is linear, therefore we can calculate the real remaining capacity at any discharge point which is very important in EVs.