NMC Composition

NMC Composition can be difficult to understand at first and so here is a walk through the compositions and what they actually mean.

The 33%,33%,33%, in NMC111 is the composition of Ni, Mn, Co among themselves rather than the compound (Li Ni_x Mn_y Co_z O₂) as a whole.   

I have calculated the % m/m of all elements in the compound taking the atomic mass of each element into account and created the spreadsheet. 

Now the composition of Ni, Mn, Co in the oxide becomes 20,19,20 for NMC111

So if any of our colleagues  buy NMC111 and send it to the lab then they should not panic for not getting a report with 33% for Ni, Mn or Cobalt.

However the ratio of these elements in the compound remains almost 1:1:1 because atomic masses for Ni, Mn and Co are similar. 

Personally I prefer NMC333 to NMC111 because it reflects the amount of each element in the lithium oxide as a whole.

Hence I prefer NMC622 to say NMC311

At first I got confused with NMC955 then I realised it was something like NMC9,.5,.5

I suppose  NMC9525  is 9.5,.25,.25. Any way that is what I assumed for calculation. 

By the way if the ratio remained the same for NMCs it may not for NCA. Luckily there are not too many of them around. I use the one which is apparently used by Tesla:

Li  Ni_0.84  Co_0.12  Al_0.04 O₂     

0.84:0.12:0.04 would give a ratio of 21:3:1   however in the molecule as a whole we get 51:7:1 because the atomic mass of aluminium is almost half the others.

See also: Lithium Nickel Manganese Cobalt Oxides, Cathode