Lithium Nickel Manganese Cobalt Oxide, also known as LiNiMnCoO or simply NMC/NCM is the best available chemistry for EV batteries. This chemistry is finally spreading in China.
The Chinese have been building good LiFePO4 cells for years. They are very safe, have great lifespan and are able to handle decent charge and discharging C rates, perfect for energy storage at home. But because of the low energy density they aren’t the best for EVs.
I remember the days that if you had an EV project you had to choose the LiFePO4 cells from Winston Battery (former Thunder Sky), CALB or Sinopoly. Those were the big three at the time.
Now, times have changed, LiFePO4 is no longer the best chemistry available for EV batteries. CALB and Sinopoly finally started to sell NMC cells. This is great news.
The best about these Chinese cells is that you are able to buy them fairly easy from online stores so they are great for small EV personal or university projects. Also pouch or prismatic cells make the task of building a battery pack a lot easier than cylindrical cells.
Just don’t expect to get second generation NMC cells yet. They use the magic Lithium Nickel Manganese Cobalt Oxide formula for the positive charged anode, but still use an all graphite negative electrode. The second generation NMC cells have higher energy density because of the mixed silicon/graphite cathode. With the silicon providing higher density and the graphite stability.
The replacement of LiFePO4 with NCM cells production for EVs isn’t the result of market’s magic invisible hand working. It’s Government regulation. The Chinese Government has passed legislation that requires EV cells to soon achieve an energy density of 200 Wh/kg. This is simply impossible with the LiFePO4 chemistry, but possible with improved NMC cells. This means that Chinese cell makers will now focus in improving this chemistry to reach the 200 Wh/kg goal.
Let’s go back to Sinopoly and CALB.
Sinopoly currently makes 20 Ah/3,6 V (72 Wh) NMC pouch cells. Regarding weight and dimensions each is 480 g and 228 x 160 x 6,2 mm (226,176 ml). This translates to 150 Wh/kg and 318 Wh/L.
CALB’s NMC cell it’s 22 Ah/3,7 V ( 81,4 Wh), 510 g and 227 x 161 x 7,2 mm (263,138 ml). This is 160 Wh/kg and 309 Wh/L.
But better cells are being developed by CALB.
CALB is pretty confident about the future and plans to increase production.
Sinopoly and CALB aren’t the only Chinese manufacturing NMC cells, but they have the advantage of making them available to everyone, we can easily buy them online. The better energy density of NMC than the “old” LiFePO4 cells also allows us to save money in shipping costs.
The alibaba.com website is always a good tool to discover new Chinese cell makers like Melsen that sell to individuals.
The 12,5 Ah/3,6 V (45 Wh) NMC pouch cell is 260 g and 179 x 88,5 x 8 mm (126,732 ml). We get 173 Wh/kg and 355 Wh/L. Not bad…
Chinese cells makers are now making first generation NMC cells able to achieve 150 Wh/kg and 300 Wh/L and can be easily bought. Great for small EV projects.
World’s best cell makers are already in second generation NMC, they can achieve 250 Wh/kg and 700 Wh/L, but unless you have a big company you can’t buy those.