CATL’s NCM 811 battery cells are problematic

CATL NCM 811 prismatic battery cells (202/170 Ah)

GAC Aion S was probably the first electric car to be available with NCM 811 battery cells and expectations were extremely high for this model.

However, its 58,8 kWh (96 x 3,6 V x 170 Ah) battery pack made with NCM 811 cells from CATL suffered some serious safety problems that damaged the reputation of this battery chemistry.

After three spontaneous combustions GAC decided to abandon NCM 811 from CATL and adopt safer NCM 523 cells from CALB.


NCM 811’s poorer safety and stability and NCM 523’s higher performance-price ratio prompted GAC NE’s shift to the NCM 523, the report cited an Industrial Securities’ analyst who preferred to remain anonymous. But other electric models, including Xpeng’s P7, Volkswagen’s MEB, Nio’s ES6 and BMW’s plugin-hybrid model X1 are still equipped with CATL’s NCM 811 batteries.


GAC Aion S powered by CATL NCM 811 battery cells


While CATL denies the rumor that suggests it’ll abandon the production of NCM 811 battery cells, the damage is done.


We won’t give up the 811 battery because this is the necessary route to strive for dominance and power of discourse in the traction battery area. Relinquishing the 811 battery means abandoning the high-end market.


Even if CATL manages to completely solve the safety problems of its NCM 811 battery cells, perceptions are important and now some automakers will think twice before ordering them.


Anyway, since there’s no future for EV battery cells that use cobalt, this might be an opportunity for CATL to swallow its pride and start focusing on its cobalt-free LFP (LiFePO4) battery cells for electric cars – that are safer and cheaper to produce.

CATL really needs to catch up with BYD and Guoxuan that are now leading in energy-dense cobalt-free CTP (cell-to-pack) batteries.



More info:

Pedro Lima

My interest in electric transportation is mostly political. I’m tired of coups and wars for oil. My expectation is that the adoption of electric transportation will be a factor for peace and democracy all over the world.

22 Responses

  1. James says:

    All I can say is if you want to know what’s really going on with EV and batteries read PushEVs.

  2. Famlin says:

    Already CATL is a leader in LFP, I guess they will just ramp up the LFP production while just maintaining NCM 523/811 for few high end models.

    After all, a full size BEV like BYD Han can run on LFP, why not other smaller models. This year, LFP would have reduced the leadership with NCM.

    And more low speed EVs are moving from lead-acid to LFP.

    May be this could be the reason, Tesla is sticking with cylindrical cells for structural integrity. Today, there is another big news about Tesla buying lot of lithium.

    • Pedro Lima says:

      The problem is that CATL focused too much on NCM 811 and is lagging behind regarding energy density of LFP.

      CATL’s LFP battery: 125 Wh/kg (used in Tesla Model 3)
      BYD’s LFP battery: 140 Wh/kg (used in BYD Han EV)

      Guoxuan is already aiming to reach 180 Wh/kg before this year ends.

      • Famlin says:

        CATL has only 125 Wh/kg, but they also have the lowest cost at $80 / KWh at the pack level as per the earlier reuters report. I dont know whether BYD has reached this low a cost.

      • Doggydogworld says:

        125 Wh/kg is pack level density. Isn’t some of that weight due to Tesla including a bunch of electronics inside their Model 3 pack? Their NMC pack is 140 Wh/kg, also pretty low.

  3. Hudini says:

    Can we compare NCM 811 – 523 – LFP in chemistry, price, energy?

  4. sir_pece says:

    And now something completely different 🙂

    Did anybody noticed Daimler solid state batteries for buses:

    I thought this technology is still years away of commercial use.

  5. Rodri says:

    Really bad news as many car programs were depending on this new cell and shifting production to other type of cell or manufacturer can take years (resources allocation) so if the story is true this could delay EV adoption as CATL is producing 1 in 4 cells in the world.

  6. Leo B says:

    So far it’s been unclear what causes the problems. Below is link to an article with an analysis I’ve seen several times (but probably all from the same source):
    -Initially (2019) there was a production problem with CATL’s NCM811. Impurities in the cells itself caused short circuiting. But that problem is resolved.
    -Now the problem is pack design (cell-to-pack??) and cooling, which causes the cells to overheat.

    By the way, GAC has replaced CATL NCM 811 with China Aviation (CALB) NCM 523 cells for some of its Aion models.

    • Pedro Lima says:

      Thanks for the heads up.

      It seems that CATL aims to adopt CTC (cell-to-chassis) battery packs, similar to Tesla I guess.

      • Leo B says:

        Yeah, I think Moneyball has tweeted a quote of the CATL chairman, who said something like that. Now CATL has joint ventures with several (most) of the large Chinese car producers. I guess these joint ventures are mainly for pack assembly, but maybe cell production as well. If these joint ventures would produce entire platforms with batteries installed, a larger part of the car manufacturing revenue would go CATL’s way. So it makes sense for them.

      • Pajda says:

        Intereting chart Pedro, I know that “NCM 355 Module” is standardized module with 12pcs of VDA-PHEV2 format prismatic cells, the 355 number is a lenght of this module in mm. The “NCM 590 Module” is a new MEB module with 590 mm length. CATL and SVOLT already design a prismatic cell format for this module with 156 Ah capacity and so there will be only 12pcs of them in MEB module. VW is for now in EU using modules with the same dimensions with 24pcs of pouch E78 LG Chem cells, where both cells and modules are made in Poland by LG Chem. I think that for China they will switch to prismatic. For US market I guess they stay with pouch cells but supplied by SK Innovation.

        By the way anyone knows who is using the “NCM 390 modules”?

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