Comparison of two cobalt-free battery technologies
It’s no secret that the massification of electric cars requires batteries made with cheap raw materials, which means that they need to be cobalt free.
However, cobalt-free battery cells still don’t have great energy density, therefore reducing passive material is crucial to achieve overall good energy density and cost at the battery pack level.
The active material of battery packs is what stores the energy (cells) and its cost is variable (60-90 euros per kWh). The passive material is what assembles and protects the cells (cables, tubes, electronics and case), it doesn’t depend much on battery capacity and its cost tends to be more linear.
Battery cell makers such as CATL, BYD and SVOLT are developing module-less battery packs with CTP (cell-to-pack) technology. Without modules, the long prismatic battery cells connected in series are put in an array and then inserted into a battery pack, making it as simple as possible.
The simplicity of the CTP technology helps to achieve a good energy density at the battery pack level, even if the energy density of the cells isn’t amazing.
In this article, we’ll compare two alternative cobalt-free battery technologies, one from BYD and other from SVOLT.
SVOLT CTP technology
SVOLT battery cell specs
- Capacity: 226 Ah
- Nominal voltage: 3,81 V
- Max charging voltage: 4,35 V
- Energy: 861 Wh
- Weight: 3,59 kg (estimation)
- Dimensions: 575 x 21,5 x 118 mm
- Volume: 1,459 L
- Gravimetric energy density: 240 Wh/kg
- Volumetric energy density: 590 Wh/L
- Chemistry: LNMO
Hypothetical battery pack
- Cells: 92 (92s1p)
- Nominal voltage: 350,52 V
- Capacity: 79,2 kWh
- Total cell weight: 330 kg
- Total cell volume: 134 L
- Total pack weight: 391 kg (estimation from a GCTP of 84,5 %)
- Total pack volume: 215 L (estimation from a VCTP of 62,4 %)
- Gravimetric energy density: 203 Wh/kg (estimation from a GCTP of 84,5 %)
- Volumetric energy density: 368 Wh/L (estimation from a VCTP of 62,4 %)
- Active material cost: 5.544 euros (70 euros per kWh)
- Passive material cost: 1.000 euros
- Total cost: 6.544 euros (83 euros per kWh)
Unlike BYD, SVOLT doesn’t mention VCTP (volumetric cell-to-pack ratio) or GCTP (gravimetric cell-to-pack ratio) of its CTP battery packs. I’ll assume 62,4 % for VCTP and 84,5 % for GCTP, which is the same that we get with the BYD Blade battery.
Anyway, previously I thought that SVOLT was using the high-voltage spinel form of LNMO, which has a high operating voltage of 4,7 V and I was wrong! The LNMO battery cell from SVOLT operates at a lower voltage, which means that there’s room for improvement…
Operating at 4,7 V would represent a voltage increase of 23 % and an equivalent energy density increase, reaching 296 Wh/kg and 728 Wh/L.
BYD unveils the volumetric and gravimetric cell-to-pack ratio of the new battery packs
BYD Blade battery cell specs
- Capacity: 202 Ah
- Nominal voltage: 3,2 V
- Max charging voltage: 3,65 V
- Energy: 646 Wh
- Weight: 3,92 kg (estimation)
- Dimensions: 905 x 118 x 13,5 mm
- Volume: 1,442 L
- Gravimetric energy density: 165 Wh/kg (estimation)
- Volumetric energy density: 448 Wh/L
- Chemistry: LiFePO4 (LFP)
Hypothetical battery pack
- Cells: 110 (110s1p)
- Nominal voltage: 352 V
- Capacity: 71,1 kWh
- Total cell weight: 431 kg
- Total cell volume: 159 L
- Total pack weight: 507 kg (estimation from a GCTP of 85 %)
- Total pack volume: 253 L (estimation from a VCTP of 62,6 %)
- Gravimetric energy density: 140 Wh/kg (estimation from a GCTP of 85 %)
- Volumetric energy density: 280 Wh/L (estimation from a VCTP of 62,6 %)
- Active material cost: 4.266 euros (60 euros per kWh)
- Passive material cost: 1.000 euros
- Total cost: 5.266 euros (74 euros per kWh)
An energy density of 165 Wh/kg and 448 Wh/L is impressive for a LFP battery cell, but here there’s also room for improvement. LFMP is the high-voltage version of LFP and operates at 3,75 V, which represents a voltage increase of 17 % and an equivalent energy density increase. It would reach an energy density of 193 Wh/kg and 525 Wh/L.
Summing up…
We get more energy density with SVOLT’s CTP battery packs made with LNMO cells, but lower cost with BYD’s CTP battery packs made with LFP cells. Nonetheless, both batteries are great and still have room for improvement.
Both battery packs will be able to offer a usable capacity of at least 66 kWh, which would be enough for roughly a WLTP range of 500 km (311 miles) in a Hyundai Kona Electric for example.
Anyway, BYD is already producing its cobalt-free CTP battery packs, but we’ll have to wait a year to see SVOLT do the same…
Now I’m curious to know what CATL’s cobalt-free CTP battery packs will offer and what Tesla will show us in “battery day”. While I doubt that Tesla will ever produce its own battery cells, I wouldn’t be surprised if Tesla gradually replaced Panasonic and its cylindrical cells with CATL’s cobalt-free CTP battery packs… at least in some regions.
If Tesla doesn’t embrace cobalt-free CTP battery packs soon I’ll be extremely disappointed.
Great analysis as always. You actually have something interesting and new to say compared to all the InsideEVs, Electreks, etc. Keep up the great work, really exciting to see the battery progress. This is more important to adoption than any car model from any manufacturer. I did not expect that cobalt free batteries are back that quickly, but the recent announcement of SVOLT, CATL, and BYD have turned things around. I hope VW and other manufacturers are ready with their respective EV platforms, because they don’t want to miss out on this. Cheap & safe batteries that are good enough for most use cases.
Thanks, I really appreciate the positive feedback.
Only 1000$ more? I would prefer LMNO like a hundred times with that gravimetric density.
The problem is that SVOLT’s LNMO batteries are scheduled for June 2021. By then the difference could be much smaller, especially if BYD and CATL are already producing LFMP batteries.
Then we have:
LNMO: 240 Wh/kg and 590 Wh/L for 70 euros per kWh
LFMP: 200-225 Wh/kg and 525-550 Wh/L for 60 euros per kWh
Good analysis Mr. Pedro Lima: Yes, everyone are waiting for battery day. We waited for Cybertrk as well and we all saw. I think battery day will be to pushevs as cybertrk is for other green websites.
Gravimetric energy density: 144 Wh/kg is still ok, but look at the cost of € 74 / KWh (US$ 84). In a vehicle like Nissan Leaf with 40 KWh, it works out to € 2.960 (US$ 3,360).
That means Leaf should cost around US$ 25,000 in USA. But phony nissan mgmt is overcharging.
Unfortunately, all automakers are overpricing their electric cars. It almost looks like they don’t want them to succeed…
Hurrah, another battery article! Really looking forward to seeing how fast these batteries come into production. It seems like not too long ago that NMC-811 was some kind of amazing far off technology, and now it looks like it’s going to be superseded by cheaper and easier to handle alternatives even before it gets going.
Seems like things are really going to turn a corner soon for EVs and energy storage too.
Indeed.
A year ago I though that in 2020 we would be talking about NCMA batteries…
However, it’s the simple CTP technology the responsible for the comeback of LFP battery cells to electric cars. We’ll get cobalt-free batteries much sooner than previously expected.
Getting cobalt-free (and cheaper) batteries this quickly is a very encouraging development and a very welcome surprise. There are huge markets available for reasonably priced 45-60kwh EVs with these batteries.
I’m guessing that there will still be a market for NCM/NCMA cells as well, to go in higher capacity higher performance more expensive EVs where the volumetric density becomes a concern.
But CTP requires that you have a proper BEV platform and not a converted ICE platform.
Tesla will surely use the Chinese made batteries in markets that it can. Unfortunately those in the USA maybe stuck with Panasonic batteries for a while if you buy a Tesla. Nissan will use Chinese batteries too. EV in the USA are simply overpriced as compared to equally made Chinese models.