BYD Blade prismatic battery cell specs and possibilities (update)
Large battery cells… why now?
Simpler battery packs made with fewer and larger battery cells weren’t possible with compromised platforms like MQB, however in skateboard platforms like MEB – specially made for electric cars -, they are not only possible, they are what makes sense.
If you’re wondering why Tesla is still using thousands of tiny cylindrical battery cells to assemble complex battery packs, it’s because when the automaker introduced the Roadster in 2008, high energy density battery cells were only available in that format (mostly used in laptops).
Only in late 2016, high energy density battery cells started to be available in pouch format, like the LGX E63 made by LG Chem.
In 2020, assembling big battery packs with tiny cells doesn’t make sense and I wouldn’t be surprised if Tesla announces a battery pack made with cobalt-free prismatic battery cells in “battery day”. This would be great, not only for Tesla, but also for electric bicycle manufacturers who would benefit from an immediate increase of cylindrical cells available on the market.
Battery costs roadmap by Volkswagen
Anyway, this article isn’t about Volkswagen or Tesla, it’s about the LFP cobalt-free prismatic battery cell used in BYD Blade Battery. Let’s see its specs and potential.
BYD Blade battery cell specs
- Capacity: 202 Ah
- Nominal voltage: 3,2 V
- Max charging voltage: 3,65 V
- Energy: 646,4 Wh
- Length: 905 mm
- Height: 118 mm
- Width: 13,5 mm
- Volume: 1,442 L
- Volumetric energy density: 448 Wh/L
- Weight: 3,92 kg (estimation)
- Gravimetric energy density: 165 Wh/kg (estimation)
- Chemistry: LiFePO4 (LFP)
Unfortunately I couldn’t find the weight of this cell. However, according to the MIIT (Ministry of Industry and Information Technology) catalog the gravimetric energy density at the battery pack level is 140 Wh/kg, which means 165 Wh/kg at cell level (considering a GCTP of 85 %) and a weight around 3,92 kg.
BYD Blade Battery is a module-less CTP (cell-to-pack) battery pack. 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.
BYD unveils the volumetric and gravimetric cell-to-pack ratio of the new battery packs
Now let’s see the specs of a BYD Blade Battery prototype.
BYD Blade battery pack specs (prototype)
- Cells: 92
- Capacity: 202 Ah
- Nominal voltage: 294,4 V
- Max charging voltage: 340,4 V
- Energy: 59,5 kWh
- Volume: 213 L
- Volumetric energy density: 280 Wh/L
- VCTP (Volumetric cell-to-pack ratio): 62,41 %
- Weight: 427 kg (estimation)
- Gravimetric energy density: 139 Wh/kg (estimation)
- GCTP (Gravimetric cell-to-pack ratio): 84,5 % (estimation)
With standard battery packs assembled with modules, on average the VCTP is 40 %, which means that the volume of the active material (cells) only represents 40 % of the total volume of the battery.
Real applications
The first electric car to use the BYD Blade Battery is the BYD Han EV that’ll be available with two battery capacities (65 and 77 kWh).
The 65 kWh battery pack will give a NEDC range of 506 km (314 miles), which in WLTP should be around 380 km (236 miles).
My guess is that this battery pack is made with 101 or 102 cells.
- 101 cells: 65,3 kWh (101 x 3,2 V x 202 Ah)
- 102 cells: 65,9 kWh (102 x 3,2 V x 202 Ah)
The 77 kWh battery pack will give a NEDC range of 605 km (376 miles), which in WLTP should be around 454 km (282 miles).
My guess is that this battery pack is made with 120 cells.
- 120 cells: 77,6 kWh (120 x 3,2 V x 202 Ah)
BYD Han EV with Blade Battery
The BYD Han EV is a long (4.980 mm) electric car, aimed to be an alternative to the Tesla Model S.
This leaves us with a question…
Can the BYD Blade Battery be used in smaller electric cars?
The BYD Han EV with its long wheelbase (2.920 mm) has no problem to accommodate a long battery. However, it’s interesting to know if a smaller electric car could also accommodate a BYD Blade Battery.
Let’s see how much space does the BYD Blade Battery use.
65 kWh battery pack (cells only)
- Cells: 102
- Capacity: 202 Ah
- Nominal voltage: 326,4 V
- Energy: 65,9 kWh
- Length: 1.377 mm
- Width: 905 mm
- Height: 118 mm
- Volume: 147 L
- Weight: 400 kg (estimation)
If we consider a VCTP of 62,41 %, the battery pack’s total volume is around 236 L. As for the battery’s weight it should be around 468 kg if we consider a GCTP of 85,5 %.
77 kWh battery pack (cells only)
- Cells: 120
- Capacity: 202 Ah
- Nominal voltage: 384 V
- Energy: 77,6 kWh
- Length: 1.620 mm
- Width: 905 mm
- Height: 118 mm
- Volume: 173 L
- Weight: 470 kg (estimation)
If we consider a VCTP of 62,41 %, the battery pack’s total volume is around 277 L. As for the battery’s weight according to the MIIT catalog it’s 549 kg.
So the answer is yes, a smaller electric car could accommodate a BYD Blade Battery.
For example, the 2020 Chevrolet Bolt EV gets an EPA range of 259 miles (417 km) from a 66 kWh battery whose size is 285 L and weighs 430 kg.
Given the high weight of the 77 kWh BYD Blade Battery, the 65 kWh version would be more suited for the Chevrolet Bolt EV. It would have an EPA range around 250 miles (402 km), but with a good TMS the LFP battery could be fast charged from 0 to 80 % in less than 30 minutes.
Moreover, with 80 euros per kWh at the battery pack level, the battery would cost 5.200 euros.
BYD Blade Battery prismatic cells
Summing up
The BYD Blade Battery helps the BYD Han EV to be great electric car and so far it’s the best alternative to the Tesla Model S.
Considering that the BYD Han EV is already set for European launch, Tesla really needs to unveil a cobalt-free battery pack soon…
However, I am more interested in seeing cobalt-free CTP battery packs introduced in smaller electric cars, more suited to European tastes. BYD isn’t alone in this race, CATL and SVOLT also aim to lead in cobalt-free CTP batteries.
Do cobalt-free batteries make electric cars more appealing, or is it something you don’t care about?
More info:
http://www.sum-battery.com/info/byd-blade-battery-acupuncture-experiment-revea-44343117.html
https://insideevs.com/news/424645/byd-han-prices-china/
https://mall.bydauto.com.cn/activity/landingPageCN/D057QG20EG99.htm
Thank you for this very well thought out article. BYD was first-to-market with the CTP architecture. But Great Wall’s SVolt is also touting their own version of this type. And SVolt is suggesting that theirs has the possibility of being a Million Mile Battery. Lots happening around the battery world. Especially in China.
I am a bit worried about BYD doing away with liquid cooling on the Han.
I would have to see some serious, third party characterization to those cells to believe that they really have similar longevity to Tesla’s liquid cooled packs.
AFAIK another advantage of LFP is that it has very low internal resistance and therefore generates less excess heat during charging, or allows faster charging with the same excess heat output as NCM. I would imagine this would counter lower pack voltages by allowing in increase in charging current.
Yes, more complex liquid cooling isn’t necessary with LFP. A good heat pump that climate controls both the passenger cabin and the battery is enough (like Renault ZOE).
Thanks, Pedro! Yes, I think removing cobalt (and nickel) is very important for cost and optics issues. LFP (with or without M) is a good story because it removes the controversial nature of cobalt as a criticism that fossil fuel boosters can use to attack EV tech.
Aren’t those ranges pretty low? I mean the Tesla Model 3 Long Range with a battery of around 75 kWh gets a range of 560 km WLTP and the VW ID.3 with 77 kWh gets a range of 550 km WLTP, so 454 km WLTP is pretty low.
Don’t forget that this is a big and heavy electric car that competes with the Model S, not 3.
BYD Han EV: 4.980 mm (length)
Tesla Model S: 4.976 mm (length)
With the 77 kWh battery it gets a NEDC range of 605 km (376 miles), while the Tesla Model S 75D gets a NEDC range of 490 km (304 miles).
https://ev-database.org/car/1070/Tesla-Model-S-75D
Maybe later BYD will make a smaller and more efficient Han EV to compete with the Tesla Model 3. It would be great.
Hello all,
If we imagine the 65kWh pack in an Ioniq level efficiency vehicle with skateboard design we would get roughly 520km of range WLTP. Let’s call it 450km real world range.
If we consider 250km stops a safe compromise for long distance travelling, that 56% of full range (450km). If 0-80% would take 30min, 10-66% would probably take around 21min. That’s a fully acceptable long distance stopping time for 95% of the people.
In fact I reckon a 55kWh LFP pack (€4.400) in a vehicle with Ioniq efficiency would be sufficient for 85% of the users also for long range travelling.
Yes, those ranges and recharging times are perfectly acceptable if the charging network is built out with 100 kW+ chargers.
Another problem is that Chinese models seem to be much less efficient than Hyundai or Tesla EVs. Let’s hope they catch up soon.
Of course, if Tesla decides to use LF(M)P in their vehicles, the experience will probably be very similar to their NCA vehicles since they will not compromise on the user experience.
Hi Camille.
I agree. The focus shouldn’t be in increasing battery capacity alone, automakers should also improve efficiency.
A 55 kWh battery that charges from 0 to 80 % in 30 minutes would be enough to make a super efficient electric car like the Hyundai IONIQ Electric appealing to almost everyone.
With 80 euros per kWh at the battery pack level, the battery would cost 5.200 euros.
How low could prices go now?
Hi Camille, while I agree with everything, the caveat is that the Ioniq is a very low vehicle, and the battery pack is located under the rear seat and the trunk. This BYD blade technology requires a skateboard type pack, which would raise the floor by ~14cm. Since the Ioniq is already very tight in terms of head room, especially in the back seat, the whole height of the vehicle would need to be raised to be similar to the LEAF or the e-Niro, which are ~12cm taller.
This would reduce the Ioniq’s efficiency noticeably, so perhaps it would be better to use the e-Niro as the model for this idea. The e-Niro has a WLTP range of 455km, but putting in the BYD blade cells would add weight, so there would be another reduction, so we could probably start with a real world range of 380-400km, which is right where the e-Niro lands with the EPA rating.
Highway speeds reduce that by ~15% to ~320km, so 70% (10-80%) of that is ~225km. This is 45kwh to recharge, which would be 20-25 minutes ideally.
Hi all, thanks for the responses.
Part 1
@Marcel, it’s good to be realistic but I think you’re being just a bit too conservative here. I we compare it to a Tesla model 3 (height 1.443mm), add 48mm battery height, 15mm because of lack of glass roof and add a further 30mm for improving the ergonomic posture (head room and leg angle) we end up at 1.536mm, which indeed is close to the E-Niro (1.570mm). The Ioniq is 1.450mm.
Yes, you’re right, I was being too conservative. The Model 3 is better starting point for this thought exercise, since it already has the skateboard battery pack and is very aerodynamic. I probably chose the Niro since it has the same efficiency engineering that the Ioniq does and a flat pack under the floor.
I rented a Hyundai Elantra for a family trip once, which is a similar size to the Ioniq, and we hated it. I couldn’t sit up properly in the driver’s seat due to the sun roof, and the low seats made everything feel cramped.
Part 2:
However one thing to keep in mind is that:
1 The Niro is not designed as a dedicated EV with focus on maximum efficiency (although it is quite efficient for what it is).
2 It’s a cross-over with not much focus on aerodynamic drag.
Taking a cross-over with relatively little focus on aerodynamic drag based on a non-EV-dedicated platform is not a realistic reference I think.
The above excludes the possibility of using “foot garages” like the the Taycan (height 1.379mm btw) in the rear. Say 400mm long and full width. Relying more on the fast charge rate of LFP instead of going for huge range would increase the scope to go for such an approach even with the lower volumetric density of LFP. The 65kWh is 1.337mm in length. Say 55kWh would be 1.180mm. That is easily short enough to divide between underneath the front seats and below rear seats till the electric motor.
Yes, you’re right, splitting the pack into front and rear sections would work, and you might not even have to make the cabin longer than the Niro’s cabin. And using a sedan body shape, or the Ioniq’s body shape, to gain more aerodynamic efficiency would get much closer to the Ioniq’s efficiency. So the 6% increase in height that you listed above, if used crudely, cause a 3% decrease in efficiency.
And yes, I very much agree that a reasonably priced 55kwh car with 0-80% charging in under 30 minutes would be very appealling. With this type of battery, the EV premium could be massively reduced. Even if the EV premium is ~$3-4000 USD more than the comparable ICE, I’d think it would sell very well.
Smaller cells – 1000s provides failsafe if some cells fail – it will not impact the vehicle. With big cells, every cell failure will have significant hit on the system. With big cells it should be designed such that individual cells can be replaced by owner. I think not requiring liquid cooling system is a big plus as that can makes number of alternatives possible like quick battery replacement centers instead of fast charging.
With thousands of cells there’s a lot more chances that some of them go bad. Then, your battery pack will still work but it’ll make working cells more and more unbalanced over time.
In a module-less battery pack detecting and replacing a damaged cell is much easier and cheaper. In standard battery packs you either have to replace an entire module or pack.
I also think that in most cases liquid cooling is not required. A simple heat pump should provide decent climate control for the cabin and battery.
More repair friendly batterie pack design will increase average life time of a car and reduce the environmental impact of the car.
Pedro
Consider the “traditional” Li-FePO4 GSF46160M-28 cell produced by Gushen-Power.
https://www.gushenbatterys.com/lithium-battery/lfp-battery/28ah-lifepo4-battery-cell.html
3.2 Volt
28 Ah
0.665 kg approx
135 Wh / kg
1 C standard charging rate
5 C continuous discharging rate
10 C intermittent discharging rate
Say they sell them to VW $50 (FOB price) per kWh in very large quantities.
18 kWh would only cost $900 and weight 135 kilogram at cell level.
After 10 years usage, the net usable energy would drop to 12 kWh.
Considering a 18 kWh energy requirement per 100 km, after 10 years usage, the practical real world EV range would still be 65 km.
Given the 5 C continuous discharging rate, applied on the 12 kWh net usable energy after 10 years usage, the practical real world power delivered by such battery would still be 60 kW, with intermittent peaks easily reaching 90 kW.
This enables VW to sell serial-hybrid MEB car starting from $19,990.
Hi Pedro, thanks for another great article. Cobalt free batteries are more appealing, but it wouldn’t be a deal breaker for me.
I was thinking about charging speeds and how they relate to the lower voltages on LFP batteries, but realized I don’t know how many Amps 150 kw chargers can push to the car. I know 50kw chargers are limited to 125A, so with a lower voltage battery charging speeds would be limited to 40-42kw. I tried to find what the Amp rating is for the 150kw chargers that are being deployed now like the Ionity chargers, but my google skills aren’t that good.
I found a references to 375A but the article wasn’t clear and was from a few years ago, is this correct? If so, this battery could then charge very fast. If the charger is limited to 200A, then charging speeds would be also limited to ~65kw.
The IONITY chargers can use up to 500 amps.
http://www.faen.es/wp-content/uploads/2018/10/Ionity-Joer-Lohr.pdf (page 4)
However, the lower nominal voltage of LFP battery cells isn’t a problem, we just need to connect more of them in series.
With NCA and NCM battery cells (3,65 V) we usually have 96 cells (or groups of cells) connected in series for the battery pack have a nominal voltage around 350 V. For a battery pack made with LFP cells we need 110 cells to roughly have the same nominal voltage.
Ok, thanks for the link. This means that on one of the 150kw chargers, the Han EV should be able to charge to the maximum 150kw (~3C) at lower states of charge, which is quite impressive.
I think I was conflating the cable limitation of 200A with the charger limitation. I probably remembered reading somewhere that charging cables need liquid cooling above 200 amps, so I was guessing that was the charger limit, but I couldn’t figure out how a 400V EV could get high charging speeds with a 200A limit. 500A makes much more sense.
The limitation of charging current is based on the charging cable technology, I was told that the most problematic part is the connector and its pins. Today, they are available cables and vehicle inlets supporting up to 630A, used by Tesla in its V3 Superchargers for both CCS2 (EU) and GB/T(China) standards.
I know it’s not related to smaller European focused cars, but something I just though of: Tesla could use something like these blade cells in their Cybertruck, as the Cybertruck is large enough to easily fit a large flat pack, and volumetric density isn’t as important, at least for the lower 2 trims. (250miles and 300miles)
A pack sized at roughly 2.0m x 1.3m would be around 125kwh, which should be enough to achieve an EPA range of 500km of their mid range version. I’m guessing the Cybertruck will have its consumption about 20-25% higher than a Model X’s 19kwh/100km, so about 25kwh/100km.
The base trim would probably need ~100kwh pack, so roughly 2m x 1m.
Truck and delivery van manufacturers could really take advantage of these batteries, I hope they start using them.