Automotive Engineering - October 2021 - 18

BYD's
BLADE
RUNNER
" It's more robust than a module-based pack,
it's lighter per cell and it's about 20 percent cheaper. "
BYD's recently unveiled OceanX
concept EV features the company's
new 'platform 3.0' employing the
cell-to-chassis concept.
CTP - cell to pack. CTP technology directly integrates the
battery cells into the pack, without the use of modules.
BYD is, I believe, the pioneer to make this battery concept
available to the market, considering that most competitors
still use different sizes of modules. "
Going beyond the CTP concept, BYD recently
showed a new battery concept called CTC (cell-tochassis).
In CTC, the inherent safety of the LFP chemistry
enables the Blade batteries to be integrated directly
into vehicle body structures. BYD's 'e-platform
3.0' is a special pure electric vehicle structure that
uses the battery to increase the rigidity of the vehicle.
BYD engineers and chemists began work on the CTP
Blade concept about three years ago, Dr. Chen said. It
was purpose-designed for automotive, to give BYD a
competitive weapon against NCM's superior energy
density and cold-weather performance. " We have a big
stake in the LFP technology so we sat down to determine
how we can compete with NCM, " particularly
NCM811 which is " a big competitor " to the Blade battery.
(The 811 number of the nickel-rich layered oxide
NMC811 denotes 80% nickel and 1% each cobalt and
magnesium. While the chemistry offers high specific
energy density for EVs, its downsides include rapidlydepleting
capacity and voltage, battery experts note.)
In terms of chemistry, " there isn't a lot of innovation
you can do in a short time, " Dr. Chen admitted. " We did
patent the cell structure and mainly focused on structure
optimization. After a thorough analysis, we decided to
remove the module level; that was the breakthrough. "
Viewing an LFP battery's module level as unnecessary,
the engineers removed it. " In doing so we eliminate some
18 October 2021
BYD integrates the
Blade battery's BDU
and BMS into the pack.
mechanical parts, reinforcements, and some harnesses, " Dr. Chen noted.
" With the Blade battery we reduce weight, decrease overall pack volume
by about 50 percent, and increase the energy density. This makes a very
solid point for our chemistry. It's more robust than a module-based pack,
it's lighter per cell and it's about 20 percent cheaper. "
A robust design
The accompanying exploded view of the Blade battery shows its simplicity.
Typical dimensions of the compact, single-cell design are 905
x 118 x 13.5 mm (35.6 x 4.6 x .53 in.). The size can be customized. The
thin, blade-like cells are inserted into the pack in a blade-type array.
BYD engineers have also decreased the cubic volume of the battery
installation by 50%, improving overall vehicle packaging. From top to
bottom, there is a layer of cotton thermal insulation. Then there is the
AUTOMOTIVE ENGINEERING
ALL IMAGES: BYD
Automotive Engineering - October 2021

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