StoreDot, an Israeli battery startup, announced another major milestone related to its silicon-dominant anode lithium-ion cells (NCM 811 cathode), which are envisioned for extreme fast charging.
The 30 Ah pouch battery cells (production ready format already available for global OEMs for testing) withstood more than 1,000 fast charging cycles until the capacity decreased to 80% of the initial value.
During the experiment, the cells were consecutively charged (10-80% state-of-charge window) at a relatively high current (in 10 minutes), and then discharged at about 1C current (in 60 minutes). Considering the ambient temperature of 35°C, that's a pretty tough test.
On top of that, we must remember that those are pretty energy-dense batteries with energy density of 330 Wh/kg and 740 Wh/l ("*electrodes and electrolyte only").
"StoreDot’s ‘100in5’ cells repeatedly charged from 10 to 80 percent capacity in just 10 minutes and then discharged for one hour before recharging. The EV cells achieved over 1000 of these extreme charging cycles consecutively before degrading below the 80 percent of the original capacity threshold. No noticeable degradation occurred within the first 600 cycles in which the cells were consecutively fast charged between 10 to 80 percent."
For a theoretical 75 kWh battery and an initial EV range of 358 miles (576 km), 1,000 cycles (10-80%) would be an equivalent to probably more than 225,000 miles (362,000 km) and the vehicle would still maintain 80% of range - 286 miles (460 km).
Test results:
- 30 Ah pouch cell
- lithium-ion
NCM 811 cathode
silicon-dominant (about 40%) anode - energy density:
330 Wh/kg
740 Wh/l
"*electrodes and electrolyte only" - ambient temperature: 35°C
- test: 10-80% state-of-charge (SOC) window
10 minutes charging (6C current)
60 minute discharging (1C current) - result: over 1,000 cycles until reaching 80% of the initial capacity
Yaron Fein, StoreDot Vice President R&D
“I am delighted to announce that not only have we achieved our target but have also exceeded it – and we already have in our labs enhanced formulation that allows us to show further improved performance. This is the first time ever that cell performance of this magnitude has been achieved. The results stand testament to StoreDot’s relentless R&D drive, the enthusiasm of everyone in the company and to the Extreme Fast Charging vision we share with our partners.
StoreDot says that the first cells (energy density of 300 Wh/kg and 700 Wh/l) are now being shipped to global automotive OEM partners, while at the same time the company anticipates further improvements before the end of this year.
Series production of "100in5" battery cells (100 miles of range replenished in 5 minutes) will start in 2024. The long-term target is to achieve a range replenishing speed of 100 miles in 2 minutes.
StoreDot says that other form factors than pouch type are also under development - it includes the cylindrical type and prismatic type.
Targets:
- "100in5" - mass production target: 2024
(100 miles of range replenished in 5 minutes) and about 300 Wh/kg - "100in3" - to be released in 2028
(100 miles of range replenished in 3 minutes) and about 400 Wh/kg - "100in2" - "within a decade" (planned for 2032)
(100 miles of range replenished in 2 minutes) and over 500 Wh/kg
