• supersquirrel@sopuli.xyz
    link
    fedilink
    English
    arrow-up
    33
    ·
    edit-2
    1 day ago

    HiNa supplied sodium-ion batteries for JAC Motors in 2023. Early batteries had lower gravimetric energy density (145 Wh/kg) and volumetric energy density (330 Wh/liter) than LFP, but sodium-ion batteries have already improved since then. They have outstanding temperature range, yielding 88% retention at -20°C. For reference, the discharge capacity of NMC at 0°C, −10°C and −20°C is only 80%, 53%, and 23% of that at 25°C. The HiNa batteries had a cycle life of 4,500 cycles with 83% retention and a 2C charge rate, but even better sodium-ion batteries are on their way.

    These developments point the way to much more. The cost of sodium battery materials is much lower than for any lithium battery. There are no resource bottleneck materials like cobalt or lithium to contend with. In addition, aluminum can be used for electrodes, whereas lithium requires copper for one of the electrodes. Carbon or graphite and separator materials will be similar, but in all other respects, sodium has much lower material costs. Compared to LFP, sodium does not require phosphorous, a substance that is almost exclusively sourced from one state in north Africa, nor lithium, a relatively abundant but more expensive substance than sodium. LFP cannot compete on material costs or temperature range, and both BYD and CATL expect to phase it out first in energy storage. ‌