Sodium-ion batteries already arrived

In case you haven’t noticed, we can already buy sodium-ion (Na-ion) batteries.

For example, with a simple search on AliExpress we can already find sodium-ion battery cells in cylindrical and prismatic formats for consumer use.

Depending on the manufacturer, the advertised cycle life varies between 1.500 and 4.000 cycles, while energy density stays between 125 and 140 Wh/kg.

However, since the mass production of this battery chemistry is extremely recent, production efficiency (mainly yield rate) and capacity are still low, so you can get much better deals on LFP (LiFePO4) batteries for now…

I think that it will take at least a full year until we can get better kWh cost with sodium-ion than with LFP.

Anyway, let’s sum up the potential of this new battery chemistry.

🔋 Sodium-ion batteries potential

👍 Pros

  • ✅ Low cost (below 40 euros per kWh)
  • ✅ Good cycle life (easily reach 4.000 charge/discharge cycles)
  • ✅ Good power density (high charge and discharge rates)
  • ✅ Great safety
  • ✅ Can be fully discharged to 0 V without damaging cycle life (great for shipping)
  • ✅ Phenomenal temperature tolerance

👎 Cons

  • ❌ New technology, production efficiency and energy density are still low

Sodium-ion battery voltage/capacity chart by Faradion
Sodium-ion battery voltage/capacity chart by Faradion

With so many advantages and just a few temporary downsides, it’s normal to expect great things from this battery chemistry.

Yield rate - that evaluates the quality and percentage of usable products from the total produced -, cost and energy density will improve over time. In just a year or two, not only will the manufacturing capacity and efficiency exponentially increase, but also the energy density is expected to reach 200 Wh/kg at the cell level. Considering a normal GCTP (gravimetric cell to pack) ratio of 85 % for module-less battery packs, we can expect an energy density around 170 Wh/kg at the pack level.

Sodium-ion will assist LFP/LMFP in powering the affordable energy storage revolution, I don’t expect a clear winner in this decade.

Na-ion vs. LFP by Faradion
Na-ion vs. LFP by Faradion

Given its phenomenal operating temperature range, I do expect sodium-ion chemistry to become more popular in countries with extreme climates.

As for high-nickel content chemistries, they will be left to applications where cost doesn’t matter as much as energy density, such as small portable devices, aviation or luxury electric cars.

In the next few years I hope to see some regions become role models and heavily invest in sodium-ion ESS (Energy Storage Systems) megaprojects to finally clean up their electrical grids with renewable energy. There are no more excuses for us to continue poisoning the planet we share.

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