However there is a debate over what constitutes the very best, and most secure, sodium ion battery design. Plus, more than one, external US firm working on this house has floundered in recent years, external.
China leads the world in sodium ion battery manufacturing at current so US rivals are going to need to work laborious to maintain up.
The prize that awaits is the opportunity of batteries made within the US with 100% US-sourced supplies. That is in contrast to lithium ion batteries, the place China dominates the materials, external provide chain in addition to manufacturing.
For Tan, China has helped his firm get to market. The Unigrid battery presently makes use of sodium ion cells made there, fairly than within the US. “We are able to change forwards and backwards and select what battery we wish to work with,” says Tan, explaining that, in future, his agency would possibly supply cells from the US – although these might come at a special price.
There’s one other consideration. Unigrid’s battery incorporates chromium-3 in its cathode. In a battery, electrons flow from cathode to anode, external when charging and in the wrong way when discharging or offering energy.
Prof Dame Clare Gray on the College of Cambridge, who’s co-founder of battery agency Nyobolt, factors out that beneath sure circumstances chromium-3 might kind chromium-6, a poisonous, cancer-causing material., external
“If you are going to go for sodium […] and you are going to promote security, then do not begin placing components in which can be going to boost crimson flags,” she tells the BBC.
Ivana Hasa on the College of Warwick, who has no connection to Unigrid, agrees that it’s potential for chromium-3 to kind chromium-6 at very excessive states of cost, although she says this may be mitigated by how voltage is managed throughout the battery. “Security assessments reported on the cell chemistry are very promising,” she says of Unigrid’s tech.
Tan says considerations round toxicity of the battery’s supplies are “overblown” and emphasises that Unigrid’s battery has handed certification and security assessments on the market in Europe and is presently present process such evaluations for the US market.
Third-party assessments haven’t been in a position to get the battery to kind chromium-6, he says. “We have tried very laborious to try to produce it, we have overcharged it as a lot as we will… We had been unsuccessful in producing chromium-6.”
The selection of cathode materials, or how the electrolyte – which separates cathode and anode – is formulated are key particulars influencing the efficiency and longevity of sodium ion batteries. Some producers will not be utilizing chromium for his or her cathode however laborious carbon as a substitute, or sodium iron phosphate pyrophosphate (NFPP).
Generally, confidence round sodium ion batteries’ reliability has elevated throughout the previous couple of years, says Prof Dame Gray, that means they’re now discovering their manner into grid storage functions.
Final December, LFP batteries – a comparatively low-cost type of lithium ion battery – were trading at $81 per kilowatt hour, external (kWh) whereas Unigrid’s sodium ion battery pricing is roughly $100 kWh, external.
Some corporations that spoke to the BBC steered sodium ion would possibly attain as little as $30 per kWh however analysts say considerably decrease prices could be many years away, external.
Sodium ion batteries are additionally not as power dense as lithium ion batteries, that means they have to be barely greater and heavier in an effort to present the identical quantity of energy.
The expertise has been improving, external on this entrance lately however, even so, you are not more likely to see sodium ion cells in small, power hungry gadgets corresponding to smartphones. Bigger power storage options are the place most individuals anticipate sodium ion to dominate.
