However there is a debate over what constitutes one of the 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 opponents are going to must work onerous to maintain up.
The prize that awaits is the potential 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, relatively than within the US. “We are able to swap forwards and backwards and select what battery we need to work with,” says Tan, explaining that, in future, his agency would possibly supply cells from the US – although these could come at a distinct price.
There’s one other consideration. Unigrid’s battery accommodates 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 underneath sure circumstances chromium-3 could type 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 are going to lift crimson flags,” she tells the BBC.
Ivana Hasa on the College of Warwick, who has no connection to Unigrid, agrees that it’s attainable for chromium-3 to type chromium-6 at very excessive states of cost, although she says this may be mitigated by how voltage is managed inside the battery. “Security assessments reported on the cell chemistry are very promising,” she says of Unigrid’s tech.
Tan says issues 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 type chromium-6, he says. “We have tried very onerous to attempt to produce it, we have overcharged it as a lot as we will… We have 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 onerous carbon as a substitute, or sodium iron phosphate pyrophosphate (NFPP).
On the whole, confidence round sodium ion batteries’ reliability has elevated throughout the previous few years, says Prof Dame Gray, which means they’re now discovering their method 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 firms that spoke to the BBC prompt 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 vitality dense as lithium ion batteries, which means they have to be barely larger and heavier with a view to present the identical quantity of energy.
The expertise has been improving, external on this entrance in recent times however, even so, you are not prone to see sodium ion cells in small, vitality hungry units comparable to smartphones. Bigger vitality storage options are the place most individuals count on sodium ion to dominate.
