Let’s not miss the sodium-battery bus

Earlier this month, a less-known UK-based company called Faradion put out a press release that spoke of a “major partnership” with an Indian company called Infraprime Logistics Technologies for “developing Sodium-ion batteries for commercial vehicles in India.

The announcement was eyebrow-raising. Sodium-ion batteries ready for commercial vehicles? Well, that meant something.

In the world of electrochemical batteries, lithium-ion is the king — due to its light weight, long life and ability to pack more power. There is one problem, though — lithium is scarce. Cobalt, which is usually a part of the battery chemicals cocktail, is rarer. Also, lithium-ion batteries heat up quickly, which means you need to spend more on building up safety. Therefore, there is a search worldwide for alternatives to li-ion.

Sodium-ion batteries have been knocking around for some time, but it was said that because they can’t pack much power (low energy density), they will be bulky. For this reason, it was always assumed that SIB would be more useful where space is not an issue, such as for large storage systems woven into electricity grids. Sodium-ion batteries for transportation would come, if at all, later.

Faradion’s press release, therefore, meant that the technology had matured quite fast. If so, where does India stand in sodium-ion technology?

From a close look at the status of research in India’s laboratories, it appears that India is not a laggard. In the past, India missed being in semiconductor and lithium-ion battery manufacture, but in sodium battery manufacture, which has a huge potential globally, the opportunity is still wide open.

Intense research is going on in several IITs and CSIR laboratories, such as the Central Electro Chemical Research Institute (CECRI). The search is for the right material for the four key components — cathode, anode, electrolyte and separator — and some good candidates have been discovered. CECRI, for one, is almost ready to offer the technology to the industry, other institutions are not much behind.

Scientists upbeat

Scientists are usually coy about talking of their ongoing research because of the uncertainty of outcomes, but in the case of sodium-ion technology their confidence is palpable. “Based on today’s advancement in battery technology, sodium-ion batteries can strongly compete with lead-acid and lithium-ion batteries that are being used in UPS, grid storage applications and future electric buses,” says Prof Venimadhav Adyam of IIT Kharagpur. Adyam’s team has worked in this area and is awaiting grant of patents for inventions of ‘gel polymer electrolyte’ and ‘nitrogen-doped nano carbon anode’.

Adyam has told BusinessLine that the cathode material developed at IIT Kharagpur is all locally sourced and has “storage capacity comparable to commercially available li-ion chemistries”. He also said that the gel polymer electrolyte makes the batteries flame-resistant, stable at temperatures up to 300 degrees C, and therefore, safe. Having achieved this, IIT Kharagpur is now looking forward to working with the industry for further research and commercialisation.

Prof Sagar Mitra of IIT-Bombay, who has also dirtied his hands working on Sodium-ion battery technology for five years, is similarly confident. “The future of sodium-ion battery in India is bright in terms of raw materials availability and ambient temperature operation,” Prof Mitra told BusinessLine . “However, we need to target correct chemistries for different power and energy applications.”

Mitra, like CECRI, has developed a complete cell (a battery is a collection of cells). Mitra’s cell, which uses a sodium-titanium oxide anode and vanadium oxide cathode, is of 1,000 mAH (or 1 AH) storage capacity and nominal voltage of 2.9 V and boasts of a life of 4,000 cycles. Efforts are on to raise the capacity to 2,000 mAH. (To compare, the conventional Duracell AAA (or thin) cell is 750 mAH and 1.5 V; a 6.5 cm tall Samsung cylindrical lithium-ion battery is 2,200 mAH and 3.6V.) Also, the energy density characteristic appears to be quite high — 180-200 Watt-hour per kg — which means it can pack more power. The energy density, then, gets close to 265 Wh/kg of lithium-ion batteries. (Petrol has 12,700 Wh/kg). These numbers show that sodium-ion is getting close to lithium-ion in performance, while being safer and cheaper.

Mitra’s cell shows “excellent performance in terms of specific capacity and energy density and can be well compared with Faradion.” And, since all the raw materials could be sourced within India, the cost of the product will be low.

CECRI has completed development of a 1,000 mAH, 3.2V sodium-ion cell and is ready to commercialise it. Dr A S Prakash, Principal Scientist, who is working on this, tells BusinessLine that several large companies are talking to CECRI to buy the technology. CECRI, incidentally, is building a factory with an investment of ₹100 crore to produce lithium-ion cells — a rare instance of a government-owned research institution getting into commercial manufacture. The facility, expected to be commissioned next year, would provide a platform to produce sodium-ion cells too, condensing the lab-to-market time.

Trial runs under way

So, there is good stuff happening in India, though the proof-of-pudding is in scaling up to commercial production. Mitra observes that “the sodium-ion battery is most suitable for large stationary storage applications.” However, sodium batteries for automotive applications is slowly getting within reach.

The first automotive user of sodium batteries is obviously commercial vehicles. Subodh Yadav, CEO of Infraprime Logistics Technologies, expects to put a sodium-ion battery powered truck on the roads possibly by January 2021. The company has been trial-running two electric trucks of 55-tonne capacity with lithium-ion batteries in the last six months and says they have clocked 90,000 km. About 50 vehicles are “in various stages of production.” These trucks, Yadav told BusinessLine , can save up to ₹15 a km in fuel cost, compared with diesel vehicles.

A sodium-ion battery powered truck could potentially be even more economical — costs would depend upon the number of batteries produced. Infraprime Logistics is trying to get sodium-ion powered trucks included in the government’s FAME-II scheme, to make them eligible for subsidies. If that happens, “we can achieve price parity with the diesel trucks,” says Yadav.

In sum, India is sitting on a unique opportunity to lead in an area that the entire world is interested. Importantly, sodium-ion technology provides a way out of dependence on China for batteries. A good research foundation exists, but then, in India, many technologies (including semiconductors and lithium-ion) have disappeared into the deep chasm between laboratories and the industry. Scientists’ focus is typically on getting their findings published in a high impact-factor journal; the industry is too risk-averse to bet on new technologies.

This is true anywhere in the world, but other countries have mechanisms to bridge the gap. For instance, the US’ ‘Advanced Research Projects Agency-Energy' (ARPA-E) provides a sort of a venture funding to emerging technologies.

“Similar high risk-high gain funding is essential for enabling Indian scientists and researchers to explore and demonstrate the commercialisation potential of their innovations which have been verified in lab-scale prototypes. Inventions happening in sodium-ion batteries will also benefit immensely from such a funding programme,” says Dr Satyajit Phadke, Manager R&D at Customized Energy Solutions. Phadke too believes there is immense potential for sodium-ion batteries.

The government of India does provide research funding to academics under the Impact Research Innovation and Technology (IMPRINT) schemes, but that is only for research and accordingly, the funding is also small. For instance, under the first phase of IMPRINT, 259 projects were provided funding of about ₹600 crore. IMPRINT does provide for a private sector participant in the research.

Whether the government should provide risk capital, or it is up to the industry to take a bet on potential technologies is a moot point. What is clear, however, is that a mechanism of technology transfer needs to be evolved quickly to ensure that India does not miss the sodium-battery bus.

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