From the RSC's Chemistry World, 28 October:
With lithium-containing batteries facing
constraints on many of the metals they contain, Nina Notman looks at
whether its group 1 neighbour sodium can supply the answer
The lithium-ion battery powers much of our modern lives, a fact reflected in this year’s Nobel prize. It resides in devices ranging from very small wearable electronics, through mobile phones and laptops, to electric vehicles and ‘the world’s biggest battery’ – the huge 100MW/129MWh Tesla battery installed on an Australian wind farm in 2017.HT: the journal Nature, 28 October
‘Lithium-ion has a massive span of applications,’ explains Jonathan Knott, an energy storage researcher at the University of Wollongong in Australia. ‘It is being used as a hammer to crack every nut and we need to start getting a little bit more sophisticated in the use of the best tool for the job.’
A number of disruptive battery technologies are jostling to take a share of lithium-ion’s multibillion pound market – currently valued at over $37 billion (£30 billion), and projected to reach $90 billion within five years. For sodium-ion batteries, its developers have primarily (but not exclusively) set their sights on the large-scale, stationary market – such as Tesla’s Australian installation.
Size matters
John Goodenough, one of the 2019 Nobel laureates, played a key role in the development of the rechargeable lithium-ion battery cathode at the University of Oxford in the early 1980s. Before lithium-ion charge carriers were settled upon, Goodenough looked at using ions from the element directly below it on the periodic table – sodium. ‘However, because Li+ intercalation is faster than Na+ intercalation, our attention turned to rechargeable cathodes exhibiting Li+ intercalation,’ he tells Chemistry World.
The lithium cobalt oxide cathode was created, the graphite anode devised, and the rest as they say is history. ‘Lithium-ion technology was picked up by Sony in 1991 and its use exploded,’ says Mauro Pasta, a battery researcher at University of Oxford in the UK.
In recent years, however, sodium has been having somewhat of a revival, thanks to its availability. ‘Although there are sufficient supplies of lithium [on Earth], these are not necessarily located in convenient places. Sodium is ubiquitously accessible from the oceans of the world,’ Goodenough explains.
In addition, electrodes in lithium-ion batteries contain cobalt. Electrodes for sodium-ion batteries don’t have to. Cobalt is expensive and there are significant ethical concerns regarding its mining practices. It is sometimes referred to as the blood diamond of the elements. Safety is another potential benefit. The cells can be completely discharged and transported at zero volts, circumventing the increasingly stringent transportation regulations covering lithium-ion batteries.
In terms of advantages over other disruptive battery technologies, however, it is the similarities between the sodium- and lithium-ion battery that are the former’s biggest selling points and are smoothing its path to market. ‘Sodium ions have similar intercalation chemistry to lithium ions and so, not surprisingly, a lot of materials being tested for sodium batteries are similar to those used for lithium,’ explains Saiful Islam, a materials chemist at the University of Bath in the UK. The manufacturing processes are also similar. ‘Any of the [Tesla] Gigafactories that are producing lithium-ion batteries will be fully adaptable towards sodium-ion technology,’ Pasta says.
But the differences between the two go beyond the intercalation – charging – speed that Goodenough noted in the 1980s. A key issue is that because sodium ions are larger than those of lithium, the energy density of batteries containing them – the amount of energy that can be stored in any given volume – is naturally lower. This directs sodium technology towards stationary applications where the size of the battery doesn’t matter as much....MUCH MORE
A couple prior posts on sodium batteries along with our boilerplate caution:
October 2017
"A Stanford battery based on sodium may offer more cost-effective storage than lithium"
We've been tracking battery technologies for a long time and if pressed to condense the lessons learned into one sentence it would be: "Scaling up is hard".December 2017
That said we keep an eye on developments, as Intel's Andy Grove once said: "Success breeds complacency. Complacency breeds failure. Only the paranoid survive."...
"Innovation: How Long Before Sodium Batteries Are Worth Their Salt?"
There are at minimum a half-dozen different chemistries being investigated right now, on top of the recipe tweaks being implemented to get more ooph out of lithium or use less cobalt or re-jigger the anode or the cathode but the ongoing reality of battery research is the difficulty getting from lab-bench demonstrations to scaled up production. That said there are technologies that look to take on Mr. Musk's Australian Powerwall concept:...There are more, most of them showing even good ideas take time and bad puns have a curious attraction.
You should see the "What's Mooooving" headlines when cattle futures get going.
