Chemists have developed a grid storage solution that could help communities derive more of their energy from renewable sources.
Prof Linda Nazar and her colleagues from the Faculty of Science at the University of Waterloo developed the long-lasting zinc-ion battery, which costs half the price of current lithium-ion batteries. Their findings are published in Nature Energy.
The battery is said to use safe, non-flammable, non-toxic materials and a pH-neutral water-based salt. It consists of a water-based electrolyte, a pillared vanadium oxide positive electrode, and an inexpensive metallic zinc negative electrode.
The battery generates electricity through intercalation, where positively charged zinc ions are oxidised from the zinc metal negative electrode, travel through the electrolyte and insert between the layers of vanadium oxide nanosheets in the positive electrode. This drives the flow of electrons in the external circuit, creating an electrical current. The reverse process occurs on charge.
The cell is claimed to represent the first demonstration of zinc ion intercalation in a solid-state material that satisfies four vital criteria: high reversibility, rate and capacity, and no zinc dendrite formation. According to the University, it provides over 1,000 cycles with 80 per cent capacity retention and an estimated energy density of 450 watt-hours per litre. Lithium-ion batteries also operate by intercalation – of lithium ions – but they typically use expensive, flammable, organic electrolytes.
“The worldwide demand for sustainable energy has triggered a search for a reliable, low-cost way to store it,” said Nazar, a Canada Research Chair in Solid State Energy Materials and a University Research Professor in the Department of Chemistry. “The aqueous zinc-ion battery we’ve developed is ideal for this type of application because it’s relatively inexpensive and it’s inherently safe.”
The global market for energy storage is expected to grow to $25bn in the next 10 years. Manufacturers could produce this zinc battery at low cost because its fabrication does not require special conditions, such as ultra-low humidity or the handling of flammable materials needed for lithium ion batteries.
“The focus used to be on minimising size and weight for the portable electronics market and cars,” said Dipan Kundu, a postdoctoral fellow in Nazar’s lab and the paper’s first author. “Grid storage needs a different kind of battery and that’s given us license to look into different materials.”
Water in the electrolyte not only facilitates the movement of zinc ions, it also swells the space between the sheets giving the zinc just enough room to enter and leave the positive structure as the battery cycles.
The electrode material’s nanoscale dimensions and the battery’s high-conductivity aqueous electrolyte also improve its cycling life and response times.
The energy density of the battery is 1.62 Mj/Kg.
The energy density of a Lithium ion battery is around 0.50 Mj/Kg.
I imagine that if this can be made to work on a commercial scale the cost of the battery will be lower than Lithium ion assuming the cost of lithium is substantially higher than zinc.
This therefore sounds like an important breakthrough if it can be made to work on a commercial scale.
At the current price and life of lithium on batteries, storing one kilowatt-hour costs about 30p.
If the price/life combination dropped by a factor of 10, it would still be too expensive for storage. I suspect that a revolutionary new technology is this needed. We have been searching this for years and it is still nowhere on the horizon.
But the best solution by far is to abandon expensive, intermittent and unreliable wind and solar power and so remove the problem. These industries only exists because of huge subsidies and are one of the most expensive ways of reducing man-made carbon dioxide – a gas that has boosted agricultural output all over the world and produced no measurable global warming.
The unsubsidised price of onshore wind around the world is about US$35-70 per MW.hr. solar has been contracted as low as $29 but is generally around $60-90. Wind and solar tend to be complimentary, more wind at night and in winter more solar in summer and during the day. Ther are however short periods of no wind and no solar. The primary method of filling these gaps is hydro and biomass. A secondary method can be gas however at $8/GJ or above the breakeven for open cycle gas peakers is around 15p. The advantage of batteries is they can not only supply power to fill the gaps but absorb excess power when there is low demand or high supply. This improves the economics of all generating sources including nuclear, coal and combined cycle gas. Batteries respond faster than any form of generation and therefore reduce the need for “spinning reserves” as just in case backup for generation or transmission faults. They can also be placed in substations to handle local peak demand without the need to upgrade feeders, protection gear and transformers for 12-15 hours demand per year. They pay for themselves in reduced standby generation operating and capital costs, reduced transmission losses at peak demand and reduced distribution infrastructure investment even in a fully thermal grid. So when they are installed for these purposes anyway, the fact that they can absorb excess power from renewables and distribute it when needed is a bonus that actually reduces the cost of power
Brian could you breakdown your cost assumptions as I would be interested to see where you think the market is in cost and lifecycle
I agree totally with Bryan Leyland’s comments about the design of batteries. Given that the world has, foolishly, invested billions in wind and solar generation that provides totally unreliable generation, these developments could at least make the white elephants grey.
Totally disagree with you sir; investment in solar and wind and other renewables is proving to be a planet saver. The sooner we can disinvest in oil, gas, shale and nuclear the better. Our part of the planet is 6′ warmer than it should be due to those industries.
How do you know your part of the planet is 6 somethings (´is not as far as I am aware a unit of temperature) warmer?
How is this caused by nuclear power, which currently is one of the lowest emitters of CO2 over its life cycle?
Have you looked at the lifecycle CO2 balance for wind and solar?
Best regards
Roger
As well as stationary batteries such as the well publicised installation in Leighton Buzzard we should not forget smaller domestic batteries and those in electric vehicles which are “a beautiful match with wind turbines” and other renewable energy sources. See pages 194/5 of the late Professor David Mackay’s book sustainable energy without the hot air available fee to download at http://www.withouthotair.com.
I agree with most of Jack Broughton’s cooments, why spend even more money just to solve the instabilities and non availability caused by so called green power. It has got to be more fundamental than that.
Just remind me: which set of intellectual and technical pigmeys managed to, in effect, ‘set’ the various elements of our excellent centralised power generation and distribution industry against each other: in the vain and incorrect idea that such ‘competition’ would make them more efficient? I suppose the clue is in the word ‘industry’. It would never do to have such a powerful element of our society as an Industry: with all the attendant workforce and installations capable of being ‘high-jacked’ by those terrible Unions! Divide and Rule and sow Fear amongst the lower orders: classical conduct of those who have been in power for ever, no matter what the people have voted! They use ‘language’ and their control of such as the primary weapon in their armoury against the population. Technologists, scientists and Engineers use symbols and mathematics. And it is the latter which really is the currency the future and the vehicle for our gaining the control necessary for the actual advance and ascent of mankind!
Here here ….
In m opinion different kinds , technologies will work. LIB, Vanadaium flow as well as NaNicl all equally will find market and utillity in next ten yrs…