The Future of Battery Storage: Part 2
The Future of Battery Storage: Part 2

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The Future of Battery Storage: Part 2

MARCH 22, 2021  |  MATT ROBINSON

Last week, we learnt all about why battery storage is so important for the world’s transition to Net Zero. And why we need to progress beyond today’s battery technology. If you want to catch up, you can read Part 1 of the blog below. This week, our Head of Sustainability, Matt, is delving into some up-and-coming batteries that might be making an appearance in the near future…

1. Liquid Metal Batteries

The liquid metal battery was developed in 2010 by MIT professor Donald Sadoway. It could be the answer to a key issue associated with current battery technology – the requirement of expensive rare metals. Instead, liquid metal batteries are made of magnesium, salt and antinomy (a metallic element), all cheap and abundant materials.

“If you want something to be dirt cheap, make it out of dirt.” - Donald Sadoway

Donald Sadoway, pioneer of battery technology
Photo credit: allthingsd.com

Liquid metal batteries offer multiple other benefits. Their manufacturing process is simple. They show no degradation because the metals are in liquid form. They are easy to transport because their contents can be returned to a solid state by cooling, removing the possibility of short-circuits. And, finally, they can supposedly achieve all of the same grid-balancing and reactivity benefits that lithium-ion batteries can. So what’s the hold up?!

 

Since Professor Sadoway first created the liquid metal battery, he and his company ‘Ambri’ have been working to bring it to market. Early lab testing did not prove as successful as they had hoped. However, recent significant investments from Bill Gates and other financial backers have led to positive developments in Ambri’s mission. This is certainly a technology to look out for in the next 10 years.

2. Organic Radox Flow Batteries

Redox flow batteries are essentially made up of two tanks of oppositely charged fluids that are pumped past each other within a ‘cell stack’. The main benefit of flow batteries is that they can be scaled up or down in size fairly easily. Increasing the volume of the tanks means more liquid can pass through and so more energy can be stored. This could be highly significant when developing grid-level electricity storage.

 

Current models of radox flow batteries have some issues. The main problem is that their electrolyte (the liquid inside them that conducts electricity) is made from Vanadium – a rare metal – and a rather toxic acid solution. Manufacturing these batteries at scale would therefore pose environmental and potential health risks.

 

To combat this, scientists have developed a new type of radox flow battery which doesn’t require acid and is made from organic materials. This organic version of the flow battery shows real potential – it could be used at grid level but also scaled down for use in businesses and even homes within the next 10 years. The next step for this technology is to move it from the lab into the real world.

3. Liquid Air Batteries (cryogenic energy storage)

Liquid air battery.
Photo credit: telegraph.co.uk

A liquid air battery does what it says on the tin. It draws in air from its surroundings and transforms it into a liquid which can be stored! It does this by cleaning the air, drying it and then cooling it to -196 degrees Celsius. The process condenses the air down in size by a factor of 700 – in other words, 700L of breathable air becomes 1L of liquid air.

 

When there is a demand for electricity, the stored liquid air is heated and expands back into its original state. As it does this, the air flows through a pressurised tube, turning a generator and creating electricity.

On its own, liquid air battery technology is not very efficient. The process of turning air into liquid air uses electricity, and you only get about 25% of that electricity back when the battery is discharged. However, by using techniques such as capturing and reusing the excess heat and cold, the efficiency can be increased to as much as 60-70%.


Given that all of the components of liquid air batteries are readily available within the supply chains of gas and power industries, this is a technology that has few barriers to real market entry. As with the redox flow battery, all that is required to scale up liquid air batteries is larger storage tanks. The key will be finding the sweet spot between price and efficiency.

One of the companies pioneering this technology is Highview Power, based in Manchester. They are currently undergoing numerous projects in the UK and further across the globe to get liquid air batteries up and running. They have also put together this handy diagram to help visualise how the whole process works.

How a liquid air battery works
Photo credit: highviewpower.com

In my opinion, liquid air batteries will serve as an integral part of our journey to Net Zero, providing a reliable and sustainable option to support national electricity grids. Despite this, they cannot be scaled down to be used at residential or even commercial level. Therefore, liquid air batteries cannot fully replace lithium-ion batteries. Instead, the two technologies could work well alongside each other.

What's Next for Battery Technology?

The next decade is going to see a radical change in the way our electricity grids function. At a global scale, it is vital that countries and businesses stay ahead of the curve and provide the necessary funding to the companies and research institutes driving the renewable revolution. It is also critical that developing nations are not left behind. They will require support from the global North to bring their systems and infrastructure in line with Net Zero targets.

 

It’s an incredibly exciting time for battery technology and there are some fantastic ways in which we could build a more sustainable, more reliable energy storage network for a low-carbon future.