Lithium-ion batteries: what’s the charge?

By Claire Ginn

7 July 2017

Battery display screen

Lithium-ion batteries – a handy energy storage solution

We’ve been working on the battery for decades, and although our labs may now be a little more cutting-edge, our research question hasn’t changed: how can we get reliable energy when we need it? Until now, energy storage has been the missing link.

Batteries let us store electrical energy and use it later, which means we can save excess energy and then supply it when needed, responding to increased power demands quickly.

The good news is that technological advances are making battery storage technologies cheaper and more accessible. Batteries have seen significant cost reductions over the past few years, and based on demand and production efficiencies, we can expect they’ll come down further still.

How do batteries work?

Batteries use a chemical process to store electrical energy. This energy can then be called upon at a later time, or redirected back into the grid.

Batteries vary in size: a set of AAs can fit in your pocket, a typical household system may look like a small fridge or wall unit, and a commercial system could be as large several rows of shipping containers (usually around 0.5-1 MWh per container)!

Lithium-ion – the details

Lithium-ion (li-ion) batteries are used extensively in mobile phones, laptops, electric vehicles and digital equipment. They are responsive to quick input/output and also hold their charge well.

Lithium is a very reactive element, so a lot of energy can be stored in its atomic bonds (meaning a high level of energy density within the battery).

CSIRO Stored Energy Integration Facility

Energy storage superstars at our Stored Energy Integration Facility.

Although very common in small devices, li-ion batteries can also be deployed to suit much bigger purposes. But it is also worth looking at how smaller systems could be distributed throughout the network so that as well as providing grid stability, they could contribute to power quality in different locations.

One of the main challenges with a li-ion system is providing ‘synthetic inertia’. This is where large, traditional energy generators have substantial spinning mass that can provide bursts of power for very short durations when disturbances happen in the network. Other energy generation sources are less able to achieve instantaneous output unless there is a storage element involved. Inverter-based systems (like li-ion batteries) could achieve this, but as a reasonably new development it is less proven at large scale.

There may also some restrictions when using li-ion systems in different climatic conditions, unless carefully managed.

Other types of storage

When it comes to ‘saving a bit for later’, there are plenty of options:

As we look towards a low-emissions future, it’s clear that battery storage is about to become big business in our mission to integrate renewable energies like solar and wind into our daily usage.

Our Newcastle Energy Centre is testing and evaluating a variety of different battery storage systems at our Stored Energy Integration Facility.

We’re also looking into how to improve battery efficiency through salt baths.