The Future of Nanomaterials-based EV Batteries

Article By : Liam Critchley

Automotive manufacturers are starting to turn towards using nano-enhanced EV batteries to get the most out of the improved conductivity and charge carrier properties of some nanomaterials.

After years of being at a high price point, electric vehicles (EVs) are starting to become an affordable option for consumers. Nevertheless, there are still a lot of improvements that can be made to the batteries used in EVs ― especially around charging times and driving range ― and automotive manufacturers are starting to turn towards using nanomaterials to get the most out of their EV batteries.

Mercedes is now the latest company to announce that they will soon be using nano–enhanced EV batteries in some of their electric SUV vehicles.

Interest in nanomaterials

The EV market has faced a lot of challenges over the years, from slow charging to poor usable ranges and oversized batteries that are commercially unfeasible. There has been interest in nanomaterials for EV batteries over the years because not only can they help make the overall battery size smaller, but it can also utilize some of the excellent conductivity and charge carrier properties of some nanomaterials.

Some of the conductive nanomaterials that have been of interest have also showcased their potential for EVs in other applications such as ultracapacitors, where they are known to rapidly store charge. Taking advantage of these properties of nanomaterials has taken time to commercialize, but we’re now at a point where we’re going to soon be seeing nanomaterial batteries in cars that will be on public roads.

China: First to market

GAC Group’s Aion V (Source: GAC Motor) (Click image to enlarge)

The first major development in the EV battery market came from the GAC Group in China when it was announced that graphene batteries will be used in their new Aion V car in the latter end of 2022 following years of testing. This marked a significant development for nanomaterial use in batteries, never mind EV batteries specifically, and it is of no surprise that China was the first country to capitalize on this given that they have a huge interest in graphene.

However, it wasn’t the first major announcement in the automotive space for graphene. This came a few years prior when Ford announced they were to use graphene in their F–150 and Mustang vehicles, but this focused more on the composite, structural side of the vehicle and not the electronics side.

While it’s been easy over the years to integrate graphene into composites for more structural applications, integrating it into electronics systems has been more of a challenge. So, the development of these batteries is important for the development of graphene electronics, as well.

Even though the Aion V is going to be the first to market with a graphene battery (using graphene as the anode instead of graphite), the test results coming out suggest that it can charge from 0% to 80 % in just 8 minutes and has a range of 1000 km. So, while there’s the potential for graphene to challenge the status quo, the real–world charging and range values will have to wait until the end of 2022. Nevertheless, it opened the door for a wider adoption of nano–enhanced EV batteries.

Mercedes to adopt nano-enhanced EV batteries

While the graphene battery development is impressive, the biggest news to come out recently is that Mercedes will be working with Sila Nanotechnologies Inc. to develop a nano–enhanced battery for their electric G–Class SUV vehicles. In these batteries, the anode material is composed of silicon nanoparticles instead of graphite.

This makes this development even more significant because they are using silicon anodes rather than carbon–based anodes. Silicon anodes have long been researched and proffered for Li–ion batteries because they have a much higher theoretical energy density than graphite. The constant charging and discharging cycles in a battery, however, leads to the silicon anodes swelling and expanding, causing them to break quickly and short circuit the battery.

This has been a problem for a long time, and several routes have been offered (mostly by coating them), but the choice of using silicon nanoparticles offers a way to circumvent the traditional challenges posed by silicon anodes. This is because the electrodes are porous enough to cope with the volumetric expansion of the anode during use.

Because these batteries are still in development and only set for mass production in 2024 and commercial use in 2025, there is currently not much data in the way of charging and range. The utilization of the silicon nanoparticle anode, however, is expected to produce an EV battery with an energy density that is 20% greater than the EV Li–ion technologies used today.

As the silicon nanoparticle enhanced battery matures further and improves on its current state, it’s thought that the energy density improvements could be up to 40% greater than graphite–based Li–ion batteries.

While other cars are going to be on the road first, this is likely to be the first global development and market adoption of both nanomaterial–enhanced EV batteries and silicon–based anodes on a large scale. Given the competitive nature of the automotive industry, if a company such as Mercedes is putting so much trust in nanomaterial–enhanced batteries, then it is likely to open the door to more global automotive companies making the move towards nanomaterial–enhanced EV batteries to keep up in terms of performance.

Looking towards the future

The announcements from both the GAC Group and Mercedes have a huge significance in terms of nanomaterial batteries going forward. For years, there has been a struggle to get the likes of graphene or silicon into functional and high–end battery systems, and now that nano–enhanced batteries are going to be used on the road in everyday vehicles, it marks a turning point for nanotechnology in EV batteries.

The more companies adopt these batteries for their EVs, the better they are going to get and that could help to disrupt the status quo that has existed in the battery world for a long time.

While the initial announcement from the GAC Group was the first example of nanotechnology use in EV batteries, the Mercedes announcement certainly carries more significance because we’re talking about cars that could be on the roads around the world, not just in China. So, for global significance, having a huge automotive player like Mercedes adopting nanomaterial batteries for their new EVs sets a precedence for the future of nanomaterials in EV batteries.

Given the adoption of nanomaterials within the automotive sector (not just in batteries) and the challenges of more traditional materials, if the nano–enhanced batteries function well in the coming years in both the Aion V and Mercedes’ G–Class vehicles, then it’s likely that we are going to see more and more nano–enhanced batteries being used in everyday vehicles.

The tests to date have shown good results and promise for wide scale use, and perhaps the only thing that could stunt the use of nano–enhanced batteries down the line is if they don’t exemplify a high degree of long–term stability or safety when used in everyday life ― but we won’t know this for many years.

This article was originally published on EE Times.

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