Battery technology and electric vehicles: forward-looking statements

Jon Lawson

How will battery technology impact other aspects of vehicle design? Dr Luca Castignani shares his thoughts

Hexagon’s manufacturing division has some 8,000 employees spread across 32 countries. The company is involved in all aspects of vehicle development. Here Dr Luca Castignani, global automotive industry director, answers our questions.

Q. Are there enough raw materials?

Material shortage is a large factor impacting vehicle production and manufacturing – not only is there a lack of raw materials, but there are many concerns over the economic and social cost of sourcing enough for use. Shortages of nickel and cobalt, for example, could delay production and lead to overexploitation of natural resources in the developing world.

The future of electric vehicle battery production needs to meet the demands of environmentally conscious consumers – whether that is through enhanced traceability over materials, or the commercialisation of new battery technology with R&D that reduces dependency on exotic materials.

Q. What about battery recycling?

Battery recycling will definitely be a part of the journey towards more sustainable electric vehicles. Amongst OEMs, there has been a lot of talk about how this could take place. For example, Renault is proposing to reuse batteries for non-automotive purposes. After a battery is no longer running efficiently enough for a car, it still holds a lot of value for storing energy for domestic use, such as when generated from solar power.

The key to battery recycling is for batteries to be optimised for recyclability at the design stage, which requires processes such as design, engineering and manufacturing to be ‘joined up’ and virtualised. Linking together fragmented manufacturing processes enables car makers to see how even micromaterials can be optimised for recyclability before the first prototype rolls off the production line.

Q. What about super-capacitors?

Super-capacitors are great at delivering high power for a short amount of time (hence they can store little energy). They are the perfect companions for typical batteries that show optimal performance when the power drainage is medium to moderate.

Q. What is the future of battery cooling?

I believe batteries will be cooled using liquid as they are today – but there may still be changes to how this is designed. Currently, there are two methods: cooling under the battery module or running liquid in between the cells.

Cooling will also depend on the battery. Tesla, for example, runs a cooling tube around cylindrical battery cells, allowing it to cool much faster. On the other hand, pouched cells are able to be lined up compactly in the battery, taking up less space overall. Thermal design remains a hugely important topic for EV development and finding the most efficient and safe solution requires a system-level approach to engineering, and skills that are in short supply at the moment.

Q. Should the battery be removable?

Personally, I think removable batteries are the right direction for development to go. Batteries are inherently designed as modules, and in the future, we will be able to buy a car with more modules than the 6 found in vehicles today.

This ensures its longevity – if anything goes wrong with one of the modules, it can easily be removed and replaced without having to remove perfectly functioning parts.

Q. Will we see more ’skateboard’ chassis?

In my opinion this would be the right approach. In the last decade, we have seen disruptions in powertrains and batteries. We’ll expect battery integration inside the vehicle structure next – but that’s unlikely to hit the road for another decade.

Q. What about fuel cell use?

Fuel cells are able to recharge much faster than conventional batteries – an advantage for long-range commercial haulage vehicles which require long battery life and short refuelling times during long drives. However, a balance needs to be achieved. Commercial vehicles do not have the market size to achieve economies of scale. Automotive OEMs need to not only consider fuel cells for long-range vehicles but also for last-mile delivery fleets, which have very similar needs, benefits and patterns of use.

Q. How will chassis design adapt?

Everything will be heavily affected. Batteries are the most important component of the EV and affect all of its constituent parts. For example, 80% of braking actions are not done by the brake itself, but through regenerative braking in order to recuperate the lost energy into the vehicle’s battery. This is important because it affects the loads on the braking system, its durability – which will be extended - and its size and weight. Furthermore, as the battery has a very low centre of gravity, this will improve load transfers during turning and braking, making all these manoeuvres more stable.

Automotive OEMs need to take all these interrelated demands of the battery into account – a great challenge due to the fragmented nature of the electric vehicle ecosystem. Processes in the automotive manufacturing chain are traditionally siloed from design to production, but with greater consumer demand for electric vehicles comes great stress on the system.

We at Hexagon recently unveiled a 100% EV, which aims to integrate new product introduction from e-powertrain design to forming, assembly and quality inspection to accelerate the global transition to EVs. The aim is to bring disjointed development processes and disciplines together to address challenges with greater insight and productivity. This will span a range of objectives, from increasing the efficiency and durability of electric powertrains, to optimising manufacturing processes and quality.

Q. How can batteries be made lighter?

Battery lightweighting is important, but it’s an effort with diminishing returns. Resources have been used to develop lighter battery trays or clamps, but over 80% of battery weight is in the cell itself. Even if the weight of the battery tray is reduced by 30%, it will only impact 6% of the overall weight of the battery – and only 2% of the entire vehicle.

In my opinion, our next efforts need to be focused on pouch cells. Although they come with their own challenges, they are lighter because they don’t have the outer metal case. Furthermore, they can be stacked more densely and, as a result, give better range with the same occupied volume.

Q. How can vehicles in general be made lighter?

In every new generation of vehicles, models get heavier because we want more features and capabilities in a modern car. The only way to get away from this spiralling black hole is to optimise the vehicle as a whole, rather than as a sum of parts. Examples of this approach are becoming more frequent: the Porsche Taycan, for example, shares the same cooling circuit between the battery and the motors, and the battery can act as a heat sink for the motor. Also, the battery benefits because it gets warmed by the motor in the optimal working range (20-30º Celsius).

Use of advanced materials is also interesting, especially when they can be shaped in complex forms that would otherwise require multiple parts to be then connected during the assembly phase.

Composite materials are another important part of trying to make EVs lighter and therefore improve their range. For this to be effective, it’s important that data is effectively managed so that vital information on materials is not lost following testing between the various teams, and that the materials engineering process is effectively co-ordinated with the rest of the design and production and does not operate as a silo.

Q. What alternatives to fossil fuels are there?

There is no clear path to electrification, and there are still many hurdles we are yet to face – the largest of which is infrastructure. For example, how will we produce all the electricity needed to power electric vehicles, and how will we ensure consumers will be able to access charging stations across the world?

For global adoption, electric vehicles must be better than conventional ones in every single way. Infrastructure is only one barrier we need to address – others include safety, manufacturing, quality inspection and many others. While consumer demand grows, OEMs not only have to deal with these demands during development, but also the conflicting needs of increasing profits while reducing prices.

In this regard, Computer Aided Engineering and virtual manufacturing software is driving this effort to deliver more efficient and consumer-friendly vehicles. Through digital integration of R&D and manufacturing, Hexagon is working alongside automotive OEMs and their suppliers to develop and test new approaches and components from a system point of view. EVs really demand a system or ‘global’ optimisation approach and rely extensively on multi-disciplinary engineers and new skills to achieve huge progress so quickly.

 It’s challenging, to say the least, to maintain ICE innovation and supply chains while simultaneously investing in new EV challenges. Biofuels are seen as an alternative option, but it may well be too late for widespread implementation. Governments are already investing in electrification, which is seen as the step beyond. With low oil prices and no subsidisation, biofuels will not be able to take off. Until full electrification, internal combustion engines will act as our safety net, and it will take time before we are able to confidently stop relying on them.

Q. Can quality be improved across the board?

Quality has to become part of the design process because ultimately, it is the outcome of a robust design. Quality means designing a system that works as expected in reality, not just in theory. To achieve that, we have to stop thinking that quality is just a measure of how good the production stage is. Instead, production measures and consumer usage have to circle back to the designer so they can apply real-life conditions from the beginning.

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