A big issue with today's electric vehicles (EVs) is that their batteries are heavy. Obviously, this has a number of downsides, including lowered energy efficiency and more wear and tear on roads, tyres and brakes, for example.
Researchers are working on improving that situation, with one approach being to make the battery a structural component of EVs - like the BYD SEAL sold in New Zealand (review coming soon).
A group of researchers at the Chalmers University of Technology in Göteborg, Sweden, have created a carbon fibre composite battery, for "massless energy storage"; the battery acts as structural member that is as stiff as aluminium, and energy-dense enough for commercial applications, the researchers say.
In practical terms, the researchers envisage this could bring us EVs with a 70% increase in driving range, on a single charge. It's not just EVs that stand to benefit from structural batteries: they could halve the weight of laptops, and enable credit-card slim smartphones, the researchers say.
The Chalmers uni team is led by professor Leif Asp, and comprise Richa Chaudhary Johanna Xu, and Zhenyuan Xia. They have been working on how stiff and strong carbon fibres can store electricity chemically, functioning as electrodes in lithium-ion batteries since 2018.
Now their work has produced a battery with 30 Watt-hours per kilogram energy storage. This is lower than what comparable lithium-ion batteries today can manage, but if the carbon-fibre units can be structural and weigh far less, they will reduce the overall energy usage of EVs, for example.
Video from 2021 on structural battery research.
"Investing in light and energy-efficient vehicles is a matter of course if we are to economise on energy and think about future generations. We have made calculations on electric cars that show that they could drive for up to 70% longer than today if they had competitive structural batteries," research leader Leif Asp, who is a professor at the Department of Industrial and Materials Science at Chalmers said.
With an elastic modulus from 25 to 70 gigapascal, a measure of stiffness, the battery material can carry load as well as aluminium, the researchers said.
"In terms of multifunctional properties, the new battery is twice as good as its predecessor – and actually the best ever made in the world," Asp, who has been researching structural batteries since 2007, said.
One important feature of the new battery tech is that it doesn't use "conflict minerals" like cobalt or manganese.
Here's how the researchers describe it:
"The developed battery concept is based on a composite material and has carbon fibre as both the positive and negative electrodes – where the positive electrode is coated with lithium iron phosphate. When the previous battery concept was presented, the core of the positive electrode was made of an aluminium foil.
The carbon fibre used in the electrode material is multifunctional. In the anode it acts as a reinforcement, as well as an electrical collector and active material. In the cathode it acts as a reinforcement, current collector, and as a scaffolding for the lithium to build on. Since the carbon fibre conducts the electron current, the need for current collectors made of copper or aluminium (for example), is reduced, which reduces the overall weight even further.
In the battery, the lithium ions are transported between the battery terminals through a semi-solid electrolyte, instead of a liquid one, which is challenging when it comes to getting high power and for this more research is needed. At the same time, the design contributes to increased safety in the battery cell, through reduced risk of fire."
Plenty of engineering is required still before the battery tech can be commercialised and mass-manufactured, and the Swedish university has set up the Sinonus venture company for the purpose.
Update Professor Leif Asp has provided a further clarification on how the weight savings are achieved.
"The potential mass savings are realised on the systems level. That is, by replacing monofunctional components (ie. a structural part and a battery) with a multifunctional material based component.
In this way reduced weight results if the mass of the multifunctional material component is less than the sum of the mass of the two monofunctional components," Asp said.
He referred to prior research from the KTH Royal Institute of Technology on the topic, and some earlier work from the United States Army Laboratory Research that illustrates the principle for the Tesla Roadster.
Asp said the examples show that even with moderate electrical efficiency of say 50 per cent of the monofunctional device, it is possible to achieve weight savings if the structure has a structural efficiency of 50 per cent or more:
"Please note that we need to further increase the multifunctional properties (i.e. energy density, power density, stiffness and strength) to introduce these in to propulsion systems for e-vehicles, Asp added.
89 Comments
That'd be interesting with the sheer acceleration they could get so quickly but there'd be some intricacies there for sure. In an ICE when the throttle gets released the bike will cruise or slow at a gradual rate, but they'd need to tailor the power on e-motorbikes to taper off in such a a way as well, lest someone ease of the throttle too hard on a corner and have a sudden drop in power and traction.
....and it will probably be twice the price. So, it's great that they re trying to make EVs work, but if this makes them more expensive, then less will sell. It also see a huge part of the story missing here. Charging time. Unless it gets to be less than 10 minutes for a full charge (equivalent of filling with gas, diesel or hydrogen), then there will only be a few takers.
Exactly. This technology is not working, and will never work unless while it provides a worse outcome than the incumbent. Currently EVs provide a worse outcome as a result, of a) range problems, b) charging time, c) towing ability, d) price, e) resale value. amongst others.
EV range is better than ICE range - I start everyday with 500km range. Maybe twice per year I need to go to a fast charger when on a long trip. So charging "time" for EVs is also much less overall than visiting a petrol station every week.
I also make my own fuel using sunshine.
Why, you wouldn't listen anyway.
Meanwhile I'm just over two years of daily driving an EV, including several Auckland to wellington trips and really don't have issues with range or charging.
I've never towed anything with any of my personal vehicles so can't comment from my own experience, but I can say that the gentleman at the the local gliding club I'm thinking of joining prefers to use their Ioniq 5 to tow the glider to events and back from outlandings because the smooth torque from 0 rpm makes them ideal for towing.
Local gliding club being the key. Local. Try towing long distance and hanging around to charge it up every 100-150kms. This whole EV thing is very much like IT. Everyone is working with a different technology, hardly anything works properly, your technology is obsolete as soon as something shiny and new comes along. Basically a mess. Same as EV industry.
When someone announces they have a lab finding that may, one day, lead to something better, it doesn't make everyones Teslas obsolete.
Just as the actually-available-in-the-real-world 5L/100km small turbo engines in family wagons didn't make anyones ICE cars obsolete. Still plenty of 4.0 straight sixes on the road.
I've never heard a Telsa owner complaining that their car 'never works properly'.
It really is - this is proof that we can reduce the energy required for economic gains and we're only scratching the surface.
A great example of our power as a species to get more for less energy output, and at the same time removing need for conflict materials. The power of ingenuity will drive us so much further than nay sayers believe.
Your move PDK.
And then the materials going into said carbon fibre and the energy to charge it for the lifecycle plus disposal, will be less environmental impact than the alternative materials going into internal combustion engine, fuel for lifecycle plus disposal.
And to pre-empt it, no, there is no good faith argument to use neither of these because that would mean de-industrialising and moving back to less efficient forms of transport for passengers and goods (which would take us to the supposed end of energy which is touted here).
It's wild that the comment sections on anything electrified is met with "this won't work because X specific use case" or "yeah but did you know it takes materials to make electrical components" and no examination of the opportunity cost being oil and gas, which is far worse over the lifecycle (if you look beyond just building and disposing of a vehicle, because it's apparent nobody wants to examine the tens or hundreds of thousands of litres of petroleum products required to operate said vehicles).
Be forward looking team, have curiosity and be interested in opportunity, otherwise you may end up stuck in your old ways waving your fist at innovators and youthful bright minds and it will only be at your expense.
Lol, except as pointed out down below, 30Wh per kg means a two ton battery pack to replace the existing (500kg?)battery in my Tesla, which happens to weigh less than two tons as it is.
So at this stage they have demonstrated absolutely nothing of value and the predictions of extending EV range by 70% with this technology is nothing but unbridled techno-hopium and spin to get investors on board.
A bit like the years of "almost there" on cold fusion, solid state batteries and the second coming of Christ.
This is the first iteration, expect improvements as we did with the battery structures we see in your tesla.
Further, that 2 ton weight would be including the structure, which already exists and has weight, so the weight would not be expected to increase by 1.5 tons as the existing battery in your tesla would no longer be present.
The breakdown of weight is of both structure and battery, whereas your example only lists the weight of the battery component.
The breakdown of weight is of both structure and battery, whereas your example only lists the weight of the battery component.
Nope, actually its the other way round. That 30Wh per kg is for a bare cell, the 480kg ish of a Tesla battery pack is ~260kgs of cells, plus thermal management systems, battery management system, insulation and protective casing, and high voltage safety systems. All of which you need to add on top of your bare cells. Until these CF cells hit 200Wh per kg or more at the cell level they aren't going to make an improvement over current li-ion batteries.
battery capacity doubles every 2 years? I don't think so.
https://en.wikipedia.org/wiki/Moore%27s_law#/media/File:Moore's_Law_Tra…
vs lithium 'doubled in a decade'
https://www.researchgate.net/figure/Battery-Energy-Density-Trends-Impro…
How do my links support that position?
If the position is that Moores law is in effect for lithium battery energy density, then energy density would need to double every year or two[1]. I showed that it does not, it follows a much slower improvement rate, taking 10 years to double.
[1]Moore originally postulated a doubling of transistor count every year, but a decade later revised that to every two years.
I don't recall carbon fibre being cheap. Usually reserved for formula 1 cars and america cup boats? Are there any mainstream vehicles with significant carbon fibre?
The trend to put bit of plastic detailing in a 'sports' car with pretend carbon fibre print on it doesn't count.
"a passenger module of high strength, ultra-lightweight carbon fibre reinforced polymer adhered to an aluminium chassis"
cool, thanks. The i3 at 1195kg is fractionally lighter than my ICE family wagon.
EV batteries are already pretty non repairable, at best you can swap cells/blades/pouches out, but some are filled with a foam that's basically impossible to remove. Check out the Munro live teardown of a Tesla structural pack. Best bet is those will just get swapped out, and ground up for chemical recovery.
yeah but at least when it's in protected bunker chamber in the middle of the car it's much less likely to get damaged unless the car is totaled. And if you have any failures as you say you can swap cells in and out.
If it's integrated into the structural members though, how to you swap that out after a minor prang or if individual cells are failing?
the engine might bolt in, as do traditional EV batteries ala Leaf / Tesla, but the frame certainly doesn't bolt in.
Though it only took them two days to integrate a new bit of carbon fibre into the NZ americas cup boat, so maybe rebonding carbon fibre isn't especially hard compared to welding steel.
It's early days for battery tech - rapidly moving out of the Stone Age era however...........
IMHP the economic model for EV's is more akin to iPads than ICE vehicles - once they get to an economic life of 5 - 7 years like them we will all be in!
Lower cost, more range, faster charging - things will look very different by 2030.
Just accept if you buy now what you have will be junk by year 7 due to technical obsolescence.
No, not junk,
Just like the 10yo computer in the corner, it's probably going to still be capable of doing exactly what it was when purchased, it just doesn't have the flashy lights and doodads of newer models.
It's not like in 7 years I'm suddenly going to be able to drive Auckland to wellington without a lunch stop and a couple of toilet breaks.
https://www.strategyand.pwc.com/de/en/industries/automotive/electric-ve…
Looking at the sum of sales in all 21 analyzed markets, the electrified vehicle market share reached a new height. More than one in three vehicles (37%) sold in these markets in the second quarter of 2024 were BEVs, PHEVs or hybrids, up from 30% in the equivalent quarter in 2023. Meanwhile, total EV sales grew by 21% in Q2 2024 vs. Q2 2023, while ICE sales fell by 9% in the same period.
But what would PWC know..
Yeah, thats a thing of the past these days, most new sites are 3+ chargers capable of charging 6+ cars at once.
Let's look at chargenets latest 4 new sites/upgrades
Queenstown central, 3 x 150kW chargers, each capable of charging 2 vehicles at once.
Tauriko, at total of 15plugs, 10 cars can charge at once.
Motueka new world, they upgraded to 2 x 150kw chargers, so 4 cars can charge at once. And there is another charger across the road at the warehouse.
Bethlehem town centre, 3 x150kW chargers, so up to 6 cars charging at once.
Single chargers still the norm in northland. https://charge.net.nz/map/ Good things take time.
Yes, but then again you are pretty unlucky to find someone using one, and to have someone else waiting.
And from Whangerei where there are multiple chargers a decent EV will get to Ahipara, and back down to waipapa/kerikeri on a charge, passing at least 2 50 kW chargers on the way.
The only time you are likely to have an issue in a decent EV is holiday weekends.
The US attempts to re-industrialise by building batteries for EVs, while using economic coercion to disrupt Chinese supply chains.
But batteries require graphite, and the US is 100% import dependent. China provides 67% of global supplies and 90% of graphite processing. China recently also produced a purification technology to achieve 99.99% pure graphite.
Last year, China imposed restrictions on graphite exports in response to US economic coercion. China can recreate and repatriate its supply chains. The US cannot.
It's like EU sanctions on Russia. Russia can diversify away from the EU, but the EU cannot diversify away from Russia. The solution usually becomes to buy the same materials and products (gas, titanium etc) through a third party at a much higher cost.
Seems everyone is overlooking a rather core consideration: "the battery acts as structural member".
The Britten V1000 motorcycle made various essential components of a motorcycle part of the structure (frame) to save weight. Did every motorcycle manufacturer - or even a quarter - follow Britten's lead? Nope.
I see the same old arguments cropping up every time EVs are mentioned - "it won't work for my specific use case, therefore it is junk."
My in-laws just sold their 2012 Nissan Leaf (possibly the worst EV example commonly available) because its range was down to 40-odd km, which didn't work for them anymore. However, they quickly found a willing buyer for whom that was perfect for their daily commute. I don't know what the odo reading was but it'd be well over 100,000km by now. I wish I'd know they were selling it, we would have bought it back from them - yes, we sold it to them in 2019 - so we could use it around the paddocks. A full charge would last us weeks since all the trips would be low speed and short distances, which is where EVs excel.
Just imagine sitting in big city rush hour traffic where even 30% of the fleet around you isn't idling along, generating air and noise pollution. Imagine the price of fuel after a 30% drop in demand.
Think wider than your own situation - hundreds of thousands of NZ families could easily get by with an EV but many people exaggerate their requirements for vehicles. No it won't get from Auckland to Wellington on a single charge, but how often do people do that? Twice a year? So why not have an EV for the 99%+ of the time you spend pootling round the suburbs averaging 35km/h on a good day, then hire the latest and greatest car for the twice-yearly trip to see Grandma/Uncle Bob? Let Avis/Hertz/Budget pay for the upkeep of that. Same goes for the fractions of a time each year people need to tow something over 750kg.
I'm sure plenty are reading this thinking "yeah but I need to..." but again, that's you, not the majority of the population. Then there's the "they're all so expensive..." argument. So are new ICEVs, but someone has to buy them for them to eventually become cheaper used vehicles. Even if you're a died-in-the-wool, Bathurst-is-my-church, from-my-cold-dead-hands ICEV fan (which I am) you can still be encouraging of the improving EV market, even if it's for your own selfish desires. I personally would love a quieter environment with cleaner air every time I'm sentenced to going into a large city, and maybe even cheaper fuel for all my vehicles.
But if you're packing less than 200kW that old Leaf is still going to smash you at the 0-50km/h traffic light drag.
Sheesh. Nobody has bothered to do the maths on this.
So this battery can provide 30Wh of energy from 1kg of 'structure'.
My current EV has a 60kWh battery. The battery is a half ton roughly, the total mass of the car is 2 ton roughly.
So to get the equivalent energy from this 'structural' battery you would need 2000kg of 'structural battery'. 2 tons of 'structural battery', then add in the weight of all the other bits that can't be made from structural battery (windows, wire looms, motors, inverters, upholstery, airbags, seatbelts, HVAC, wheels, tyres, braking systems).
So then you get a car that's likely over 3 tons pretending it does a better job than a 2 ton car.
Given weight is the enemy of vehicular fun, I want to see what someone like Lotus (motto: add lightness) will do with the technology if it becomes available.
The market just might be hankering for a light, communicative, fun electric car. In an ideal world it would drive like a 21st century Alfasud - but be built by a Japanese maker so it didn't rust or leak.
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