Cars and planes whose body is the battery

How far are we from cars and planes whose body stores their energy?

A structural battery is a carbon-fibre composite that stores electrical energy while it carries loads. Chalmers University of Technology has reported laboratory structural battery composites with 30 Wh/kg and a stiffness above 76 GPa along the fibres. No complete car body or aircraft structure that also serves as the main battery pack has been shown in the sources reviewed. The main gaps are whole-product mass saving, damage and repair, safety in a crash or fire, and a route to certification.

AI illustration · Illustrative scene, not a photograph of the specific device or experiment.
WHERE WE AREScience demonstrated

Far away. The science works, but nobody has built a working system yet.

Cells that use carbon-fibre electrodes as both the energy store and the reinforcement have been made and tested in laboratories, and the results are published in peer-reviewed journals. The sources opened show laboratory cells and material samples, not a prototype vehicle or aircraft component. Chalmers says a lot of engineering work remains before cells move from small-scale lab production to large-scale production, so the stage is science-demonstrated rather than engineering-prototype.

The tech tree

Everything recorded on Vrulum that this future needs, oldest foundations at the top and the goal at the bottom. Lines show what each step requires.

What it takes: Cars and planes whose body is the battery Unlocked Being researched Locked
  1. 1859PowerLead-acid batteriesCommercial Unlocked.
  1. 1976PowerLithium-ion batteriesCommercialRequires: Lead-acid batteries. Unlocked.
  1. 2016Solid-state batteriesResearch and prototypesRequires: Lithium-ion batteries. Being researched.
  1. 2020Electric aircraftPilot and early commercialRequires: Solid-state batteries. Unlocked.
  2. 2024Structural batteriesLab demonstration Being researched.
  1. 2024Carbon-fibre structural cell made and tested in the laboratoryDone Unlocked.
  2. 2025Full-cell model checked against test dataDone Unlocked.
  3. 2025Higher figures reported but not yet publishedIn progress Being researched.
  4. 2025Scaling from lab cells to productionIn progress Being researched.
  5. Date not recordedLoad-bearing battery in a road vehicle body or aircraft structureNot started Locked.
  6. Date not recordedDamage, repair, safety and certification routeNot started Locked.
  1. GoalCars and planes whose body is the batteryGoalRequires: Structural batteries, Electric aircraft, Carbon-fibre structural cell made and tested in the laboratory, Higher figures reported but not yet published, Full-cell model checked against test data, Scaling from lab cells to production, Load-bearing battery in a road vehicle body or aircraft structure, Damage, repair, safety and certification route. Locked.

The road so far

2 of 6 steps done, 2 in progress.

  1. Done · 2024Carbon-fibre structural cell made and tested in the laboratory

    Chalmers researchers reported a structural battery composite in which carbon fibres act as both electrodes and reinforcement. The abstract reports 30 Wh/kg, a modulus above 76 GPa parallel to the fibres, and up to 1,000 cycles at about 100% Coulombic efficiency. The abstract does not state the test rate, or whether the energy density is per cell or per composite. Chalmers's 2024 explainer gives the stiffness as 70 GPa, below the paper's figure, and the paper's figure is used here. [1]

  2. In progress · 24 Jun 2025Higher figures reported but not yet published

    Chalmers's June 2025 news update says an ongoing study has produced structural battery composites with over 60 Wh/kg and an elastic modulus of over 100 GPa. The update does not name a paper or dataset for these figures, so they remain reported but unverified. [4]

  3. Done · 2025Full-cell model checked against test data

    A 2025 study built a fully coupled electrochemical and mechanical model of a structural battery full cell in which carbon fibres form the negative electrode. The authors report that the model reproduces the general trend of the measured voltage profiles across a range of charge rates, without claiming an exact match. It is modelling evidence rather than a demonstrated product. [2]

  4. In progress · 24 Jun 2025Scaling from lab cells to production

    Chalmers says a lot of engineering work remains before cells move from small-scale lab production to large-scale production. Its June 2025 update says a new competence centre, MAXBATT, will focus on scaling up the technology and training a workforce for battery factories. Chalmers gives no commercial timeline. [3][4]

  5. Not startedLoad-bearing battery in a road vehicle body or aircraft structure

    No complete vehicle or aircraft has been shown in which the load-bearing structure is also the main battery pack. Leif Asp, of Chalmers, suggests thinner phones and lighter laptops could come first, and says the transport industry would need large investments. The sources reviewed give no date. [3]

  6. Not startedDamage, repair, safety and certification route

    The sources reviewed do not show how a damaged load-bearing cell would be detected, isolated or repaired, how it would behave in a crash, puncture or fire, or how aircraft or road-vehicle regulators would approve it. These questions are open.

Why it matters

If a structure could store energy as well as carry load, a vehicle or aircraft could in principle avoid carrying some separate battery mass. That would matter most for aircraft, where every kilogram counts. The same idea could also reach phones and laptops first, which would show how the material behaves in service before it is used in larger and more heavily regulated machines.

What stands in the way

  • The energy and stiffness figures come from laboratory cells and material samples. No complete vehicle or aircraft whose load-bearing structure is also its main battery has been shown.
  • Energy density per kilogram does not show that a finished product is lighter. Protection, wiring, power electronics, support structure and repair provisions all add mass, and the whole-product result is not known.
  • Chalmers says high power is challenging with the semi-solid electrolyte used in its 2024 design, and that more research is needed.
  • Ageing, fatigue, impact and damage while the cell is charged and discharged are not addressed in the sources reviewed.
  • The sources reviewed do not describe how a damaged load-bearing cell would be detected, isolated or repaired, or how it would behave in a crash, puncture or fire.
  • No certification route for load-bearing batteries in aircraft or road vehicles was identified in the sources reviewed.
  • Chalmers says a lot of engineering work remains before large-scale production (2024 explainer), and its 2025 update gives no commercial timeline.

Signals to watch

  • A published paper or dataset behind the over 60 Wh/kg and over 100 GPa figures, stating the mass basis, test rate and cycling conditions.
  • A full-size panel or body part with structural battery cells, tested for fatigue, impact and ageing while it is charged and discharged.
  • Independent measurements of structural battery energy density on a stated mass basis, from a group other than the original authors.
  • Published safety tests on a damaged structural cell, including puncture and thermal runaway.
  • A product that uses structural batteries in electronics, such as phone or laptop casings, reporting field use.
  • A certification body or standard that covers load-bearing batteries in aircraft or road vehicles.
  • Announcements from Sinonus AB, a Chalmers Ventures company that Chalmers's September 2024 explainer names as a route to market.

Sources

  1. peer reviewed paper
    Unveiling the Multifunctional Carbon Fiber Structural Battery
    Richa Chaudhary, Johanna Xu, Zhenyuan Xia et al.. Advanced Materials (Wiley), 10 Sept 2024.
  2. peer reviewed paper
    Electro-chemo-mechanical modelling of structural battery composite full cells
    Carl Larsson, Fredrik Larsson, Johanna Xu et al.. npj Computational Materials (Nature Portfolio), 19 May 2025.
  3. university press release
    World's strongest battery paves way for light, energy-efficient vehicles
    Chalmers University of Technology, 19 Sept 2024.
  4. university press release
    Structural Batteries from Chalmers Highlighted by the World Economic Forum
    Chalmers University of Technology, 24 Jun 2025.

Last reviewed 21 Oct 2026.