Are Structural Batteries the Solution to Electric Aircraft?

Electric aircraft have one big enemy: weight. Batteries are heavy, wings have limits, and gravity is annoyingly consistent.
If you’ve ever watched a sleek electric car glide by and wondered, “Why can’t we just scale that up to airplanes?”, the short
answer is: because an aircraft can’t drag a gigantic battery pack through the sky and still fly efficiently or safely.

That’s where structural batteries enter the chat. Instead of treating the battery as a separate, bulky box,
structural battery technology turns parts of the aircraft itselflike the wings, fuselage, or internal framesinto energy-storing,
load-bearing components. Think of it as giving the airplane’s skeleton a secret superpower: it both holds the plane together
and powers it at the same time. Researchers sometimes call this idea “massless energy storage”, because the weight of
the battery is effectively “hidden” in structure that would have to exist anyway.

So, are structural batteries the long-awaited solution that will finally make fully electric aircraft mainstream? Let’s break
down what they are, what they can actually do today, and whether they’re ready to carry you (and your carry-on) across the sky.

What Exactly Is a Structural Battery?

A structural battery is a material system that combines two jobs:

• It behaves like a battery, storing and releasing electrical energy.
• It behaves like a structural component, carrying mechanical loads like a wing spar or fuselage panel.

Instead of putting conventional lithium-ion cells into a housing and then bolting that housing into the airframe,
a structural battery merges the energy storage directly into the composite material. In practice, that often means:

• Carbon fiber that doubles as an electrical electrode and a strong reinforcement material.
• A solid polymer electrolyte that both conducts ions and binds the composite together.
• Layered laminates or sandwich panels that look like advanced carbon-fiber parts but quietly store energy inside.

In other words, the “bones” of the airplane become part of its “battery pack.” No bulky modules. No separate enclosures. Just
multifunctional structures that hold the plane together while powering it.

Why Electric Aircraft Need a Different Kind of Battery

For cars, today’s lithium-ion batteries are heavy but acceptable. You can add more cells, tweak the aerodynamics a bit, and
still end up with a practical EV. Aircraft are a very different story:

• Every extra kilogram reduces range, payload, or both.
• Aircraft must meet strict safety margins for structure and performance.
• Power demand during takeoff and climb is intense, especially for eVTOL aircraft and regional electric planes.

Reviews of battery technology for aviation consistently show that electric aircraft demand higher specific energy
(Wh/kg), high power, long cycle life, and excellent safetystandards that push beyond what many EV-grade cells can handle,
particularly for vertical takeoff or commuter aircraft.

Structural batteries offer a clever way to improve the system-level energy density, even if the battery material itself
isn’t dramatically better than conventional cells. By making the structure and battery one and the same, you remove redundant weight.

How Structural Batteries Could Transform Electric Aircraft

“Massless” Energy Storage and Weight Savings

With structural batteries, weight that used to be “just structure” now also stores energy. Studies and concept designs suggest
that, depending on the design, structural battery composites could cut effective battery system mass significantly and reduce
overall aircraft weight in hybrid or fully electric configurations.

For ground vehicles, some analyses suggest that simply replacing the roof of an EV with a structural battery could reduce total
weight by up to around 20%, opening the door to more range or smaller packs. While aircraft are more complex, the same logic applies:
use the wings, fuselage shells, and interior structures as part of the energy storage system, and suddenly the “battery penalty”
is less painful.

Design Freedom: Turning Wings and Fuselages into Power Plants

Electric aircraft designers already love composite materials because they’re light and strong. Structural battery composites push
that idea further by allowing:

• Distributed storage along wings and fuselage, reducing the need for concentrated battery bays.
• Shorter cable runs, since power is generated closer to motors and systems, potentially cutting wiring weight.
• New architectures, from ultra-slim flying wings to blended-body aircraft where large surface areas double as giant batteries.

For small drones and urban air mobility vehicles, this could translate into more compact designs, quieter operation, or extra
payload capacitywithout swapping to exotic fuels.

Safety and Crashworthiness Potential

Regular lithium-ion packs can become a single failure hotspot in a crash. Structural batteries, if carefully designed, could
distribute energy storage through the airframe and be combined with robust crash structures, solid-state electrolytes, and
built-in thermal protection. Researchers are actively exploring how to ensure these multifunctional components deform in a
controlled way while keeping passengers safe and minimizing fire risk.

Where the Technology Stands Today

Now for the reality check: structural batteries today are impressivebut not magical.

Typical structural battery composites in the lab currently achieve roughly 30–90 Wh/kg of specific
energy, while offering stiffness comparable to lightweight metals like aluminum and tensile strengths in the hundreds of megapascals.
Conventional aerospace-grade lithium-ion cells, by contrast, can exceed 200 Wh/kg at the cell level.

That sounds like a big gap, but you also need to consider the whole system. Regular batteries require housings, mounts,
cooling structures, and wiring, all of which add weight and don’t store energy. Structural batteries remove a lot of that overhead
by integrating energy into components that must exist anyway.

One review estimates that for a small all-electric aircraft, a structural battery would need at least about 51.8 Wh/kg
to be viable at the system level. Some prototypes are already in that ballpark, though they still need further improvement in cycle
life, damage tolerance, and manufacturability before they’re flight-ready.

Meanwhile, NASA and other agencies are pushing advanced solid-state chemistriessuch as sulfur-selenium systemswith specific
energies around 500 Wh/kg in the lab. Those are not structural batteries yet, but combining such high-energy
chemistries with structural designs is an obvious long-term goal.

Key Challenges Blocking Structural Battery Aircraft

Balancing Strength and Energy Density

Structural batteries walk a tightrope. To be a good structural material, you want high stiffness, strength, and toughness.
To be a good battery, you want maximum ion transport, active material content, and interface surface area. Those needs don’t
always play nicely together.

Load-bearing components for aircraft can have mechanical properties two to three orders of magnitude higher than those of
typical battery materials. Making a material that satisfies both mechanical and electrochemical requirementswithout being
overly heavy or fragileis one of the biggest design puzzles in this field.

Durability, Fatigue, and Maintenance

Aircraft structures must endure:

• Thousands of flight cycles.
• Thermal swings from hot tarmac to cold, high-altitude air.
• Vibration, gust loads, and occasional hard landings.

Now imagine that every one of those events is also stressing your battery. Cracks, delamination, or micro-damage that used to be
“just” structural issues might now affect the battery’s performance, safety, or both. That means new inspection tools
(for example, advanced ultrasonic or embedded sensing) and more sophisticated health-monitoring algorithms are needed to track
both structural integrity and state of charge in the same material.

Certification and Safety Regulations

Aviation regulators are still figuring out how to certify conventional battery systems for eVTOL and hybrid aircraft.
Structural batteries add a new layer of complexity: if the wing is also a battery, how do you certify its crash performance,
fire resistance, lightning protection, and long-term reliability as a single unit?

This will require new test standards, new simulation methods, and close collaboration between airframers, materials scientists,
and regulators. In other words: it’s not just a materials problem; it’s a system-level and regulatory problem too.

Manufacturing and Cost

Finally, structural batteries have to be manufacturable at scale. High-precision composite layups, controlled curing, and careful
alignment of electrodes and electrolytes all add complexity to the production line. For mass adoption, manufacturers will need:

• Robust, repeatable fabrication processes for large, battery-integrated structures.
• Repair strategies for panels that are both structural and electrochemical devices.
• Affordable supply chains for specialized materials, from carbon fibers to polymer electrolytes.

Near-Term Use Cases: Where Structural Batteries Make Sense First

While a fully electric, structural-battery-powered transatlantic jet is still science fiction, there are nearer-term applications
where the technology looks promising:

• Small drones and UAVs: These vehicles already use composite airframes and benefit greatly from any weight savings.
  Structural batteries could increase flight time or payload capacity without changing form factor.
• Urban air mobility and eVTOL demonstrators: Early prototypes might use structural batteries for secondary structures
  (like interior panels or fairings) to validate performance before moving to primary load-bearing parts.
• Hybrid-electric regional aircraft: Structural batteries could support part of the energy loadespecially during cruisewhile
  conventional packs handle peak power demands for takeoff and climb.
• Space and high-altitude platforms: NASA and others have already explored structural battery concepts for small satellites
  and high-altitude aircraft, where volume and mass are both at a premium.

These early adopters will provide real-world data to refine materials, manufacturing, and certification pathways for larger, passenger-carrying aircraft.

So… Are Structural Batteries the Solution to Electric Aircraft?

Structural batteries are not a single silver bulletbut they’re one of the most intriguing tools in the toolbox for sustainable aviation.

On the plus side, they:

• Offer “massless” energy storage by merging batteries into structures.
• Improve system-level energy density without waiting for miracle chemistries.
• Open new design possibilities for future aircraft architectures.

On the minus side, they:

• Still lag far behind the cell-level specific energy of the best lithium-ion or next-gen solid-state batteries.
• Face tough challenges in durability, inspection, and repair.
• Need new certification frameworks and manufacturing know-how before widespread deployment.

Realistically, the path forward for electric aircraft will likely combine several technologies: advanced structural batteries,
higher-energy chemistries, optimized aerodynamics, hybrid powertrains, and perhaps hydrogen or sustainable aviation fuels for longer routes.
Structural batteries are a powerful concept, but they’ll be part of a larger ecosystem rather than the lone hero.

In short: structural batteries are a big part of the answer for electric aircraft, especially at small to medium scales,
but they’re not the final chapter. More like an exciting plot twist in an ongoing engineering story.

Practical Experiences and Lessons Around Structural Batteries for Aircraft

While most people don’t have a structural battery in their garage (yet), the experiences coming out of labs, design studies, and
early demonstrators already offer some valuable lessons for anyone watching the future of electric aircraft.

Lesson 1: Start Small and Non-Critical

Teams working on structural batteries for aviation tend to begin with non-critical componentsthink interior panels,
fairings, or secondary structures that don’t carry primary flight loads. These components are perfect “training wheels”:

• They still offer meaningful weight savings when converted to structural batteries.
• They’re easier to certify and test, since failure paths are less catastrophic.
• Engineers can experiment with wiring, health monitoring, and repair techniques without putting the entire airframe at risk.

This staged approach mirrors how composites themselves were introduced in aerospace: first for secondary structures, then progressively
moving into wings and fuselages once confidence and data accumulated.

Lesson 2: Co-Design Is Non-Negotiable

A recurring experience in structural battery projects is that you can’t simply “drop in” a structural battery like a replacement part.
Instead, you need co-design between:

• Aerodynamicists, who care about shape, drag, and lift.
• Structures engineers, who worry about loads, fatigue, and safety margins.
• Battery and materials specialists, who optimize chemistries, interfaces, and thermal behavior.
• Systems engineers, who handle wiring, power management, and fault isolation.

Early prototypes have shown that when these teams collaborate from day one, they can create elegant solutionslike wing skins that
store energy while meeting stiffness and flutter constraints. When they don’t, you get designs that are either great batteries and
poor structures, or fantastic structures with disappointing energy performance.

Lesson 3: Testing and Monitoring Need an Upgrade

One of the most eye-opening experiences has been the realization that traditional non-destructive inspection methods
aren’t always enough. Engineers need to know not only whether a panel is cracked but also what that crack is doing to the local
electrochemistry and safety margins.

This has driven interest in:

• Embedded sensors for strain, temperature, and voltage.
• Advanced ultrasound or resonance techniques that map internal battery structure.
• Digital twins that combine flight loads and charge/discharge history to predict when maintenance is needed.

The takeaway is clear: structural batteries force the industry to think of structure and power as a single, unified system. That’s
exciting, but it also raises the bar for testing and certification.

Lesson 4: Think in Terms of Missions, Not Just Materials

Another practical insight is that structural batteries don’t need to be perfect for every mission to be valuable.
For example, a regional aircraft that flies short, frequent hops might benefit more than a long-range jet because:

• Range requirements are modest, so system-level gains from structural batteries are meaningful.
• Charging and maintenance cycles can be built into tight, predictable schedules.
• Hybrid architectures can use structural batteries for cruise, while conventional packs or turbines handle takeoff.

Similarly, high-altitude, long-endurance drones that stay aloft for days could use structural batteries in their wings to
supplement solar power, storing energy during the day and releasing it at night. In these cases, the mission profile and
operating environment can be tailored to the strengths of structural batteries.

Lesson 5: Expect Hybrids, Not Purity

One of the most realistic “experience-based” conclusions is that we’re not heading toward an all-or-nothing future where aircraft
are either 100% structural battery or 100% conventional cells. Instead, hybrid solutions are likely:

• Primary structures with modest energy storage integrated into them.
• Dedicated battery modules for peak power demands and redundancy.
• Possibly hydrogen or sustainable fuels for longer legs, with structural batteries handling local electrical loads.

This layered approach spreads risk, simplifies certification, and allows each technology to shine where it’s strongest. Structural
batteries don’t have to do everythingthey just have to do enough, in the right places, to tilt the weight-and-range equation in
favor of electric flight.

Put simply, the real-world experience so far suggests that structural batteries are less like a “magic fix” and more like a powerful
design upgrade. They won’t instantly turn every airplane into a flying smartphone battery, but they are steadily changing how engineers
think about where energy lives in an aircraftand that shift alone could be transformative.