Imagine if your car weren’t powered by a conventional battery under the hood but by energy stored in its walls or even its roof? This is a future that Dr. Bhagya Dharmasiri and her colleagues at the Deakin Institute for Frontier Materials have been exploring, bringing load-bearing structures and rechargeable energy storage together to create structural battery composites.

They’re working to embed zinc-based energy storage into carbon fiber structures rather than use the lithium-ion batteries found in many modern electronics. The goal is to make safer, better-performing electric cars, airplanes and more.

Rethinking strategic metals

Lithium and zinc are both critical metals for energy storage, but they have different advantages and risks. Although lithium-ion batteries can deliver a large amount of energy, they also pose a risk of fire or toxic gas release if handled incorrectly. These risks can lead to explosions and fires, as seen in recent years with portable chargers and e-bikes.

There are several approaches to mitigating these risks, including safer electrolytes and improved materials and battery design. Dharmasiri and her colleagues are also researching these areas.

“Lithium remains an important energy-storage technology, and there are many ways we can make these systems safer. Zinc offers another promising approach, particularly where safety and sustainability are priorities,” Dharmasiri said.

While zinc stores less energy than lithium, it can use water-based electrolytes, reducing reliance on flammable components. Zinc is also abundant and recyclable, making it an attractive complementary option for safer, more sustainable structural batteries.

Embedding energy storage into carbon fiber

Renowned for its lightweight strength, carbon fiber is an ideal building material for structural battery composites, particularly in weight-sensitive sectors like electric vehicles, aerospace and defense.

As Dharmasiri explains, “Traditionally, carbon fiber composites are designed to do one main job: carry mechanical loads while keeping structures lightweight. We are asking whether that same material can do more.”

In a paper recently published in the journal Composites Part B: Engineering, Dharmasiri and her Deakin colleagues Dr. James Randall and Professor Luke Henderson presented a scalable approach to redesigning conventional carbon fiber composites into multifunctional zinc structural batteries.

They do this by modifying carbon fiber surfaces to host electrochemically active materials for energy storage.

“Zinc is particularly interesting for structural batteries because performance is not simply about achieving the highest possible battery energy density,” Dharmasiri says. “A structural battery performs two functions simultaneously, so we need to consider what it contributes to the performance, safety and efficiency of the whole structure.”

At its core, this redesign process involves electrochemical surface modification of the carbon fiber, integrating electroactive zinc and manganese dioxide while maintaining mechanical integrity.

Materials of the future

Dharmasiri hopes to move from laboratory-scale zinc structural battery composites to building engineering components in which structural performance, energy storage, safety and multifunctionality are optimized together.

Reducing the number and weight of separate components could create lighter cars, airplanes and defense craft with greater range, endurance and functionality.

“The same structure could potentially store energy, sense damage and provide electromagnetic protection. Rather than continuously adding separate components for every required task, we could design the material itself to perform several of those functions,” Dharmasiri said.

By bringing chemistry and materials engineering together, Dharmasiri and her colleagues aim to rethink what a structure can do.

Who’s behind this story?

Lisa Lock

BA art history, MA material culture. Former museum editor, paramedic, and transplant coordinator. Editing for Science X since 2021.

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Andrew Zinin

Master’s in physics with research experience. Long-time science news enthusiast. Plays key role in Science X’s editorial success.

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