A team of scientists in Germany has discovered a clever way to make batteries more powerful, cheaper to produce, and faster to charge—all thanks to something that looks a bit like a metal sponge.
Researchers at the Max Planck Institute for Medical Research, led by Professor Joachim Spatz, have developed metal fleeces that can transform how batteries work by letting them store more energy and charge much more quickly.
At the heart of every battery are two key components: active materials, which store the energy, and contact materials, which move the electrical charge in and out of the battery.
In today’s lithium-ion batteries, the contact materials are flat metal foils—typically copper or aluminum—onto which the active material is layered.
But there’s a major trade-off in battery design: if the active layer is thick, the battery stores more energy but charges slowly. If it’s thin, it charges quickly but stores less energy.
Spatz’s team found a way to break this trade-off using a new material design. Instead of flat foils, they created a soft, 3D metal fleece made of very thin wires.
This fleece acts like a superhighway for lithium ions—the charged particles that carry energy inside the battery.
These ions move slowly through regular liquid-filled battery materials, but when they touch the metal fleece, they move up to 56 times faster. This is because the ions shed their bulky liquid “coat” and glide across the metal surface in what scientists call a Helmholtz layer.
By weaving the active material into this metal fleece, the researchers created battery electrodes that are up to ten times thicker than those in today’s batteries—without slowing down charging speed.
In fact, these new electrodes could increase a battery’s energy density by up to 85%, meaning electric cars could drive much farther on a single charge.
Not only are these metal fleece batteries more powerful, but they’re also easier and cheaper to make.
Traditional battery manufacturing involves complicated steps and harmful solvents to apply thin layers of active material onto metal foils.
With the new method, the active material can simply be added as a dry powder into the fleece, saving up to 40% on production costs and requiring much less factory space.
To bring this innovation to the real world, Spatz has already launched a startup and is working with major car manufacturers.
He believes this breakthrough gives European companies a real shot at becoming global leaders in battery technology, closing the gap with Asian manufacturers and even surpassing them.
This new design could mark the beginning of a battery revolution—one that powers our cars, phones, and future with more speed, range, and efficiency than ever before.
