Helena Braga explains how self-charging batteries could arrive soon

Graham Whitfield • August 12, 2026 17:27

Helena Braga, a researcher and lecturer at the Faculty of Engineering of the University of Porto (FEUP), said on Expresso’s podcast The Future of the Future that self-charging batteries could be closer than many people think - and outlined how they would work.

Back in 2020, her team laid the groundwork for an innovative battery concept that can recharge itself, by bringing together “negative capacitance and negative resistance” within the same cell.

While it is still hard to find these batteries deployed at industrial scale, Helena Braga believes they “could be coming soon”.

How does this technology work?

According to the lecturer, self-charging batteries share the same basic architecture as lithium-ion batteries: an anode, a cathode and an electrolyte.

The electrolyte is the medium through which ions move between the battery’s anode and cathode (the electrodes), transferring electrical charge and producing an electric current. In other words, the electrolyte is what enables chemical energy to be converted into electrical energy.

In self-charging batteries, however, the “work of putting the ions in the right place is done spontaneously inside the electrolyte”.

How is that possible? In this case the electrolyte is solid - and it is also ferroelectric. That means that “spontaneously, at a certain temperature - without needing to use energy - a region of the material will develop a positive charge and another region will acquire a negative charge; and positive charges and negative charges at a certain distance result in stored energy”. This, in turn, could reduce costs associated with drawing power from the electricity grid.

As well as being solid, these batteries also use sodium ions (salt), since sodium is among the most abundant materials available. Using sodium in batteries is not entirely new, although the versions we already know typically rely on a liquid electrolyte.

Even though it is still far too early to fit these batteries in cars, Helena Braga is confident that it could happen.

What is the future of batteries?

Self-charging batteries are only the tip of the iceberg. In the podcast, the lecturer also mentioned another type of battery that may arrive soon: wireless batteries - that is, batteries without wires. As the name suggests, they would allow charging to be done at a distance.

In Helena Braga’s view, these will be “the future of the future of batteries”, but they are not the only development on the horizon. Solid-state batteries, using electrolytes with sodium and potassium, are, in her words, “a present with one foot in the future”.

In time, such batteries may even exceed the capacity delivered by lithium-ion batteries, although the scientist acknowledges that liquid-state batteries will most likely not be abandoned.

Competition will lower the price

One of the biggest challenges facing the battery-manufacturing industry has been production cost - and Helena Braga also has a perspective on that.

“Europe is trying to catch up with an Asia.”

Helena Braga, researcher and lecturer

She noted that 39 battery gigafactories are planned across Europe, while China is already beginning to limit the creation of new gigafactories within its territory - and that “prices will come down with competition”.

On the driving range of today’s electric cars, the researcher argues that they already offer strong autonomy, pointing to the Lucid Air Grand Touring as an example, with a range of up to 832 km.