In a breakthrough that could significantly extend the battery life of electric vehicles (EVs), researchers have developed a new capacitor with an energy density up to 19 times higher than current models.
This development, recently published in the journal Science, came about unexpectedly as scientists worked on novel electronics. This development potentially sets a new standard for EVs, consumer technology and large-scale energy storage solutions.
Unplanned discovery
The team, led by Assistant Professor Sang-Hoon Bae of Washington University, stumbled upon a new material structure that dramatically slows down the rate at which energy dissipates in capacitors without compromising their quick charging capabilities.
Capacitors, unlike batteries, store electricity in an electric field, which allows for rapid charging and discharging. This feature makes them ideal for applications that require quick access to power.
"Dielectric relaxation time can be modulated or induced by a very small gap in the material structure," explained Professor Bae. "This new physical phenomenon is something we hadn’t seen before. It enables us to manipulate dielectric material in such a way that it doesn’t polarise and lose charge capability."
Behind the science
Capacitors typically utilise ferroelectric materials that can retain their polarisation—akin to 'memory'—even after the power is removed.
However, their energy retention over extended periods has traditionally been inferior to that of batteries.
The researchers' new heterostructures, featuring layers of 2D and 3D materials as thin as 30 nanometres, achieve a balance between conductivity and non-conductivity, which enhances energy retention.
These heterostructures include a tiny, unintentionally created gap that increases the relaxation time—the period over which the capacitor retains its charge. This innovative structure could offer an efficiency exceeding 90 per cent, surpassing the efficiency of novel ferroelectric capacitors documented at 86.95 per cent in recent studies.
Implications for electric vehicles
The implications of this technology are broad and impactful.
For EVs, where energy density and rapid charging are paramount, this could mean significantly improved battery life and performance.
Furthermore, the technology could advance the use of capacitors in grid or private industrial applications, where quick, on-demand power is crucial.
This breakthrough also promises enhanced flexibility in how energy is stored and accessed, potentially revolutionising grid-scale energy storage and consumer devices like smartphones and laptops.
In typical smartphones, hundreds of capacitors work alongside the battery to provide quick bursts of energy for functions such as camera flashes.
Looking ahead
The potential for this technology to be scaled up could herald a new era in energy storage, where fast-charging capacitors complement and significantly enhance the capabilities of traditional batteries.
This would not only boost the efficiency of consumer devices but also fortify the infrastructure for renewable energy storage, aligning with global initiatives toward sustainability and reduced carbon footprints.
As the research progresses, the next steps will involve further testing and eventual commercialisation of the technology.
If successful, this could mark a pivotal shift in how energy is stored and used across multiple sectors, driving forward innovations that are both environmentally sustainable and technologically advanced.