A new battery design that could significantly extend the range of electric vehicles has been developed by researchers at the University of Surrey’s Advanced Technology Institute (ATI).
In a study published in the ACS Applied Energy Materials journal, researchers have introduced the lithium-ion battery anode that delivers some of the highest energy storage capacities reported for silicon–carbon nanotube systems, while maintaining stability over hundreds of charge cycles.
Lithium-ion batteries power much of modern technology. Graphite, the most commonly used anode material, is stable but limited in the amount of energy it can store. Silicon, on the other hand, offers far greater capacity, but it expands during charging, causing it to crack and degrade over time.
To overcome this, the research team developed a Vertically Integrated Silicon–Carbon Nanotube (VISiCNT) structure. The design grows dense forests of carbon nanotubes directly onto copper foil and coats them with a thin layer of silicon, creating a flexible, conductive scaffold that can absorb expansion while maintaining performance.
The resulting anode can store a very large amount of energy for its weight. In laboratory tests, it stored more than 3,500 milliampere-hours per gram – close to the maximum possible for silicon and far higher than the graphite (370mAh/g) used in today’s batteries. It also demonstrated improved stability and performance over repeated charge cycles.
“There’s been a growing push for battery innovation, as many of today’s technologies are limited by how much energy batteries can store. The VISiCNT design offers a practical route to harness silicon’s huge storage capability without sacrificing cycle life,” said Dr Muhammad Ahmad, Research Fellow, University of Guildford.
“This is a much-needed breakthrough, delivering very high capacity, fast charging and long-term durability, while bringing us closer to batteries that can power electric vehicles and everyday devices for much longer on a single charge.”
The carbon nanotubes are grown directly onto copper – the material already used in commercial batteries – using a scalable manufacturing process. According to the University of Surrey, this could make it easier to integrate the technology into existing industrial production lines.
“This work is an important step towards bringing CNT-silicon anodes out of the lab and into real-world manufacturing,” said said Professor Ravi Silva, distinguished professor, interim director at the Institute for Sustainability (IfS), director at the Advanced Technology Institute (ATI) and head of the NanoElectronics Centre, University of Surrey.
“We can grow carbon nanotube structures directly onto copper foil at speed and tailor the silicon layer for stability, meaning this approach could be integrated into existing battery production lines with minimal disruption. The technology has clear potential not just for electric vehicles, but also for grid storage and smaller batteries used in microelectronics.”
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