Researchers at Chalmers University of Technology have made significant strides in the development of a carbon fibre structural battery, combining strength and energy storage capabilities. This innovative battery is as stiff as aluminium and dense enough in energy storage to be applied in commercial products.
The study, recently published in Advanced Materials, builds on years of research at Chalmers and the KTH Royal Institute of Technology. When the team, led by Professor Leif Asp, first published results in 2018 showing that carbon fibre could act as electrodes in lithium-ion batteries, the discovery gained widespread attention. Professor Asp describes the new battery as having multifunctional properties that surpass its predecessor, making it the most advanced structural battery developed to date.
Since the initial findings, the research team has made considerable advancements in improving both the stiffness and energy density of the battery. In 2021, the battery reached an energy density of 24 watt-hours per kilogram (Wh/kg), about 20% of the capacity of standard lithium-ion batteries. This has now been increased to 30 Wh/kg. Although still lower than current batteries, the design of this structural battery compensates by reducing overall vehicle weight, leading to greater energy efficiency.
The research team estimates that electric cars using structural batteries could travel up to 70% farther compared to current models.
For vehicles, safety and structural integrity are critical. The new carbon fibre battery meets these high demands by significantly increasing its stiffness, or elastic modulus, from 25 to 70 gigapascal (GPa). This makes the material comparable to aluminium in strength, but with a much lower weight, allowing for lighter, more energy-efficient vehicles.
Structural batteries are materials that both store energy and support structural loads. By integrating energy storage within the construction material, products like electric cars, drones, and mobile devices can be made lighter and more efficient. This innovative approach reduces the need for heavier components, such as copper or aluminium current collectors, and eliminates the need for conflict metals like cobalt and manganese.
The ultimate goal of this research is to commercialise the technology. Chalmers University has established a new venture, Sinonus AB, to bring the technology closer to market. While much engineering work remains before the battery can be mass-produced for vehicles or consumer electronics, the potential applications are vast.
The automotive and aerospace industries have shown significant interest in this groundbreaking technology, which could revolutionise the transport sector by addressing its growing energy demands. Large-scale investments will be required to further develop and commercialise the batteries.
With continued research and investment, this technology could revolutionise energy storage and efficiency in a wide range of industries.
