New, easily fabricated, high-performance carbon microlattice electrodes could soon be used to make cheaper batteries powered by readily available sodium ions. The approach was published by Tohoku University researchers and colleagues in the journal Small, under the title “A 3D printed, freestanding carbon lattice for sodium ion batteries”.
Lithium ion batteries are used in a wide range of applications, from smartphones to electric cars – thanks to their high performance and ability to store large amounts of energy. However, manufacturing these batteries is costly, the metal’s reserves are quickly getting depleted, and its extraction can be harmful to the environment. Scientists are looking for ways to reduce battery manufacturing costs and unlock the potential of the more widely available sodium ions.
Akira Kudo, materials scientist at Tohoku University, Yuto Katsuyama, Ph.D. student at the University of California, and colleagues are looking at ways to achieve high-performance, low-cost batteries by increasing the loaded amount of active materials used to make a battery into a single battery cell. This would reduce the inactive materials that are used for binding multiple cells together. However, this requires the fabrication of thicker electrodes, which would restrict ion movement – and thus that of electric charge – within the battery.
Kudo and his team have addressed this by developing an approach that fabricates micro-architected, high-performing, negatively charged (anode) electrodes.
The approach involves using 3D stereolithography to print micro lattice structures made from resin. The micro lattices are then shrunk by carbonizing them via a process called pyrolysis. The resulting hard carbon anodes were found to allow fast transportation of energy-generating ions. As the team made the lattice structure finer, its performance improved. According to Kudo, as 3D printers gain increasing resolution, sodium ion batteries could eventually outperform lithium ion ones.
The team next aims to use this same approach to make positively charged (cathode) electrodes. The ultimate goal is to use these finely architected 3D printed electrodes for making high-performing, cost-effective sodium ion batteries.