Tohoku University researchers and colleagues have demonstrated sodium-ion batteries using hard carbon microlattices produced with an inexpensive 3D printer. According to the researchers, these new, easily fabricated, high-performance carbon microlattice electrodes could be used to make cheaper batteries powered by readily available sodium ions.
Lithium-ion batteries are used in many applications, such as smartphones, electric cars, and many electronic devices, due to their durability, high performance, and energy storage. However, manufacturing these batteries is costly, metal reserves are rapidly depleting, and their extraction can be harmful to the environment. Researchers want to reduce battery manufacturing costs and find a way to unlock the potential of the more widely available sodium ions.
Tohoku University materials scientist Akira Kudo, a Ph.D. student at the University of California Los Angeles, Yuto Katsuyama, and their team 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. Their approach reduced the inactive materials that are used for binding multiple cells together, compacting the battery size and lowering the costs of the ingredients.
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 addressed this by developing an approach that fabricates micro-architected, high-performing negatively charged (anode) electrodes.
Researchers used 3D stereolithography to print microlattice structures made from resin. The microlattices are then shrunk by carbonizing them via a process called pyrolysis.
The resulting anode allows fast transportation of energy-generating ions, in addition to reducing the battery size and slashing manufacturing costs. Alongside all these improvements, the researchers also made the lattice structure finer, which improved its performance. As 3D printers gain increasing resolution, sodium-ion batteries could eventually outperform lithium-ion ones, says Kudo.
Next, the team aims to use this same approach to make positively charged (cathode) electrodes. The ultimate goal is to use these finely architected electrodes for making high-performing, cost-effective sodium-ion batteries.