The University of Oldenburg, Germany, has shared in its publication Einblicke how researchers, led by Dmitry Momotenko, have developed a new technique for additively manufacturing ultrasmall metallic objects with the aim to increase the surface area of battery electrodes in order to reduce charging time.
The team built and programmed the lab’s three Additive Manufacturing machines themselves to function on this smaller scale. Oldenburg explained that the team are able to additively manufacture a variety of forms and structures in copper, silver, nickel, nickel-manganese and nickel-cobalt.
“A coloured saline solution flows through delicate tubes into the thin capillary tube, which in turn contains a hair-thin piece of wire – the anode,” stated Momotenko. “It closes the circuit with the negatively polarised cathode, a gold-plated silicon flake smaller than a fingernail, which is also the surface on which the printing takes place. Micromotors and special crystals that morph instantaneously when an electrical voltage is applied rapidly move the nozzle by fractions of a millimetre in all three spatial directions.”
THE WORLD OF METAL AM TO YOUR INBOX
Subscribe to our weekly newsletter
The team aims to reduce charging times by allowing the ions to move quickly between anode and cathode by interlocking the two at nanoscale.
Momotenko explained, “With the current battery design, charging takes so long because the electrodes are relatively thick and far apart.”
But whilst nanoscale Additive Manufacturing of plastics has already been harnessed, transferring this to metals has proved difficult – and producing battery structures of the necessary nano dimensions has not yet been possible. This is the focus of Momotenko’s NANO-3D-LION project.
Funded by a European Research Council Grand awarded in March 2021, the research group now has four members working to develop nanoscale Additive Manufacturing techniques with the aim of creating ‘active battery materials with ultrasmall structural features.’
Liasan Khasanova, a PhD student in the Electrochemical Nanotechnology Group, will focus on lithium compounds in the hopes to discover how the electrode materials used in lithium batteries can be Additively Manufactured. Whereas PhD student Karuna Kanes focuses on optimising the precision of the build nozzle. Master’s student Simon Sprengel is also working on the team to investigate the possibility of producing cathode and anode material simultaneously in just one step, in order to achieve this two different metals need to be additively manufactured in combination.
The team is having to navigate a variety of obstacles during this process, including the reactivity of lithium. In an attempt to combat this, the team acquired a laboratory glove box that is about three metres long with handling gloves built into one side.
“On the one hand, we are working on the chemistry needed to produce active electrode materials at the nanoscale; on the other, we are trying to adapt the printing technology to these materials,” shared Momotenko.
Although Momotenko is currently working on this development, he is still planning other ideas, such as using this Additive Manufacturing technique to “produce metal structures that allow for a more targeted control of chemical reactions” as well as wanting to manufacture sensors that can detect individual molecules.
“That would be helpful in medicine, for detecting tumour markers or biomarkers for Alzheimer’s at extremely low concentrations, for example,” Momotenko stated.