NanoName: Improving sodium ion battery perfomance with nanostructured metallate anodes

The NANONAME project focuses on Na-ion batteries as an alternative and supplement to Li-ion batteries. Expectedly will Na-ion batteries find considerable commercial use within a time frame of a few years, in other niches than those dominated by Li-ion batteries for the transportation sector, e.g. stationary applications. Na-based batteries are competitive from reasons like accessibility of elements, toxicity, price, environmental footprint. Our focus is anode materials. These are extremely important for the well-functioning of a ion-battery. In Na-ion batteries, unlike LI-ion batteries, graphite can not be used as anode for thermodynamic reasons. In our research we therefore focus on anode materials that first undergoes a conversion reaction, followed by an alloying reaction. The first step is typically non reversible. This makes the alloying step critical. In this reaction, bismuth exchanges three electrons per atom, and is forming Na3Bi with Bi(-III). We form a sodium bismuthides. The considerable number of electrons exchanged per Bi give a high charge capacity. Excellent reversibility and low losses is hence our target for the practical charge/discharge cycling. In order to reach this goals, the philosophy in NANONAME has two main legs; formation of BI-nanoparticles within a flexible oxide matrix, and use of RGO (reduced grafenoxide), preferably as a conducting two-dimensional nanomaterial between Bi-nanoparticles and the converted oxide matrix. At the same time we will explore whether transition metal cations in the matrix can be made electrochemically active. materials as anodes, where the essential electrochemical reaction step represents alloying under formation of Na-Bi-ides. We are using operando characterizations at large scale synchrotron facilities (diffraction/PDF, XAS and tomography) plus DFT/MD simulations to address these issues. Certain detailed plans on advanced characterization have unfortunately not been able to be realized, owing to the international covid situation. In Norway NANONAME interacts with academic and applied (industry) groups through the FME centre Mozees.

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Lithium batteries are keys to electric propulsion in the transportation sector. Improved materials will significantly impact future developments; distance, charging, lifetime, safety, costs etc. Na-ion batteries represent a real alternative, technologically less mature, but with huge potential. However, certain breakthroughs are called for, among these reliable high capacity anodes. NanoName launches a new class of anode materials, where UiO has secured IP rights, and recent developments are published by us in top journals. We suggest now how these materials can be significantly improved, by nanostructuring and chemical modifications, and how reduced graphene oxide will help in achieving highly reversible and stable cycling. Our strategy is to combine the unique expertise of the NAFUMA group at UiO, on (nano)materials synthesis, operando characterization and DFT/MD simulations, and gain new insight to governing mechanism for the anode performance. In turn this insight will be fed back into the synthesis loop for bringing the new knowledge into new materials, and so on. In the project, the use of operando techniques that allows detailed studies of the battery materials (and the individual components) in real life during charge and discharge is essential. As well electrons, X-rays/synchrotron radiation and neutrons will be used, thereby adding to our leadership in operando battery studies. These material systems are chosen, both because of excellent performance, but also for fulfilling requirements on availability, toxicity, costs, environmental footprint for future sustainable solutions, as described in our perspectives on responsible research and innovation. We will educate/train 1PhD and 1 Pdoc, likewise involve highly competent researchers on part time. Our ambition is to publish >6 papers in top journals, and submit one DOFI for patent evaluation. The project will closely interact with academics, industry and end users in the MoZees FME, where we are a partner.