The Possible Solutions for the Cell of Post-Lithium Era, New Ideas for Sodium-Ion Batteries

Abstract

Fossil fuels are the most used energy source in the world, which risks in environmental pollution, resource depletion or geopolitical conflicts. These all have led to the emergence of intermittent renewable and cleaner energy sources such as wind, solar and wave, for which there is a strong demand for huge energy storages. One of the most known technology is Li-ion, however the alternatives must be researched to meet the increasing needs. One of the ideas is sodium-ion technology, which is one of the most popular post-lithium cell technology.Sodium, in contrast to lithium, has almost unlimited resources everywhere including the vast reserves in the oceans. In addition, sodium is the one of the most abundant element in the Earth’s crust. The price of sodium is low compared to lithium. Furthermore, thanks to the similar physical properties of those two elements, NIBs share similar electrochemistry and fabrication techniques to LIBs. However, there are some obvious differences between NIBs and LIBs systems. The size difference affects transport properties, phase stability, and interphase formation (Hwang et al., 2017). Because of those dissimilarities, many battery components cannot be directly transplanted from a LIB to a NIB. Moreover, since Na-based batteries are an emerging technology, there is a relative lack of new materials that would enable the electrochemistry of Na and the discovery of new redox couples (Slater et al., 2013). For instance, a significant hurdle for sodium electrochemical systems is the lack of high-performance electrodes and electrolyte materials that are easy to synthesize, safe, non-toxic, durable, and inexpensive (Slater et al., 2013).That is why, there are many challenges due to the Na-ion technology, especially introducing novel cathodic materials. To answer this problem, several new types of electrodes, containing Ti, Y, Ni and Mn additives will be introduced in this presentation The compatibility of cathodes with electrolyte is the next topic, which will be presented. As the example, modern electrolytes, containing the low coordinating Hückel type salt (4,5-dicyano-2-(trifluoromethyl)imidazolate, NaTDI) as a main electrolyte component and different additives and solvent mixtures will be shown. The new formulations with the best conductivity performance, physicochemical stability, and interfacial contact with electrodes were examined and verified. Using the SEM, Raman, EDS, and XRPD analysis, the full characterization of the active materials and electrodes was performed to introduce the new possible electrode-electrolyte compositions. All of these led to presenting the new possible compositions of electrodes and electrolytes, which gives new perspectives for Na-ion battery technologies.ReferencesSlater, M. D., Kim, D., Lee, E., & Johnson, C. S. (2013). Sodium-Ion Batteries. Advanced Functional Materials, 23(8), 947–958. https://doi.org/10.1002/ADFM.201200691Hwang, J. Y., Myung, S. T., & Sun, Y. K. (2017). Sodium-ion batteries: present and future. Chemical Society Reviews, 46(12), 3529–3614. https://doi.org/10.1039/C6CS00776GAcknowledgementsStudies were funded by ENERGYTECH-1 project granted by Warsaw University of Technology under the program Excellence Initiative: Research University (ID-UB).