Non-technical Abstract Sodium-ion batteries have important advantages over lithium-ion batteries: unlike lithium, sodium is abundant, inexpensive, and is not geographically concentrated. There is sufficient sodium to provide economically the quantity of batteries needed for large-scale applications such as grid-level energy storage and for a global transition to electric vehicles. These qualities give sodium-ion batteries the potential to overcome the barriers that currently prevent the widespread adoption of intermittent renewable energy sources such as wind and solar power. The principal scientific obstacle for the realization of sodium-ion batteries lies on the anode side, where hard carbon is one of the most promising anode materials. Hard carbon electrodes can be synthesized cheaply from abundant precursors such as sucrose, cellulose, and peat moss. With the support of the Solid State and Materials Chemistry program in the Division of Materials Research, the research team work to provide the understanding to unlock the potential of these materials and guide the future development of sodium-ion batteries. More broadly, the knowledge generated with this research enriches our general understanding of carbon materials and could initiate a new research frontier tailoring non-graphitic carbon materials for other applications. On an educational level, this project provides highly collaborative training opportunities in materials chemistry for graduate students. Through well-established pre-college outreach activities at OSU, this project also integrates under-represented K-12 students in order to inspire their interests in science, engineering and technology.
Sodium shares many innate chemical properties with lithium, giving sodium-ion batteries (NIBs) similar characteristics to the well-known lithium-ion batteries (LIBs). However, Na ions are much larger than Li ions besides other differences, so many of the mechanisms for Li-ion storage are not applicable to Na ions. The PIs' preliminary results show that the prevailing model of Na storage in hard carbon is inconsistent with systematic experimental results. The attendant knowledge gap is holding back the realization of next generation NIBs, and thus the PIs work to elucidate the new model of basic mechanisms of Na-ion storage in hard carbon and test the model. The research is conducted to accomplish three goals: (1) Generate detailed atomic level understanding of the structure of hard carbons. (2) Elucidate the underpinning mechanisms of Na-ion insertion in hard carbon. (3) Test empirically that the new model is predictive of the relationship between the physicochemical properties of hard carbon and the corresponding electrochemical behavior in NIBs. To achieve the goals, the team of investigators brings together expertise in synthesis and electrochemical characterization of hard carbon, advanced atomistic and morphological characterization of materials, and atomistic modeling of carbon structures.
