A research team at the Department of Chemistry (Prof. Ji Man Kim) successfully demonstrated a durable nanostructure of ordered mesoporous Tin (Sn)-based intermetallic materials, enabling control of the volume changes during the charge-discharge process. Li-ion batteries (LIBs) are a key-enabling technology for addressing the power and energy demands of electric vehicles and stationary electrical storage for renewable energy, as well as mobile electronics. However, the energy density of currently commercialized LIBs is already close to its technological limit. In order to achieve the battery performances that all applications expect, much effort has been made to develop new electrode materials to improve both the energy density and cycle performance of LIBs. The main goal of this research is to enable energy densities that are higher than the theoretical limit predicted for current lithium ion intercalation batteries.

Tin (Sn) has been considered as an attractive anode material for Li-ion batteries (LIBs) due to the appropriate working potential (average 0.5 V vs. Li/Li+) and high theoretical capacity (993 mAh g-1). However, structural deterioration originated from severe volume variation during the lithiation–delithiation process is one of the most well-known drawbacks, which causes a failure of cycle stability.

The research team developed the preparation and electrochemical behaviors of highly ordered mesoporous CoSn intermetallic anodes which represent superior electrochemical performance, by combining the advantages of intermetallic framework and nanoporous structure.

Furthermore, they unveiled the nanostructural changes during the battery operation by in operando SAXS investigation, so that they can provide more details on volume changes of the electrode materials during cycling. Most promising is that the presence of Co as an electrochemically inactive buffer element in the mesoporous intermetallic materials leads to the durable nanostructure upon prolonged cycling. These findings should give valuable guidance for designing innovative nanostructured material.

The full details of the research was published in the scientific journal Advanced Functional Materials under the subject name; Discovering Dual-Buffer Effects on Lithium Storage: Durable Nanostructure of Ordered Mesoporous Co-Sn Intermetallic Electrode.