XJTU achieves progress in high-safety sodium ion battery research
The results of Professor Pengfei Wang's research team, published in Journal of the American Chemical Society.
Professor Pengfei Wang's research team at Xi'an Jiaotong University's (XJTU) School of Electrical Engineering has designed a flame-retardant perfluorinated electrolyte with high stability and safety by regulating anion-cation interactions.
When solvents with varying coordination numbers engage in solvation interactions with sodium ions, the overall coordination number of the electrolyte is effectively reduced, promoting the aggregation of anions in the solvation structure.
This facilitates the construction of a high-performance, NaF-rich CEI interphase derived from anions on the electrode surface. Electrochemical performance tests, theoretical simulations, and interface characterization collectively demonstrate that this thin and stable electrode/electrolyte interface effectively suppresses parasitic reactions between electrodes and electrolytes, enhances interfacial stability, and promotes rapid sodium-ion transport across the interface.
While maintaining exceptional flame-retardant properties, this electrolyte exhibits excellent compatibility with both Na0.95Ni0.4Fe0.15Mn0.3Ti0.15O2 (NFMT) cathodes and hard carbon (HC) anodes. The NFMT cathode demonstrates a discharge specific capacity of up to 169.7 mA h g⁻¹ and retains stable cycling performance over 500 cycles at a 1C rate.
NFMT//HC pouch cells also exhibit stable cyclability in this electrolyte, achieving 86.8 percent capacity retention after 100 cycles at a 0.5C rate. This work provides an effective strategy for designing high-safety electrolytes. It offers novel theoretical insights from the solvation structure perspective, significantly advancing the technological breakthroughs and commercialization of safe sodium-ion batteries.
This research, titled Cation–Anion Regulation Engineering in a Flame-Retardant Electrolyte toward Safe Na-Ion Batteries with Appealing Stability, was published in the prestigious Journal of the American Chemical Society.
