Recently, Prof. Que Lanfang from the College of Materials Science and Engineering of Huaqiao University (HQU) and her team have made significant progress in developing sodium-ion batteries at low temperatures. Their research paper titled “Unveil the Origin of Voltage Oscillation for Sodium-Ion Batteries Operating at −40oC” was published in theProceedings of the National Academy of Sciences(PNAS), one of the world’s most-cited and comprehensive multidisciplinary scientific journals..
Sodium-ion batteries (SIBs) have been considered as a a potential large-scale energy storage technology owing to its long-duration energy storage anywhere. More stringent operational requirements should be satisfied to achieve their high-quality development, such as high rate charging and discharging as well as the ability to operate stably at extreme temperatures. However, extreme operating conditions often lead to problems at the particle-electrode level, including inter-particle or intra-particle state of charge heterogeneity, polarization-driven side reactions at low temperatures, and kinetic control transitions triggered by temperature changes. These reactions present complex and unbalanced features that significantly affect the overall performance of SIBs. It is a more challenging task to accurately capture and understand these phenomena in operating and the cycle life of battery.
Based on the previous research work on low-temperature metal ion batteries and theoretical calculations (Angew. Chem. Int. Ed. 2022, 61, e202213416; Adv. Mater. 2023, 35, 2307592), the research team revealed the origin of low-temperature voltage oscillation of SIBs and its controlling factors, investigated voltage oscillation behaviour of NVP (vanadium phosphate) anodes in PC (propylene carbonate) /EC (ethylene carbonate)-based electrolytes by electrochemical tests, in-situ techniques and simulations combined with theoretical calculations. These results also establish a clear link between the above phenomenon with local phase transformation of SIBs at low temperatures. The paper thoroughly examined and analyzed the main factors affecting the low-temperature local phase transformation of the NVP anode in PC/EC-based electrolytes, and proposed a strategy to eliminate the low-temperature voltage oscillations to construct a Na-ion full battery with excellent low-temperature adaptability and cycle stability. These results has provided new perspectives on performance limitations and stability maintenance faced by SIBs under extreme operating conditions.
The paper was published with HQU as the first affiliation and Prof. Que Lanfang the first and corresponding author. Co-corresponding authors also include Prof. Chao Dongliang from Fudan University and Prof. Luo Hao from Xiamen University of Technology. The research was funded by the National Natural Science Foundation of China, the Natural Science Foundation of Fujian Province, the Natural Science Foundation of Xiamen and the Scientific Research Fund of Huaqiao University.
Link to the Paper:https://www.pnas.org/doi/10.1073/pnas.2311075121
(Editor: Wei Linying)
