biostudies-literatureQue LMOST | National Natural Science Foundation of China (NSFC)MOST | National Natural Science Foundation of Chinae2311075121https://www.ebi.ac.uk/biostudies/studies/S-EPMC11047101biostudies-literatureUnknown121(17)Voltage oscillation at subzero in sodium-ion batteries (SIBs) has been a common but overlooked scenario, almost yet to be understood. For example, the phenomenon seriously deteriorates the performance of Na3V2(PO4)3 (NVP) cathode in PC (propylene carbonate)/EC (ethylene carbonate)-based electrolyte at -20 °C. Here, the correlation between voltage oscillation, structural evolution, and electrolytes has been revealed based on theoretical calculations, in-/ex-situ techniques, and cross-experiments. It is found that the local phase transition of the Na3V2(PO4)3 (NVP) cathode in PC/EC-based electrolyte at -20 °C should be responsible for the oscillatory phenomenon. Furthermore, the low exchange current densiProceedings of the National Academy of Sciences of the United States of AmericaUnveil the origin of voltage oscillation for sodium-ion batteries operating at -40 °C.PMC1104710151902072Que LWu JYang ZZhao RFeng YYu FLuo HChao DSun ZLan ZfalseUnveil the origin of voltage oscillation for sodium-ion batteries operating at -40 °C.Voltage oscillation at subzero in sodium-ion batteries (SIBs) has been a common but overlooked scenario, almost yet to be understood. For example, the phenomenon seriously deteriorates the performance of Na3V2(PO4)3 (NVP) cathode in PC (propylene carbonate)/EC (ethylene carbonate)-based electrolyte at -20 °C. Here, the correlation between voltage oscillation, structural evolution, and electrolytes has been revealed based on theoretical calculations, in-/ex-situ techniques, and cross-experiments. It is found that the local phase transition of the Na3V2(PO4)3 (NVP) cathode in PC/EC-based electrolyte at -20 °C should be responsible for the oscillatory phenomenon. Furthermore, the low exchange current densi2024-01-01T00:00:00Z2024 Apr2025-04-04T11:05:39.623Z2025-04-04T11:05:39.623ZS-EPMC110471013862594210.1073/pnas.2311075121