A free-sealed high-voltage aqueous polymeric sodium battery enabling operation at −25°C

• Main Authors: Bai, Y.-Z (Author), Cai, T.-X (Author), Chen, J. (Author), Dong, W.-J (Author), Huang, F.-Q (Author), Rong, J.-Z (Author), Wu, T. (Author), Wu, Y.-K (Author), Xu, S.-M (Author), Zhao, W. (Author), Zhao, X. (Author)
• Format: Article
• Language: English
• Published: Cell Press 2022
• Subjects: aqueous polymeric sodium batteries; fluorine doping; free seal; high rate; high voltage; hydrogen bonding; low temperature; P2-type cathode; ultrathin; water in ionogel
• Online Access: View Fulltext in Publisher
• ISBN: 26663864 (ISSN)
• DOI: 10.1016/j.xcrp.2022.100805

An increasing demand for electric vehicles and flexible electronics focuses attention on developing a safe, high-energy, and sustainable battery that can work under severe conditions. Emerging high-voltage aqueous batteries based on highly concentrated salts and molecular crowding electrolytes are likely to be hampered by their poor low-temperature performance because of a high freezing point and salting out at low temperature. Inspired by the antifreezing ionogel electrolyte for transport measurements at subzero temperatures, we design a water-in-ionogel electrolyte with a low salt-concentration (2m NaTFSI) and high operational voltage (3.0 V) by changing the hydrogen bonding and introducing fluoride additives for low-temperature operation. A full cell with a P2-type Na2/3Mn2/3Co1/3O1.98F0.02 cathode and hard-carbon anode could deliver high energy densities of 109 and 23.4 Wh kg−1 at room temperature and −25°C. This eco-friendly aqueous polymeric battery could be free sealed and perform in water. This work opens an avenue for designing high-energy, free-sealed aqueous batteries for low-cost, sustainable energy storage, enabling subzero temperature operation. © 2022