SCIENCE

Sodium-Ion Batteries: The New Cold and Heat Champions

Sun May 18 2025
Batteries are everywhere, from phones to electric cars. Sodium-ion batteries (SIBs) are a type of battery that has been getting a lot of attention lately. The problem is, most batteries struggle in extreme temperatures. They either freeze up in the cold or overheat in the heat. This is a big issue for places with harsh winters or scorching summers. A new type of electrolyte has been created to tackle this problem. This electrolyte is based on sulfites. It has been designed to work in a wide range of temperatures, from -60 to 60 degrees Celsius. This is a significant improvement over the current electrolytes, which are based on ethers or carbonates. These electrolytes struggle to work in both high and low temperatures. The new electrolyte works by controlling the way ions interact with each other. This speeds up the desolvation process, which is when the ions shed their solvent molecules. At the same time, it maintains strong electrostatic forces, which keep the ions in check. This balance is key to making the electrolyte work in both high and low temperatures. The electrolyte also forms a robust interphase, which is a layer that protects the electrode. This interphase is rich in inorganic materials, which makes it strong and allows ions to move through it easily. This extends the voltage window and temperature range of the battery. The new electrolyte has been tested with different types of cathodes. One type, Na3V2(PO4)2O2F, showed a capacity of 58 mA h g-1 at -50 degrees Celsius. It also cycled stably at 60 degrees Celsius for 300 cycles, retaining 80% of its capacity. Other cathodes, like Na3V2(PO4)3 and NaFe1/3Ni1/3Mn1/3O2, also showed good performance at low temperatures. The new electrolyte has also been tested in a pouch cell, which is a type of battery used in electric vehicles. The pouch cell showed a capacity of 0. 64 A h with 56% capacity retention at -40 degrees Celsius. This is a significant improvement over current batteries. The new electrolyte is a big step forward for SIBs. It shows that it is possible to create batteries that work in a wide range of temperatures. This could lead to the development of all-weather battery systems, which would be a game-changer for many industries. It is important to note that while this new electrolyte shows promise, it is still in the early stages of development. More research is needed to understand its long-term performance and safety. Additionally, the cost of producing this electrolyte needs to be considered. If it is too expensive, it may not be practical for widespread use.

questions

    How does the sulfite-based electrolyte compare to traditional ether- and carbonate-based electrolytes in terms of cost and scalability?
    What are the potential environmental impacts of using sulfite-based electrolytes in sodium-ion batteries?
    How does the desolvation process in sulfite-based electrolytes compare to other electrolyte systems, and what are the implications for battery efficiency?

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