Multi-functional Flexible Aqueous Sodium-Ion Batteries with High Safety

From Multi-functional Flexible Aqueous Sodium-Ion Batteries with High Safety

The development of wearable and implantable electrical devices has been in great demand recently. However, most existing energy storage systems are based on strong corrosive or toxic electrolytes, posing a huge safety hazard as a result of solution leakage.

Here, we have developed a family of safe and flexible belt- and fiber-shaped aqueous sodium-ion batteries (SIBs) by using various Na+-containing aqueous electrolytes, including Na2SO4 solution, normal saline, and cell-culture medium. The resulting SIBs exhibit high flexibility and excellent electrochemical performance and can be safely applied in wearable electronics. Flexible SIBs with normal saline or cell-culture medium as the electrolyte showed excellent performance, indicating potential application in implantable electronic devices.

In addition, the fiber-shaped electrode in normal saline or cell-culture medium electrolyte can consume O2 and change the pH, implying promising application in biological and medical investigations.