Reducing the operating temperature of molten sodium-sulfur batteries (~350 °C) is critical to create safe and cost-effective devices for large-scale energy storage. By raising the surface treatment temperature with lead acetate trihydrate, we can significantly improve sodium wettability on ß"-Al2O3 solid electrolyte at a low temperature of 120 °C, previously unattained. In turn, the Na S cell can reach a capacity as high as 520.2mAh/g and stable cycling over 1000 cycles at 120 °C, which is slightly higher than the melting point of sodium (98 °C). Analyzing surfaces treated at different temperatures, the deposited Pb particles show similar morphologies but distinct compositions, inferring a strong correlation between passivation and performance.
Revised: January 7, 2021 |
Published: January 4, 2021