Nature Communications (Jan 2024)

Rapid-charging aluminium-sulfur batteries operated at 85 °C with a quaternary molten salt electrolyte

  • Jiashen Meng,
  • Xufeng Hong,
  • Zhitong Xiao,
  • Linhan Xu,
  • Lujun Zhu,
  • Yongfeng Jia,
  • Fang Liu,
  • Liqiang Mai,
  • Quanquan Pang

DOI
https://doi.org/10.1038/s41467-024-44691-8
Journal volume & issue
Vol. 15, no. 1
pp. 1 – 10

Abstract

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Abstract Molten salt aluminum-sulfur batteries are based exclusively on resourcefully sustainable materials, and are promising for large-scale energy storage owed to their high-rate capability and moderate energy density; but the operating temperature is still high, prohibiting their applications. Here we report a rapid-charging aluminium-sulfur battery operated at a sub-water-boiling temperature of 85 °C with a tamed quaternary molten salt electrolyte. The quaternary alkali chloroaluminate melt – possessing abundant electrochemically active high-order Al-Cl clusters and yet exhibiting a low melting point – facilitates fast Al3+ desolvation. A nitrogen-functionalized porous carbon further mediates the sulfur reaction, enabling the battery with rapid-charging capability and excellent cycling stability with 85.4% capacity retention over 1400 cycles at a charging rate of 1 C. Importantly, we demonstrate that the asymmetric sulfur reaction mechanism that involves formation of polysulfide intermediates, as revealed by operando X-ray absorption spectroscopy, accounts for the high reaction kinetics at such temperature wherein the thermal management can be greatly simplified by using water as the heating media.