Cosolvent electrolyte chemistries for high-voltage potassium-ion battery.

Shen, Mengkang; Dai, Zhongqin; Fan, Ling; Fu, Hongwei; Geng, Yuanhui; Guan, Jie; Sun, Fanfei; Rao, Apparao M; Zhou, Jiang; Lu, Bingan

The poor oxidation resistance of traditional electrolytes has hampered the development of high-voltage potassium-ion battery technology. Here, we present a cosolvent electrolyte design strategy to overcome the high-voltage limitations of potassium-ion electrolyte chemistries. The cosolvent electrolyte breaks the dissolution limitation of the salt through ion–dipole interactions, significantly enlarging the anion-rich solvation clusters, as verified by the insitu synchrotron-based wide-angle X-ray scattering experiments. Furthermore, the large anion-rich solvation clusters also facilitate the formation of an effective electrode–electrolyte interphase, thereby enhancing compatibility with high-voltage electrodes. The cosolvent electrolyte enables K||Prussian blue cells (2–4.5 V) to operate for >700 cycles with a capacity retention of 91.9%. Our cosolvent electrolyte design strategy paves new avenues for the development of high-voltage potassium-ion batteries and beyond.

ELECTROLYTES; SOLVATION; ELECTRODES; OXIDATION; STORAGE batteries; POTASSIUM ions

National Science Review, 2024, Vol 11, Issue 11, p1

2095-5138

Academic Journal

10.1093/nsr/nwae359