Cosolvent electrolyte chemistries for high-voltage potassium-ion battery

MK Shen and ZQ Dai and L Fan and HW Fu and YH Geng and J Guan and FF Sun and AM Rao and J Zhou and BG Lu, NATIONAL SCIENCE REVIEW, 11, nwae359 (2024).

DOI: 10.1093/nsr/nwae359

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 in situ 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.

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