Multiple Electron Transfers Enable High-Capacity Cathode Through Stable Anionic Redox.

Single-electron transfer, low alkali metal contents, and large-molecular masses limit the capacity of cathodes. This study uses a cost-effective and light-molecular-mass orthosilicate material, KFeSiO, with a high initial potassium content, as a cathode for potassium-ion batteries to enable the transfer of more than one electron. Despite the limited valence change of Fe ions during cycling, KFeSiO can undergo multiple electron transfers via successive oxygen anionic redox reactions to generate a high reversible capacity.

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

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 synchrotron-based wide-angle X-ray scattering experiments.