Sulfonylamide-Based Ionic Liquids for High-Voltage Potassium-Ion Batteries with Honeycomb Layered Cathode Oxides

Abstract

The world is at the cusp of a new era where pivotal importance is being attached to the development of sustainable and high-performance energy storage systems. Potassium-ion batteries are deemed not only as cheap battery candidates, but also as the penultimate high-voltage energy storage systems within the monovalent-cation chemistries. However, their performance and sustainability are undermined by the lack of suitable electrolytes for high-voltage operation particularly due to the limited availability of cathode materials. Here, the potential of ionic liquids based on potassium bis(trifluoromethanesulfonyl)amide (KTFSA) as high-voltage electrolytes is presented by assessing their physicochemical properties, along with the electrochemical properties upon coupling with new high-voltage layered cathode materials. These ionic liquids demonstrate a lower redox potential for potassium dissolution / deposition (with a wide voltage tolerance of around $6.0$ $\mathrm{V}$), placing them as feasible and safe electrolytes for high-voltage potassium-ion battery configuration. This is proven by matching this electrolyte with new high-voltage layered cathode compositions, demonstrating stable electrochemical performance. The present findings of electrochemically stable ionic liquids based on potassium bis(trifluoromethanesulfonyl)amide will bolster further advancement of high-performance cathode materials, whose performance at high-voltage regimes were apparently restricted by the paucity of suitable and compatible electrolytes.

29 pages, 8 figures, 1 table, 1 cover art

Cited by in corpus (8)

• Mixed Alkali-Ion Transport and Storage in Atomic-Disordered Honeycomb Layered $\mathrm{NaKN}{\mathrm{i}}_2\mathrm{Te}{\mathrm{O}}_6$
• An Idealised Approach of Geometry and Topology to the Diffusion of Cations in Honeycomb Layered Oxide Frameworks
• Unveiling Structural Disorders in Honeycomb Layered Oxide: $\mathrm{N}{\mathrm{a}}_2\mathrm{N}{\mathrm{i}}_2\mathrm{Te}{\mathrm{O}}_6$
• Topological Defects and Unique Stacking Disorders in Honeycomb Layered Oxide ${\mathrm{K}}_2\mathrm{N}{\mathrm{i}}_2\mathrm{Te}{\mathrm{O}}_6$ Nanomaterials: Implications for Rechargeable Batteries
• Implications of Coordination Chemistry to Cationic Interactions in Honeycomb Layered Nickel Tellurates
• Honeycomb Layered Oxides With Silver Atom Bilayers and Emergence of Non-Abelian SU(2) Interactions
• Coronene: A High-Voltage Anion De-insertion Cathode for Potassium-Ion Battery
• Advances in honeycomb layered oxides: Part I -- Syntheses and Characterisations of Pnictogen- and Chalcogen-Based Honeycomb Layered Oxides