Open AccessTernary Ionogel Electrolytes Enable Quasi‐Solid‐State Potassium Dual‐Ion Intercalation Batteries
Author(s) -
Kotronia Antonia,
Edström Kristina,
Brandell Daniel,
Asfaw Habtom Desta
Publication year - 2022
Publication title -
advanced energy and sustainability research
Language(s) - English
Resource type - Journals
ISSN - 2699-9412
DOI - 10.1002/aesr.202100122
Subject(s) - ionic liquid , electrolyte , electrochemical window , materials science , electrochemistry , ternary operation , ionic conductivity , chemical engineering , thermal stability , ion , ionic bonding , intercalation (chemistry) , graphite , inorganic chemistry , chemistry , composite material , electrode , organic chemistry , computer science , engineering , programming language , catalysis
A dual‐ion battery (DIB) is an emerging technology destined for use in stationary energy storage applications. Most DIB prototypes use expensive salt‐concentrated liquid electrolytes to ensure sufficient ion supply and an electrochemical stability window beyond 4.5 V, which is required for anion intercalation in graphite. Herein, the design of a compact quasi‐solid‐state potassium‐based DIB is introduced using ternary ionogel electrolytes (t‐IGEs) prepared from a potassium salt, an ionic liquid, and a poly(ionic liquid). Among a series of combinations, the t‐IGE with optimum mechanical property, thermal stability (>200 °C), and electrochemical performance consists of 30% salt, 28% ionic liquid, and 42% poly(ionic liquid). With ionic conductivity ranging from 0.1 to 1 mS cm −1 at 30–100°C and an electrochemical stability window within 0.5–5.0 V versus K + /K, the t‐IGE is suited for practical MoS 2 –graphite KDIBs. Infusing the ionogel in plain‐weave glass fiber fabrics (≈40 μm thick) further enables the design of more compact KDIBs in which a significant reduction (≈64%) in electrolyte thickness is achieved. The cells are able to deliver specific capacities varying from 80 to 25 mAh g −1 at 10 to 160 mA g −1 , with CEs ranging from ≈90% to 100%.