Stable performance of an all-solid-state Li metal cell coupled with a high-voltage NCA cathode and ultra-high lithium content poly(ionic liquid)s-based polymer electrolyte

Abstract

A poly(ionic liquid)s binder can provide stable performance of high-voltage composite cathodes based on lithium nickel cobalt aluminium oxide (LiNi0.8Co0.15Al0.05O2 or NCA), up to 4.5 V (vs. Li+/Li0) at 50 °C for an electrode with high areal capacity up to 1.6 mAh cm−2. A reversible capacity of more than 150 mAh g−1 in an all-solid-state device using a highly concentrated poly(ionic liquid)s-based composite polymer electrolyte is achieved with high-capacity retention on cycling. Characterization of the composite electrode and polymer electrolyte post-cycling using scanning electron microscopy confirms stable behaviour with only small volume changes evident. This report thus demonstrates these solid polymer electrolytes as promising for high energy density high-voltage all-solid-state lithium (Li) batteries.