A 2D Conductive Organic–Inorganic Hybrid with Extraordinary Volumetric Capacitance at Minimal Swelling

Abstract

Abstract Rational design and synthesis of 2D organic–inorganic hybrid materials is important for transformative technological advances for energy storage. Here, a 2D conductive hybrid lamella and its intercalation properties for thin‐film supercapacitors are reported. The 2D organic–inorganic hybrid lamella comprises periodically stacked 2D nanosheets with 11.81 Å basal spacing, and is electronically conductive (605 S m −1 ). In contrast to the pre‐existing organic‐based 2D materials, this material has extremely low gas‐permeable porosity (16.5 m 2 g −1 ) in contrast to the high ionic accessibility. All these structural features collectively contribute to the high capacitances up to 732 F cm −3 , combined with small structural swelling at as low as 4.8% and good stability. At a discharge time of 6 s, the thin‐film intercalation electrode delivers an energy density of 24 mWh cm −3 , which universally outperforms the surface‐dominant capacitive processes in porous carbons.