Self‐Assembled Binary Organic Granules with Multiple Lithium Uptake Mechanisms toward High‐Energy Flexible Lithium‐Ion Hybrid Supercapacitors

Abstract

Abstract Lithium‐ion hybrid supercapacitors (Li‐HSCs), by virtue of synergizing the merits of batteries and supercapacitors, have attracted considerable attention for high‐energy/‐power energy storage applications. Inorganic transition‐metal compounds with pseudocapacitive characteristics have been widely investigated as promising anodes for use in advanced Li‐HSCs. Nevertheless, the concept of using eco‐friendly and naturally abundant organic compounds as anodes for Li‐HSCs has rarely been realized so far, due to their inferior electrical and ionic conductivity and low capacitive activity. Herein, an innovative self‐assembly strategy to synthesize uniform binary organic granules as high‐capacitive and durable anodes for the construction of high‐energy flexible Li‐HSCs is reported. The unique architecture of maleic acid@polyvinylidene fluoride (MA@PVDF) granules consisting of ultrafine MA nanocrystals within a PVDF network offers multiple lithium storage mechanisms including two‐electron lithiation/delithiation, Li + ‐ion intercalation/deintercalation within the MA (020) planes, and Li + ‐ion adsorption/desorption at the MA nanocrystals/electrolyte interface. The as‐constructed 4.3 V Li‐HSC full cell comprising a MA@PVDF anode and an activated carbon cathode delivers high energy/power densities (158.4 Wh kg −1 /107.5 W kg −1 and 70.9 Wh kg −1 /10750 W kg −1 ), outperforming those of organic anode–based Li/Na‐HSCs and the state‐of‐the‐art inorganic hybrid capacitors. The deriving prototype flexible Li‐HSC devices manifest exceptional energy output under various deformed conditions and bent–release cycling.