Pizza-like heterostructured Ti3C2T /Bi2S3@N-C with ultra-high specific capacitance as a potential electrode material for aqueous zinc-ion hybrid supercapacitors

• A new pizza-like ternary heterostructure Ti 3 C 2 T x /Bi 2 S 3 @N-C was fabricated by in-situ growth. • The introduction of dopamine has played an important role in the construction of the ternary composite material. • Ti 3 C 2 T x /Bi 2 S 3 @N-C delivered high specific capacitance of 653 F g -1 at 1 A g -1 in three electrode system. • Ti 3 C 2 T x /Bi 2 S 3 @N-C served as electrode material both for SSC and ZIHC and showed energy density of 46.98 W h kg -1 in ZIHC. The aqueous zinc-ion hybrid supercapacitor (ZIHC) has become an emerging energy storage device due to its safety and low cost. Herein, a new pizza-like heterostructure of Ti 3 C 2 T x intercalated by N-doped-carbon-wrapped Bi 2 S 3 is fabricated by in-situ growth. The specific capacitance of Ti 3 C 2 T x /Bi 2 S 3 @N-C electrode is as high as 653 F g −1 at 1 A g −1 , which is significantly higher than other binary composites or similar MXene-based materials in literature. The ZIHC are assembled with Ti 3 C 2 T x /Bi 2 S 3 @N-C and Zn foil as electrodes, possessing high specific capacitance of 150.33 F g −1 at 1 A g −1 , and a maximum energy density of 46.98 W h kg −1 at a power density of 750 W kg −1 . The excellent performance of Ti 3 C 2 T x /Bi 2 S 3 @N-C is mainly attributed to the synergistic effect of the three components: (a) highly conductive Ti 3 C 2 T x as the substrate shortens the electron transport path; (b) the in-situ growth of Bi 2 S 3 on Ti 3 C 2 T x layers makes full use of Bi 2 S 3 active sites; (c) the innovative introduction of dopamine can not only make Bi(NO) 3 evenly dispersed, but also form the “cross-bridge” N-C film, which further improves the binding between Ti 3 C 2 T x substrate and Bi 2 S 3 and reduces the internal resistance greatly. This study proposes a new in-situ growth strategy for a ternary heterostructure, which may offer a new avenue for the development of high-performance electrode materials.