Gelatin and borax were successfully used as cross-linkers to prepare a hydrogel composite. Herein, the hollow hydrogel of graphene/polyaniline nanotube/ZIF-67-nanocages (G/PANI-NT/ZNC) as a ternary composite has been synthesized and applied as the active materials of supercapacitors. Cubic ZNC was prepared using Cu2O cubic nanoparticles as a template through etching and precipitating processes. Accordingly, the ZNCs are uniformly placed on the G/PANI-NT network. The novelty of this work is the synthesis of a new G/PANI-NT/ZNC composite hydrogel with gelatin and borax as cross-linkers and without freeze-drying. The obtained hydrogel indicated a specific surface area (3.57 m2 g− 1) and can be utilized as the supercapacitor electrode. The G/PANI-NT/ZNC electrode has a capacitance of 62.10 C g− 1 at 10 mV s− 1. The specific capacitance of G/PANI-NT/ZNC was far superior to those of G/PANI-NT/Cu-Z (33.36 C g− 1) and G/PANI-NT/hydrogels (6.28 C g− 1). Furthermore, the G/PANI-NT/ZNC electrode showed 92.2% cycling stableness after 8000 cycles. This work has significant reference importance for directly using nanocages in the synthesis of hydrogels as electrode materials for supercapacitors. Furthermore, the symmetric supercapacitor device was also successfully fabricated on the lab scale using a PVA-Na2SO4 gel electrolyte system, indicating that good performance can be achieved for advanced energy storage devices.

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