Expeditious and controllable synthesis of micron flower-like architecture Cu7S4@LSC via Ni ions morphology confinement for asymmetric button supercapacitor

•Green activated carbon materials were prepared from (LSC)Longans shell carbon and (LCC)Longans core carbon.•By introducing Ni ions to the morphology of the prepared mesh-like network CuS2@LSC composites transforms into micron flower-like Cu7S4@LSC.•Cu7S4@LSC as a positive material and alpha-Fe2O3 as a negative material assemble water-system button asymmetric supercapacitors.•The maximum specific capacitance of 1431.1 f g − 1, a single BASC lights up the LED and keeps it for 10 min. Copper sulfide as a typical example of transition metal sulfides is of great significance for practical application. Owing to maintain the structural stability of the converted reactive anode materials to alleviate their inherent poor conductivity and low specific capacitance have been considered as the most promising supercapacitors materials. The stoichiometric ratio and crystal structure of CuS are very sensitive, hence, it is extraordinarily imperative to regulate the morphology via controllable Ni ion functionalization for pseudocapacitors. Herein, the morphology of the prepared irregular mesh-like network CuS2@LSC (Longans shell carbon) composites transforms into micron flower-like Cu7S4@LSC by effective surface modification strategies. Furthermore, the LCC (Longans core carbon) was successfully prepared with compound granular alpha-Fe2O3 as a negative material to assemble water-system Button Asymmetric Supercapacitors (BASC). Benefiting from the unique morphology design of the micron flower-like structure, the Cu7S4@LSC manifests exceptional remarkable storage performance. The maximum specific capacitance of 1431.1 F g − 1 at 1 A g − 1, with energy density of 42.47 Wh kg−1 at the power density was 800 W kg−1. Additionally, a single BASC lights up the LED and keeps it for 10 min. This demonstrates our study provides new strategy and insights of developing cost-effective, reliable and exceptional electrochemical performance asymmetric supercapacitor for auxiliary energy storage devices in a general sense.