Metal vanadates are exceptional for electrochemical energy storage, and their nanocomposites outperform traditional metal oxides. Incorporating bio-inspired components with advanced designs improves performance, benefiting Li-ion batteries (LIBs) and supercapacitors for sustainable energy storage solutions (ESS). Hydrated metal vanadates are promising for the ESS owing to their large capacity, structure, low cost, and abundant resources. We present a new Zn3(OH)2V2O7·2H2O/Betalains nanocomposites (ZVH@Bn NCs) utilizing natural betalain pigment for green energy devices such as LIBs and supercapacitors for the first time. This is achieved through one-step synthesis through a water-soluble betalain extract-assisted low-temperature hydrothermal method. The study details the enhanced features of the composite, including improvements in morphology, electrical, optical, and electrochemical properties, which enhance Li+ storage processes. Betalains, acting as a stabilizing and capping agent, enhance the charge storage mechanism by preventing surface oxidation. They improve electrical conductivity by facilitating faster charge transfer and lowering the band gap of the NCs. With a high potential window of 2.4 V, ZVH@Bn as a supercapacitor exhibited stable cyclic voltammograms even at high scan rates (10,000 mV/s). The highest energy density and power density were obtained to be 13.53 Wh/kg and 1114.9 W/kg, respectively. ZVH@Bn NCs serve as an anode material for energy storage in the form of LIBs, with an initial discharge capacity of 1200 mAh/g. The specific capacity was found to be 742 mAh/g, even after 100 cycles at a 0.1C rate. Their stability, eco-friendliness, and efficiency suggest suitability for reliable, sustainable energy storage applications.