<p>The present study investigates the synthesis and performance of PLA and NiFe₂O₄ NP composite electrodes towards enhancing energy storage capacity and mechanical flexibility for wearable electronics of the future. XRD validated the inclusion of NiFe₂O₄ with typical peaks and nanoscale crystallite size. FTIR evidenced metal–oxygen vibrations and NiFe₂O₄/PLA interactions. SEM indicated the uniform dispersion of NiFe₂O₄ within PLA matrix. XPS validated Ni²⁺, Fe³⁺, and O²⁻ states, confirming integration success. WCA analysis exhibited enhanced hydrophilicity with an increase in the content of NiFe₂O₄, with 1.5 wt% providing the best wettability. Cyclic voltammetry indicated increased redox activity with increasing content of NiFe₂O₄, and the highest capacitance was found at 1.5 wt% film. Electrochemical impedance spectroscopy indicated lower charge transfer resistance at 1.5 wt%, which pointed to better conductivity. Galvanostatic charge–discharge tests indicated improved cycling stability and greater specific capacitance at this composition. In general, the best electrochemical performance was offered by 1.5 wt% of NiFe₂O₄/PLA. The composite electrodes had a high specific capacitance of 62.9 F/g at a current density of 0.1 A/g. They also had a power density of 505.1 W/kg and an energy density of 22.3 Wh/kg, which shows that they can store and recover energy well. They also showed good cyclic stability by retaining 86% of their initial capacitance after 5000 charge–discharge cycles, indicating durability for long-term use. In addition, the NiFe₂O₄/PLA composite showed significant antibacterial activity against <i>Staphylococcus aureus</i> and <i>Escherichia coli</i>, showing its applicability as an antimicrobial material. These results show that the synthesized electrodes can be used in high-performance energy storage devices that also have built-in hygiene features.</p>