Multi-walled carbon nanotubes and activated carbon composite material as electrodes for electrochemical capacitors

•Binder-free AC electrodes with very low equivalent series resistance.•MWCNTs work simultaneously as binder and additive for AC electrode preparation.•Simple and facile synthesis combining AC and MWCNT onto Ni3Al.•Highly electrochemical stable electrodes on neutral aqueous-based electrolytes.•Long lifespan electrochemical capacitor devices.