In this work, an ultra-high stability polyaniline that retained 100% of its initial capacitance after 45 000 cycles was developed by designing and fabricating a ternary composite carbon nanotube/ethylvinylacetate/polyaniline (PANI/CNT/EVA) with a 3D co-continuous phase structure. The areal specific capacity of the PANI/CNT/EVA composite increased with increasing thickness. These findings hold great promise for the development of shape-conformable energy-storage devices.