A potential approach for sustainable waste management of the spent battery material (SBM) is established for manufacturing conductive polyaniline (PANI) nanocomposites as electrode materials for supercapacitors, following the principle of "What comes from the power should be used for the power". The ternary nanocomposites (G/MnO2/PANI) containing PANI, graphite powder (G) and remanent MnO2 nanoparticles and the binary nanocomposites of polyaniline and graphite powder (G/PANI) are synthesized by the chemical oxidative polymerization of aniline in hydrochloric aqueous solution with the MnO2 nanoparticles in the spent battery powder (SBP) as oxidant. The WAN' sample, which was prepared with MnO2/aniline mole ratio of 1:1 with 1.0 mL aniline in 50 mL of 1.0 mol L-1 HCI, exhibits the electrical conductivity of 22.22 S cm(-1), the highest specific capacitance up to 317 g(-1) and the highest energy density of 31.0 Wh kg(-1), with retention of as high as 84.6% of its initial capacitance after 1000 cycles, indicating good cyclic stability. (C) 2016 Elsevier B.V. All rights reserved.