Two　nanostructured　electrode　materials　are　fabricated　and　used　to　construct　cost-effective　asymmetric　supercapacitors　(ASCs).　Hierarchical　nickel　cobalt　oxide　nanoarrays　(NCO-NA)　consisting　of　nanosheets　(NCO-NS)　or　nanowires　(NCO-NW)　are　uniformly　grown　on　Ni　foam　by　a　simple,　effective,　and　generally　applicable　method,　while　biowaste-derived　hierarchical　porous　carbon　(Bio-HPC)　with　an　interconnected　microstructure　is　fabricated　by　pretreatment　with　potassium　hydroxide　and　followed　by　direct　pyrolysis.　Considering　the　mass　of　NiCo　2　O　4　,　the　maximum　specific　capacitance　of　the　hierarchical　NCO-NS　and　NCO-NW　electrodes　are　2300　and　2333　F　g　-1　,　respectively,　and　the　specific　capacitance　of　the　Bio-HPC　electrode　is　253.9　F　g　-1　at　a　scan　rate　of　5　mV　s　-1　.　NCO-NA,　Bio-HPC,　a　piece　of　polypropylene　membrane,　and　30　wt　%　KOH　solution　are　assembled　into　a　high-performance,　low-cost　ASC　with　the　capability　of　rapidly　storing　electrical　energy.　The　NCO-NW//Bio-HPC　ASC　exhibits　a　higher　energy　density　compared　with　NCO-NS//Bio-HPC　ASC,　while　the　latter　shows　better　cycling　performance　(the　capacitance　still　remains　91.12%　after　2000　cycles).　©　2017　American　Chemical　Society.