Porous carbons with high specific surface area and high defect density have been prepared through direct carbonization of cattle bones without any additional activators and templates. Benefiting from self-activation induced by hydroxyapatites within the cattle bones, the high-defect porous carbons obtained at 1100°C (PC-1100) possess the high specific surface area (2096m2 g−1), largest mesopore volume (1.829cm3 g−1), a narrow mesopore size distribution centered at approximately 4.0nm and good electrical conductivity (5141Sm−1). Due to the synergistic effect of the defects and pores, PC-1100 as the anode for Li-ion battery exhibits a high reversible capacity of 1488mAhg−1 after 250 cycles at 1Ag−1 and 661mAhg−1 after 1500 cycles at 10Ag−1. Even at 30Ag−1, PC-1100 can still deliver a high reversible capacity of 281mAhg−1, showing superior lithium storage capability. Moreover, the symmetric supercapacitor based on the PC-1100 in neat EMIM-BF4 electrolyte delivers a high energy density of 109.9Whkg−1 at a power density of 4.4kWkg−1, and maintains an energy density of 65.0Whkg−1 even at an ultrahigh power density of 81.5kWkg−1, as well as a superior cycling performance (96.4% of the capacitance retention after 5000 cycles).