Porous carbon electrodes with battery-capacitive storage features for high performance Li-ion capacitors

Li-ion capacitors (LICs) are considered one of the most promising energy storage devices due to their integrated battery and capacitor characteristics. Herein, we demonstrate a green and facile strategy to synthesize high-defect mesopore-dominant porous carbon (referred to as HDMPC) through direct pyrolysis of low-cost sheep bone in an Ar atmosphere. The HDMPC possesses large specific surface area (2192 m(2) g(-1)) and high proportion of mesopore (98.0%, accounted by pore volume), as well as numerous intrinsic defects and heteroatom-induced defects. The high defect density and unique porosity endow HDMPC electrodes with battery-capacitive storage features, which show high reversible capacity, good rate capability and long cycling performance as anode and cathode in half-cells (using metallic Li as counter electrode). Moreover, for the first time, we use the HDMPCs both as anode and cathode materials to assemble LIC. The HDMPC||HDMPC LIC can deliver integrated high energy density (106.4 Wh kg(-1)) and power density (88.8 kW kg(-1)), as well as a superior cycling performance with a capacitance retention of 88.3% after 8000 cycles at the current density of 2 A g(-1).