Black Phosphorus‐Based Lithium‐Ion Capacitor

Abstract Black phosphorus (BP) with high theoretical capacity has received attention in lithium‐ion capacitors (LICs). Nevertheless, it is difficult to introduce BP to LICs due to poor rate capability and cycling stability. In this study, we implement BP‐based LIC by introducing BP/C composite with improved above mentions problems. The composite exhibits capacities of 2156 and 1088 mAh g⁻¹ at 0.1 and 5.0 A g⁻¹, respectively, and good cycling stability over 1000 cycles. It is the results of improved electrical conductivity and mitigated volume expansion by embedded structure with BP in amorphous carbon and covalent bonding at interface. The LIC delivers maximum energy and power density of 178 Wh kg⁻¹ at 30 W kg⁻¹ and 3.0 kW kg⁻¹ at 65 Wh kg⁻¹, respectively, and capacitance retention of 85 % after 5000 cycles. The BP has been successfully introduced into LIC and has the ample potential for application in electric vehicles.