▎ 摘　　要

Developing lithium ion capacitors (LICs) with high energy density is still challenging, due to the kinetic mismatch between the capacitor-type cathode and the battery-type anode. In addition, metal-free LICs are preferred over high-cost and unsustainable metal-containing electrode materials. Exploring appropriate metal-free cathode and anode materials with high capacity and excellent rate performance is one of the keys to attain such goal. Herein, nanoarchitectured graphene-based LICs are successfully constructed by using 2D polydopamine-graphene heterostructured anode and porous graphene cathode. The 2D nature of polydopamine-graphene facilitate the transport of electrolyte ions while graphene promotes electron transfer. The high specific surface area of the porous graphene endows ions with accessibility and fast transport. The metal-free LIC device achieves a high energy density (135.6 Wh kg(-1) at 210.4 W kg(-1)), high power density (21.0 kW kg(-1) at 78.9 Wh kg(-1)), high low-temperature perfor-mance (76.4 Wh kg(-1) at-20 degrees C), and reasonably long cycling life. This work provides an effective strategy to design metal-free LIC with high performance at wide temperature range. (C) 2020 Published by Elsevier Ltd.