S.Q. Jiang+, F.F. Xing+, J.C. Zhang, L.X. Xiang, Q. Li, F.G. Xu, Z.-S. Wu*, and Y.Y. Mai*
Chemical Engineering Journal, 2023, 452, 139095.

DOI: 10.1016/j.cej.2022.139095 [PDF]

Lithium-ion capacitors (LICs) are distinguished for bridging the gap of energy and power densities between lithium-ion batteries and supercapacitors. However, the kinetic mismatch between the slow diffusion and fast adsorption/desorption of lithium ions usually leads to the sacrifice of high power density or high energy density.Here, we report a general “one-for-two” strategy for controllable construction of 2D mesoporous polydopamine/reduced-graphene-oxide heterostructure (mPDA/rGO) with ordered in-plane cylindrical mesochannels as cathode and mPDA/rGO derived nitrogen-doped carbon nanosheets (mNC/rGO) as anode of LICs to achieve fast electrochemical kinetics.The in-plane cylindrical mesochannels and surface redox reactions of 2D mPDA/rGO andmNC/rGOensure rapid reaction kinetics in both cathode and anode. As a result, mPDA/rGO show remarkable specific capacity of 133 mAh g^-1, and excellent rate capability of 94 mAh g^-1even at 5 A g^-1. Meanwhile, 2D mNC/rGO exhibits high capacitance of 550 mAh g^-1at 0.1 A g^-1and 225 mAh g^-1at 5 A g^-1. The as-assembled LICs with these two electrodes offer a high energy density of 208 Wh kg^-1at a power density of 176 W kg^-1, which can retain as high as 102.2 Wh kg^-1at 8.8 kW kg^-1.This study demonstrates the control of porosity and morphology as an appealing strategy for rational construction of 2D electrode materials to boost high-energy and high-power LICs.