High-Performance Lithium-Ion Capacitors Based on 3D Interconnected Nitrogen-Doped Ultrathin Carbon Frameworks with Encapsulated Fe₂O₃ Nanoparticles

Abstract

The mismatch of capacity and electrochemical reaction kinetics between capacitor-type and battery-type electrodes caused by the charge-storage mechanism hinders the development of lithium-ion capacitors (LICs). To relieve the above contradiction, a 3D interconnected nitrogen-doped ultrathin carbon (3DNC) framework encapsulated with Fe 2 O 3 (3DNC@ Fe 2 O 3 -700) was prepared and applied as the anode and cathode to fabricate symmetric LICs. The 3DNC framework can provide a stable structure, short electron transport length, and abundant active sites. Besides, the encapsulated nanoparticles (NPs) can enhance the capacity of the anode and, meanwhile, maintain the excellent cycling performance owing to the relatively strong interaction and abundant interface between 3DNC and Fe 2 O 3 NPs. Benefiting from the unique properties, 3DNC@Fe 2 O 3 -700 anode exhibits a capacity of 946.6 mA h g −1 and a retention rate of 106.5% after 5000 cycles. 3DNC@Fe 2 O 3 -700 cathode displays a capacity of 82.1 mA h g −1 and a retention rate of 100% after 5000 cycles. 3DNC@Fe 2 O 3 -700//3DNC@Fe 2 O 3 -700 LICs show a superior performance of high energy density of 206 W h kg −1 at 226 W kg −1 and a capacity retention of 118.2% after 5000 cycles at 1 A g −1 . This work may provide a route to relieve the mismatch between the anode and cathode for high-performance symmetric LICs.

Insights into Formation and Li‐Storage Mechanisms of Hierarchical Accordion‐Shape Orthorhombic CuNb2O6 toward Lithium‐Ion Capacitors as an Anode‐Active Material

“…While the kinetic difference between the cathode and anode, due to the sluggish Li + insertion/extraction and rapid adsorption/desorption of anions, serious effects the overall performance of LICs. [7][8][9][10] Accordingly, it is still a critical challenge to improve the intrinsic rate properties of anode materials toward advanced LICs.…”

Fe2O3 Embedded in N-Doped Porous Carbon Derived from Hemin Loaded on Active Carbon for Supercapacitors

“…Fe 2 O 3 has been deemed an ideal electrode material for SCs due to its abundant resources, environmental benignity, and intrinsic pseudocapacitive properties [ 17 , 18 , 19 ]. Additionally, the Fe 2 O 3 nanostructure facilitates electrochemical reactions and enlarges the electrochemical capacity contribution ratio by releasing the volume change [ 20 , 21 ]. Previous results [ 22 , 23 ] suggest that the expected electrochemical performance cannot be simply obtained with the physical mixing of Fe 2 O 3 and carbon.…”

Li-Ni Metal Oxides Processed with Rapid Atmospheric-Pressure-Plasma Jet for Flexible Gel-Electrolyte Li-Ion Hybrid Supercapacitors

“…In addition to using composite materials, both symmetrical and asymmetrical electrode assembly are notable features of HSC. [32][33][34][35][36] Various lithium transition metal oxides such as LiCoO 2 , LiNiO 2 , and LiMnO 2 have been investigated for use in HSCs. 37 Among them, LiNiO 2 has a higher discharge capacity and lower cost and is more ecofriendly than LiCoO 2 .…”