FeNb2O6/reduced graphene oxide composites with intercalation pseudo-capacitance enabling ultrahigh energy density for lithium-ion capacitors

Shuying Kong; Xu Zhang; Binbin Jin; Xiaogang Guo; Guoqing Zhang; Huisheng Huang; Xinzhu Xiang; Kui Cheng

doi:10.1039/d1ra03198h

FeNb₂O₆/reduced graphene oxide composites with intercalation pseudo-capacitance enabling ultrahigh energy density for lithium-ion capacitors

RSC Adv. 2021 Nov 10;11(51):32248-32257. doi: 10.1039/d1ra03198h. eCollection 2021 Sep 27.

Authors

Shuying Kong¹, Xu Zhang², Binbin Jin¹, Xiaogang Guo¹, Guoqing Zhang¹, Huisheng Huang¹, Xinzhu Xiang¹, Kui Cheng³

Affiliations

¹ Chongqing Key Laboratory of Inorganic Special Functional Materials, College of Chemistry and Chemical Engineering, Yangtze Normal University Chong Qing 404100 China kongshuying@126.com.
² School of Materials Science and Engineering, Ningxia Research Center of Silicon Target and Silicon-Carbon Negative Materials Engineering Technology, North Minzu University Yinchuan 750021 China.
³ College of Engineering, Northeast Agricultural University Harbin 150030 China chengkui@hrbeu.edu.cn.

Abstract

Lithium-ion capacitors (LICs), which combine the characteristics of lithium-ion batteries and supercapacitors, have been well studied recently. Extensive efforts are devoted to developing fast Li⁺ insertion/deintercalation anode materials to overcome the discrepancy in kinetics between battery-type anodes and capacitive cathodes. Herein, we design a FeNb₂O₆/reduced graphene oxide (FNO/rGO) hybrid material as a fast-charge anode that provides a solution to the aforementioned issue. The synergetic combination of FeNb₂O₆, whose unique structure promotes fast electron transport, and highly conductive graphene shortens the Li⁺ diffusion pathways and enhances structural stability, leading to excellent electrochemical performance of the FNO/rGO anode, including a high capacity (770 mA h g^-1 at 0.05 A g^-1) and long cycle stability (95.3% capacitance retention after 500 cycles). Furthermore, the FNO/rGO//ACs LIC achieves an ultrahigh energy density of 135.6 W h kg^-1 (at 2000 W kg^-1) with a wide working potential window from 0.01 to 4 V and remarkable cycling performance (88.5% capacity retention after 5000 cycles at 2 A g^-1).