Niobium Nitride Nb4N5 as a New High‐Performance Electrode Material for Supercapacitors

Advanced Science

Houlei Cui²  Guilian Zhu²  Xiangye Liu¹  Fengxin Liu²  Yian Xie²  Chongyin Yang²  Tianquan Lin²  Hui Gu² 

[1] Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, China;CAS Key Laboratory of Materials for Energy Conversion and State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, China

关键词: areal capacitance;    cycling stability;    Nb4N5 nanochannels;    pseudocapacitance;    supercapacitors;   

DOI  :  10.1002/advs.201500126

来源: Wiley

【 摘 要 】

Abstract

Supercapacitors suffer either from low capacitance for carbon or derivate electrodes or from poor electrical conductivity and electrochemical stability for metal oxide or conducting polymer electrodes. Transition metal nitrides possess fair electrical conductivity but superior chemical stability, which may be desirable candidates for supercapacitors. Herein, niobium nitride, Nb₄N₅, is explored to be an excellent capacitive material for the first time. An areal capacitance of 225.8 mF cm⁻², with a reasonable rate capability (60.8% retention from 0.5 to 10 mA cm⁻²) and cycling stability (70.9% retention after 2000 cycles), is achieved in Nb₄N₅ nanochannels electrode with prominent electrical conductivity and electrochemical activity. Faradaic pseudocapacitance is confirmed by the mechanistic studies, deriving from the proton incorporation/chemisorption reaction owing to the copious +5 valence Nb ions in Nb₄N₅. Moreover, this Nb₄N₅ nanochannels electrode with an ultrathin carbon coating exhibits nearly 100% capacitance retention after 2000 CV cycles, which is an excellent cycling stability for metal nitride materials. Thus, the Nb₄N₅ nanochannels are qualified for a candidate for supercapacitors and other energy storage applications.

【 授权许可】

CC BY   
© 2015 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

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