Open AccessNiobium Nitride Nb 4 N 5 as a New High‐Performance Electrode Material for Supercapacitors
Author(s) -
Cui Houlei,
Zhu Guilian,
Liu Xiangye,
Liu Fengxin,
Xie Yian,
Yang Chongyin,
Lin Tianquan,
Gu Hui,
Huang Fuqiang
Publication year - 2015
Publication title -
advanced science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.388
H-Index - 100
ISSN - 2198-3844
DOI - 10.1002/advs.201500126
Subject(s) - supercapacitor , materials science , pseudocapacitance , nitride , capacitance , electrode , pseudocapacitor , electrochemistry , niobium , faraday efficiency , oxide , niobium nitride , chemical engineering , nanotechnology , metallurgy , chemistry , layer (electronics) , engineering
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, Nb 4 N 5 , 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 Nb 4 N 5 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 Nb 4 N 5 . Moreover, this Nb 4 N 5 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 Nb 4 N 5 nanochannels are qualified for a candidate for supercapacitors and other energy storage applications.