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Formation of a Surficial Bifunctional Nanolayer on Nb 2 O 5 for Ultrastable Electrodes for Lithium‐Ion Battery
Author(s) -
Cheong Jun Young,
Kim Chanhoon,
Jung JiWon,
Yoon Ki Ro,
Cho SuHo,
Youn DooYoung,
Jang HyeYeon,
Kim IlDoo
Publication year - 2017
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.201603610
Subject(s) - materials science , lithium (medication) , bifunctional , electrode , electrochemistry , nanotechnology , niobium , battery (electricity) , chemical engineering , conductivity , nanoparticle , metallurgy , catalysis , chemistry , medicine , biochemistry , power (physics) , physics , quantum mechanics , engineering , endocrinology
Safe and long cycle life electrode materials for lithium‐ion batteries are significantly important to meet the increasing demands of rechargeable batteries. Niobium pentoxide (Nb 2 O 5 ) is one of the highly promising candidates for stable electrodes due to its safety and minimal volume expansion. Nevertheless, pulverization and low conductivity of Nb 2 O 5 have remained as inherent challenges for its practical use as viable electrodes. A highly facile method is proposed to improve the overall cycle retention of Nb 2 O 5 microparticles by ammonia (NH 3 ) gas‐driven nitridation. After nitridation, an ultrathin surficial layer (2 nm) is formed on the Nb 2 O 5 , acting as a bifunctional nanolayer that allows facile lithium (Li)‐ion transport (10–100 times higher Li diffusivity compared with pristine Nb 2 O 5 microparticles) and further prevents the pulverization of Nb 2 O 5 . With the subsequent decoration of silver (Ag) nanoparticles (NPs), the low electric conductivity of nitridated Nb 2 O 5 is also significantly improved. Cycle retention is greatly improved for nitridated Nb 2 O 5 (96.7%) compared with Nb 2 O 5 (64.7%) for 500 cycles. Ag‐decorated, nitridated Nb 2 O 5 microparticles and nitridated Nb 2 O 5 microparticles exhibit ultrastable cycling for 3000 cycles at high current density (3000 mA g −1 ), which highlights the importance of the surficial nanolayer in improving overall electrochemical performances, in addition to conductive NPs.