Open AccessCoating of NCM 851005 Cathode Material with Al0@Al2O3 and Subsequent Treatment with Anhydrous HF
Author(s) -
Arthur Martens,
Christoph Bolli,
Anke Hoffmann,
Christoph Erk,
Thilo Ludwig,
Mario El Kazzi,
Ulf Breddemann,
Petr Novák,
Ingo Krossing
Publication year - 2020
Publication title -
journal of the electrochemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.258
H-Index - 271
eISSN - 1945-7111
pISSN - 0013-4651
DOI - 10.1149/1945-7111/ab68d0
Subject(s) - coating , anhydrous , amorphous solid , materials science , cathode , layer (electronics) , nanoparticle , conductivity , chemical engineering , analytical chemistry (journal) , nuclear chemistry , chemistry , composite material , nanotechnology , crystallography , organic chemistry , engineering
The volatile alane (H 2 AlO t Bu) 2 decomposes into amorphous HAlO or Al 0 @Al 2 O 3 nanoparticles upon heating, depending on the time and temperature. By coating the Ni-rich cathode material NCM851005 with this compound, the NCM’s cycling stability and electric conductivity were increased. Thus, the coating not only yielded Al 0 @Al 2 O 3 nanoparticles but also, by reaction with surface Li 2 O/LiOH/Li 2 CO 3 , a Li + conductive LiAlO 2 layer. The coatings with 0.3 and 0.1 wt% (H 2 AlO t Bu) 2 , respectively, significantly reduced the resistance build-up to 70/115% after 280 cycles at 1 C (351% without coating). Upon treatment of the 0.3 wt% Al-coating with two equivalents of anhydrous HF, the Al 2 O 3 and LiAlO 2 parts were transformed into a Li[AlO(OH)F] layer, which yielded better capacity retention, retaining the low impedance build-up of only +120% (280 cycles at 1 C). This treatment, however, proved to have the same effect as simply reducing the amount of (H 2 AlO t Bu) 2 for the coating to 0.1%.