Electronic Supplementary Information
A bifunctional electrolyte additive for H2O/HF
scavenging and enhanced
graphite/LiNi0.5Co0.2Mn0.3O2 cell performance at a
high voltage
Rong Zhou,a Jianxing Huang,a Shaobo Lai,a Jiyang Li,a Feng Wang,a Zhiqiang Chen,a
Weiqing Lin,a Chao Li,a Jing Wang*a and Jinbao Zhao*a
a. State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative
Innovation Center of Chemistry for Energy Materials, College of Chemistry
and Chemical Engineering, Xiamen University, Xiamen 361005, China
E-mail: [email protected], [email protected]
Keywords: Electrolyte additive, N,N-diethylamino trimethylsilane, High voltage,
LiNi0.5Co0.2Mn0.3O2, H2O/HF scavenger, Lithium-ion batteries
Electronic Supplementary Material (ESI) for Sustainable Energy & Fuels.This journal is © The Royal Society of Chemistry 2018
2
Fig. S1 DFT-calculated reaction energies (kcal mol-1) for the self-decomposition of
neutral DEATMS to homolytic (Path 1) and heterolytic (Path 2) bond cleavage.
3
Fig. S2 31P NMR spectrum of the baseline electrolyte with 2000 ppm H2O stored at 55
°C for 6 days. The degradation products are OPF2OR (triplet, -15.9 ppm, 1JP-F = 945.8
Hz) and multiple OPF(OR)2 type compounds (doublets, -7.3 ppm, 1JP-F = 936.7 Hz; -
7.5 ppm, 1JP-F = 921.1 Hz).
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Fig. S3 Linear sweep voltammograms of electrolytes with and without 0.5% DEATMS
from OCV to 6 V vs. Li/Li+ at a scan rate of 0.1 mV s-1.
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Fig. S4 Cycling voltammograms of Li/graphite half cells with and without 0.5%
DEATMS from OCV to 0 V vs. Li/Li+ at a scan rate of 0.1 mV s-1.
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Fig. S5 Cycling performances of (a) Li/NCM523 cells in a voltage range of 3.0 ~ 4.5
V at 1 C rate (1C = 160 mA g-1) and (b) Li/graphite cells in a voltage range of 0 ~ 3.0
V at 0.2 C rate (1C = 370 mA g-1) with and without DEATMS.
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Fig. S6 XPS profiles of the surface elements on the NCM523 cathode after pre-cycling
at a high voltage with and without the DEATMS additive.
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Fig. S7 Coulombic efficiency of graphite/NCM523 cells with and without 0.5 wt.%
DEATMS operated at 25 in different voltage ranges between (a) 3.0 ~ 4.3 V and (b) °C
3.0 ~ 4.5 V.
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Fig. S8 Normalized Raman spectra of the cathodes in the pristine state and after cycling
between 3.0 ~ 4.5 V.
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Fig. S9 SEM images of the (a) fresh graphite anode and (b) high-voltage cycled graphite
anodes with the baseline electrolyte and (c) 0.5% DEATMS electrolyte.
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Fig. S10 XPS profiles of the surface elements on the graphite anode after 100 cycles at
a high voltage with and without the DEATMS additive.
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