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Investigation of Dimethyl Carbonate and Propylene Carbonate Mixtures for LiNi 0.6 Mn 0.2 Co 0.2 O 2 ‐Li 4 Ti 5 O 12 Cells
Author(s) -
Björklund Erik,
Göttlinger Mara,
Edström Kristina,
Brandell Daniel,
Younesi Reza
Publication year - 2019
Publication title -
chemelectrochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.182
H-Index - 59
ISSN - 2196-0216
DOI - 10.1002/celc.201900672
Subject(s) - ethylene carbonate , propylene carbonate , electrolyte , dimethyl carbonate , electrochemistry , carbonate , lithium (medication) , dissolution , x ray photoelectron spectroscopy , inorganic chemistry , materials science , context (archaeology) , chemical engineering , chemistry , electrode , methanol , organic chemistry , metallurgy , medicine , paleontology , biology , engineering , endocrinology
Abstract It has recently been shown that ethylene carbonate (EC) experience poor stability at high potentials in lithium‐ion batteries, and development of electrolytes without EC, not least using ethyl methyl carbonate (EMC), has therefore been suggested in order to improve the capacity retention. In this context, we here explore another alternative electrolyte system consisting of propylene carbonate (PC) and dimethyl carbonate (DMC) mixtures in NMC‐LTO (LiNi 0.6 Mn 0.2 Co 0.2 O 2 , Li 4 Ti 5 O 12 ) cells cycled up to 2.95 V. While PC experience wettability problems and DMC has difficulties dissolving LiPF 6 salt, blends between these could possess complementary properties. The electrolyte blend showed superior cycling performance at sub‐zero temperatures compared to EC‐containing counterparts. At 30 °C, however, the PC‐DMC electrolyte did not show any major improvement in electrochemical properties for the NMC‐LTO cell chemistry. Photoelectron spectroscopy measurements showed that thin surface layers were detected on both NMC (622) and LTO electrodes in all investigated electrolytes. The results suggest that both PC and EC will react on the electrodes, but with EC forming thinner layers comprising more carbonates. Moreover, the electrochemical stability at high electrochemical potentials is similar for the studied electrolytes, which is surprising considering that most are free from the reactive EC component.