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Suppression of Aluminum Current Collector Dissolution by Protective Ceramic Coatings for Better High‐Voltage Battery Performance
Author(s) -
Heckmann Andreas,
Krott Manuel,
Streipert Benjamin,
Uhlenbruck Sven,
Winter Martin,
Placke Tobias
Publication year - 2017
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.201601095
Subject(s) - dissolution , aluminium , materials science , ceramic , battery (electricity) , current collector , current (fluid) , voltage , metallurgy , composite material , chemical engineering , electrical engineering , engineering , power (physics) , physics , quantum mechanics
Batteries based on cathode materials that operate at high cathode potentials, such as LiNi 0.5 Mn 1.5 O 4 (LNMO), in lithium‐ion batteries or graphitic carbons in dual‐ion batteries suffer from anodic dissolution of the aluminum (Al) current collector in organic solvent‐based electrolytes based on imide salts, such as lithium bis(trifluoromethanesulfonyl) imide (LiTFSI). In this work, we developed a protective surface modification for the Al current collector by applying ceramic coatings of chromium nitride (Cr x N) and studied the anodic Al dissolution behavior. By magnetron sputter deposition, two different coating types, which differ in their composition according to the CrN and Cr 2 N phases, were prepared and characterized by X‐ray diffraction, X‐ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and their electronic conductivity. Furthermore, the anodic dissolution behavior was studied by cyclic voltammetry and chronocoulometry measurements in two different electrolyte mixtures, that is, LiTFSI in ethyl methyl sulfone and LiTFSI in ethylene carbonate/dimethyl carbonate 1:1 (by weight). These measurements showed a remarkably reduced current density or cumulative charge during the charge process, indicating an improved anodic stability of the protected Al current collector. The coating surfaces after electrochemical treatment were characterized by means of SEM and XPS, and the presence or lack of pit formation, as well as electrolyte degradation products could be well correlated to the electrochemical results.