Composition Modulation of Ionic Liquid Hybrid Electrolyte for 5 V Lithium-Ion Batteries

Chia-Jung Wu; Purna Chandra Rath; Jagabandhu Patra; Dominic Bresser; Stefano Passerini; Bharath Umesh; Quan-Feng Dong; Tai-Chou Lee; Jeng-Kuei Chang

doi:10.1021/acsami.9b12915

Composition Modulation of Ionic Liquid Hybrid Electrolyte for 5 V Lithium-Ion Batteries

ACS Appl Mater Interfaces. 2019 Nov 13;11(45):42049-42056. doi: 10.1021/acsami.9b12915. Epub 2019 Nov 4.

Authors

Chia-Jung Wu¹, Purna Chandra Rath², Jagabandhu Patra^{2

3}, Dominic Bresser^{4

5}, Stefano Passerini^{4

5}, Bharath Umesh⁶, Quan-Feng Dong⁷, Tai-Chou Lee¹, Jeng-Kuei Chang^{2

3

6}

Affiliations

¹ Department of Chemical and Materials Engineering , National Central University , 300 Jhong-Da Road , Taoyuan 32001 , Taiwan.
² Department of Materials Science and Engineering , National Chiao Tung University , 1001 University Road , Hsinchu 30010 , Taiwan.
³ Hierarchical Green-Energy Materials (Hi-GEM) Research Center , National Cheng Kung University , 1 University Road , Tainan 70101 , Taiwan.
⁴ Helmholtz Institute Ulm (HIU) , Helmholtzstrasse 11 , D-89081 Ulm , Germany.
⁵ Karlsruhe Institute of Technology (KIT) , P. O. Box 3640, 76021 Karlsruhe , Germany.
⁶ Institute of Materials Science and Engineering , National Central University , 300 Jhong-Da Road , Taoyuan 32001 , Taiwan.
⁷ State Key Laboratory for Physical Chemistry of Solid Surfaces, Department of Chemistry , Xiamen University , 422 Siming South Road , Xiamen 361005 , China.

PMID: 31633334
DOI: 10.1021/acsami.9b12915

Abstract

Electrolyte is a key component in high-voltage lithium-ion batteries (LIBs). Bis(trifluoromethanesulfonyl)imide-based ionic liquid (IL)/organic carbonate hybrid electrolytes have been a research focus owing to their excellent balance of safety and ionic conductivity. Nevertheless, corrosion of Al current collectors at high potentials usually happens for this kind of electrolyte. In this study, this long-standing problem is solved via the modulation of the IL/carbonate ratio and LiPF₆ concentration in the hybrid electrolyte. The proposed electrolyte suppresses Al dissolution and electrolyte oxidation at 5 V (vs Li⁺/Li) and thus allows for ideal lithiation/delithiation performance of a high-voltage LiNi_0.5Mn_1.5O₄ (LNMO) cathode even at 55 °C. The underlying mechanism is examined in this work. Excellent cycling stability (97% capacity retention) for an LNMO cathode after 300 cycles is achieved. This electrolyte shows good wettability toward a polyethylene separator and low flammability. In addition, satisfactory compatibility with both graphite and Si-based anodes is confirmed. The proposed electrolyte design strategies have great potential for applications in high-voltage LIBs.

Keywords: 5 V battery; Al corrosion; anode compatibility; electrolyte design; high safety.