Stabilizing the Li1.3 Al0.3 Ti1.7 (PO4 )3 |Li Interface for High Efficiency and Long Lifespan Quasi-Solid-State Lithium Metal Batteries

Zhen Chen; Dominik Stepien; Fanglin Wu; Maider Zarrabeitia; Hai-Peng Liang; Jae-Kwang Kim; Guk-Tae Kim; Stefano Passerini

doi:10.1002/cssc.202200038

Stabilizing the Li_1.3 Al_0.3 Ti_1.7 (PO₄ )₃ |Li Interface for High Efficiency and Long Lifespan Quasi-Solid-State Lithium Metal Batteries

ChemSusChem. 2022 May 20;15(10):e202200038. doi: 10.1002/cssc.202200038. Epub 2022 Apr 22.

Authors

Zhen Chen^{1

2}, Dominik Stepien^{1

2}, Fanglin Wu^{1

2}, Maider Zarrabeitia^{1

2}, Hai-Peng Liang^{1

2}, Jae-Kwang Kim³, Guk-Tae Kim^{1

2}, Stefano Passerini^{1

2}

Affiliations

¹ Helmholtz Institute Ulm (HIU), Helmholtzstrasse 11, 89081, Ulm, Germany.
² Karlsruhe Institute of Technology (KIT), P.O. Box 3640, 76021, Karlsruhe, Germany.
³ Department of Energy Convergence Engineering, Cheongju University, Chungbuk 28503, Cheongju, Republic of Korea.

Abstract

To tackle the poor chemical/electrochemical stability of Li_1+x Al_x Ti_2-x (PO₄ )₃ (LATP) against Li and poor electrode|electrolyte interfacial contact, a thin poly[2,3-bis(2,2,6,6-tetramethylpiperidine-N-oxycarbonyl)norbornene] (PTNB) protection layer is applied with a small amount of ionic liquid electrolyte (ILE). This enables study of the impact of ILEs with modulated composition, such as 0.3 lithium bis(fluoromethanesulfonyl)imide (LiFSI)-0.7 N-butyl-N-methylpyrrolidinium bis(fluoromethanesulfonyl)imide (Pyr₁₄ FSI) and 0.3 LiFSI-0.35 Pyr₁₄ FSI-0.35 N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (Pyr₁₄ TFSI), on the interfacial stability of PTNB@Li||PTNB@Li and PTNB@Li||LiNi_0.8 Co_0.1 Mn_0.1 O₂ cells. The addition of Pyr₁₄ TFSI leads to better thermal and electrochemical stability. Furthermore, Pyr₁₄ TFSI facilitates the formation of a more stable Li|hybrid electrolyte interface, as verified by the absence of lithium "pitting corrosion islands" and fibrous dendrites, leading to a substantially extended lithium stripping-plating cycling lifetime (>900 h). Even after 500 cycles (0.5C), PTNB@Li||LiNi_0.8 Co_0.1 Mn_0.1 O₂ cells achieve an impressive capacity retention of 89.1 % and an average Coulombic efficiency of 98.6 %. These findings reveal a feasible strategy to enhance the interfacial stability between Li and LATP by selectively mixing different ionic liquids.

Keywords: batteries; electrolytes; interfacial stability; ionic liquids; lithium.

Abstract

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