Non-polar ether-based electrolyte solutions for stable high-voltage non-aqueous lithium metal batteries

Zheng Li; Harsha Rao; Rasha Atwi; Bhuvaneswari M Sivakumar; Bharat Gwalani; Scott Gray; Kee Sung Han; Thomas A Everett; Tanvi A Ajantiwalay; Vijayakumar Murugesan; Nav Nidhi Rajput; Vilas G Pol

doi:10.1038/s41467-023-36647-1

Non-polar ether-based electrolyte solutions for stable high-voltage non-aqueous lithium metal batteries

Nat Commun. 2023 Feb 16;14(1):868. doi: 10.1038/s41467-023-36647-1.

Authors

Zheng Li¹, Harsha Rao², Rasha Atwi³, Bhuvaneswari M Sivakumar⁴, Bharat Gwalani^{4

5}, Scott Gray⁶, Kee Sung Han^{4

5}, Thomas A Everett⁷, Tanvi A Ajantiwalay⁴, Vijayakumar Murugesan^{4

5}, Nav Nidhi Rajput³, Vilas G Pol⁸

Affiliations

¹ Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN, 47907, USA. li3259@purdue.edu.
² Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN, 47907, USA.
³ Department of Materials Science and Chemical Engineering, Stony Brook University, Stony Brook, NY, 11794, USA.
⁴ Pacific Northwest National Laboratory, Richland, WA, 99352, USA.
⁵ The Joint Center for Energy Storage Research, Pacific Northwest National Laboratory, Richland, WA, 99352, USA.
⁶ Battery Innovation Center, Newberry, IN, 47449, USA.
⁷ Discovery Park, Purdue University, West Lafayette, IN, 47907, USA.
⁸ Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN, 47907, USA. vpol@purdue.edu.

Abstract

The electrochemical instability of ether-based electrolyte solutions hinders their practical applications in high-voltage Li metal batteries. To circumvent this issue, here, we propose a dilution strategy to lose the Li⁺/solvent interaction and use the dilute non-aqueous electrolyte solution in high-voltage lithium metal batteries. We demonstrate that in a non-polar dipropyl ether (DPE)-based electrolyte solution with lithium bis(fluorosulfonyl) imide salt, the decomposition order of solvated species can be adjusted to promote the Li⁺/salt-derived anion clusters decomposition over free ether solvent molecules. This selective mechanism favors the formation of a robust cathode electrolyte interphase (CEI) and a solvent-deficient electric double-layer structure at the positive electrode interface. When the DPE-based electrolyte is tested in combination with a Li metal negative electrode (50 μm thick) and a LiNi_0.8Co_0.1Mn_0.1O₂-based positive electrode (3.3 mAh/cm²) in pouch cell configuration at 25 °C, a specific discharge capacity retention of about 74% after 150 cycles (0.33 and 1 mA/cm² charge and discharge, respectively) is obtained.