Stabilizing the Solid‐Electrolyte Interphase with Polyacrylamide for High‐Voltage Aqueous Lithium‐Ion Batteries
Abstract
The introduction of “water‐in‐salt” electrolyte (WiSE) concept opens a new horizon to aqueous electrochemistry that is benefited from the formation of a solid‐electrolyte interphase (SEI). However, such SEI still faces multiple challenges, including dissolution, mechanical damaging, and incessant reforming, which result in poor cycling stability. Here, we report a polymeric additive, polyacrylamide (PAM) that effectively stabilizes the interphase in WiSE. With the addition of 5 molar % PAM to 21 mol kg−1 LiTFSI electrolyte, a LiMn2O4∥L‐TiO2 full cell exhibits enhanced cycling stability with 86 % capacity retention after 100 cycles at 1 C. The formation mechanism and evolution of PAM‐assisted SEI was investigated using operando small angle neutron scattering and density functional theory (DFT) calculations, which reveal that PAM minimizes the presence of free water molecules at the anode/electrolyte interface, accelerates the TFSI− anion decomposition, and densifies the SEI.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Sep 12, 2021
- Source ID
- 10.1002/ange.202107252
Entities
People
- Elie Paillard
- Henrich Frielinghaus
- Jie Li
- Kang Xu
- Leilei Du
- Lester C. Barnsley
- Martin Winter
- Oleg Borodin
- Rui Wang
- Travis P. Pollard
- Xiaokang Ju
- Xin He
- Xu Hou
Organizations
- Australian Synchrotron
- European Commission
- Heinz Maier-Leibnitz Zentrum
- Polytechnic University of Milan
- Sichuan University
- United States Army Research Laboratory
- United States Department of Energy
- University of Münster