Simultaneous Formation of Interphases on both Positive and Negative Electrodes in High‐Voltage Aqueous Lithium‐Ion Batteries
Abstract
The formation of solid‐electrolyte interphase (SEI) in “water‐in‐salt” electrolyte (WiSE) expands the electrochemical stability window of aqueous electrolytes beyond 3.0 V. However, the parasitic hydrogen evolution reaction that drives anode corrosion, cracking, and the subsequent reformation of SEI still occurs, compromising long‐term cycling performance of the batteries. To improve cycling stability, an unsaturated monomer acrylamide (AM) is introduced as an electrolyte additive, whose presence in WiSE reduces its viscosity and improves ionic conductivity. Upon charging, AM electropolymerizes into polyacrylamide, as confirmed both experimentally and computationally. The in situ polymer constitutes effective protection layers at both anode and cathode surfaces, and enables LiMn2O4||L‐TiO2 full cells with high specific capacity (157 mAh g−1 at 1 C), long‐term cycling stability (80% capacity retention within 200 cycles at 1 C), and high rate capability (79 mAh g−1 at 30 C). The in situ electropolymerization found in this work provides an alternative and highly effective strategy to design protective interphases at the negative and positive electrodes for high‐voltage aqueous batteries of lithium‐ion or beyond.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Dec 01, 2021
- Source ID
- 10.1002/smll.202104986
Entities
People
- Elie Paillard
- Hai Lin
- Jie Li
- Jun Wang
- Kang Xu
- Leilei Du
- Martin Winter
- Oleg Borodin
- Travis P. Pollard
- Wenguang Zhao
- Xiaokang Ju
- Xin He
- Xu Hou
Organizations
- Peking University Shenzhen Graduate School
- Polytechnic University of Milan
- Sichuan University
- United States Army Research Laboratory
- University of Münster