In-situ polymerization induced phase separation to develop high-performance self-healable polymeric electrolytes for lithium metal battery

The polymer electrolytes have become widely reported solid electrolytes in high-energy lithium metal batteries. However, this kind of electrolytes are limited by their tradeoff between ionic conductivity and mechanical strength. In addition, polymer electrolytes usually suffer from cracks or breakage due to the rigid structure. Therefore, these drawbacks have greatly influenced their practical applications in lithium metal batteries. Herein, we developed a novel self-healable polymer electrolyte (SHPE) by in-situ polymerizing the mixture of butyl acrylate and 2-ureido-4-pyrimidinone (UPy) with plastic crystal succinonitrile (SN) and lithium bis (trifuoromethanesulfonyl) imide (LiTFSI), which were premixed to behave as deep eutectic solvent (DES) to enhance the ionic conductivity. We found that SHPE displayed 0.46 mS/cm at 30 & DEG;C and its electrochemical window was determined to be 4.7 V. While the low dose of UPy could provide quadruple hydrogen bond to endow the polymer electrolyte with good self-healing capability and increase the polymer mechanical strength. Therefore, the symmetrical Li/Li cell using this SHPE showed stable properties as long as 1400 h. The Li/LiFePO4 cell revealed good capacity retention (93.8%, 140.6 mAh/g) after 300 cycles at 0.2C. This work may provide a promising strategy to develop high-performance polymer electrolytes for lithium metal batteries. & COPY; 2023 Elsevier Ltd. All rights reserved.

Automated summary

In this study, a novel self-healable polymer electrolyte (SHPE) was developed by in-situ polymerizing a mixture of butyl acrylate and 2-ureido-4-pyrimidinone (UPy) with plastic crystal succinonitrile (SN) and lithium bis(trifuoromethanesulfonyl) imide (LiTFSI). The SHPE exhibited high ionic conductivity and mechanical strength, addressing the limitations of traditional polymer electrolytes and improving the practical performance of lithium metal batteries.