Affiliation:
1. Beijing Key Laboratory of Environmental Science and Engineering School of Materials Science and Engineering Beijing Institute of Technology Beijing 100081 China
2. Advanced Technology Research Institute Beijing Institute of Technology Jinan 250300 China
3. School of Chemical Engineering University of Chinese Academy of Sciences Beijing 100049 China
4. Collaborative Innovation Center of Electric Vehicles in Beijing Beijing 100081 China
Abstract
AbstractThe unstable interface between Li metal and ethylene carbonate (EC)‐based electrolytes triggers continuous side reactions and uncontrolled dendrite growth, significantly impacting the lifespan of Li metal batteries (LMBs). Herein, a bipolar polymeric protective layer (BPPL) is developed using cyanoethyl (−CH2CH2C≡N) and hydroxyl (−OH) polar groups, aiming to prevent EC‐induced corrosion and facilitating rapid, uniform Li+ ion transport. Hydrogen‐bonding interactions between −OH and EC facilitates the Li+ desolvation process and effectively traps free EC molecules, thereby eliminating parasitic reactions. Meanwhile, the −CH2CH2C≡N group anchors TFSI− anions through ion‐dipole interactions, enhancing Li+ transport and eliminating concentration polarization, ultimately suppressing the growth of Li dendrite. This BPPL enabling Li|Li cell stable cycling over 750 cycles at 10 mA cm−2 for 2 mAh cm−2. The Li|LiNi0.8Mn0.1Co0.1O2 and Li|LiFePO4 full cells display superior electrochemical performance. The BPPL provides a practical strategy to enhanced stability and performance in LMBs application.
Funder
National Key Research and Development Program of China
Key Technology Research and Development Program of Shandong Province
National Natural Science Foundation of China