Amorphous modified silyl-terminated 3D polymer electrolyte for high-performance lithium metal battery

Polymer electrolyte has been considered to eliminate the safety issue that caused by the lithium dendrite growth in the liquid electrolyte for the high-energy lithium metal battery. However, the practical applications of polymer electrolyte are still impeded by the low Li ionic conductivity, weak interfacial compatibility, low thermal stability and narrow electrochemical window. In this study, we have proposed a novel modified silylterminated polyether based polymer electrolyte by a cross-linking fabrication method. With a three-dimensional network structure, the amorphous polymer electrolyte has high ionic conductivity (similar to 0.36 mS cm(-1)) at room temperature, much higher thermal stability (T-m = 379 degrees C), high lithium ion transference number (similar to 0.65), stable electrochemical window up to 5.0 V (vs. Li+/Li) and an excellent compatibility to the electrode. With LiFePO4 cathode and this polymer electrolyte, the lithium metal battery delivers the high specific capacity of similar to 130 mA h g(-1) at 1 C rate over 300 cycles, and similar to 105 mA h g(-1) at 3 C rate with a superb cycling stability over 600 cycles at room temperature. We believe that this polymer electrolyte is a promising candidate for the practical applications and brings a new way to develop the high performance electrolyte for the lithium metal battery.