Comparing with traditional salt-in-polymer systems, single-ion conducting polymer electrolytes (SICPEs) have the great potential for improved electrochemical performance according to numerous computational and several experimental demonstrations. However, up to date, the reported SICPEs still far from the practical solid electrolyte, including low current density and short battery lifetime. Herein, the rational designed, nonconventional SICPEs are demonstrated by in-situ copolymerization of vinyl ethylene carbonate (VEC) and lithium (4-styrenesulfonyl)(trifluoromethanesulfonyl)imide (LiSTFSI) monomers. The designed SICPEs exhibit improved Li-ion transference numbers, tolerance of high current density, high voltage stability, and broad operation temperatures. At room temperature, the symmetrical cell using the SICPE with mole ratio of LiSTFSI and VEC being 1:10, i.e., Li/poly(VEC-r-LiSTFSI10)/Li cell, achieves stable cycling performance over 3000 h at 3 mA cm-2 and more than 1000 h even at ultrahigh current density of 10 mA cm-2. A remarkable stable battery performance till 1200 cycles at 1 C and excellent rate performance with retention capacity 105.2 mAh g-1 at 2 C have been achieved for Li/poly(VEC-r-LiSTFSI10)/LiFePO4 cells. The physical analysis and computation results indicate that the improved tLi+ with retaining high ionic conductivity can efficiently inhibit lithium dendrite growth and improve the electrochemical performance. Moreover, the assembled Li/poly(VEC-r-LiSTFSI10)/LiFePO4 soft pack can successfully continue to supply power even in the bent and cut state, which exhibits the superior safety for potential commercial application.

Design single-ion conducting polymer electrolyte towards practical solid-state batteries

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.