Gel polymer electrolytes have attracted much attention as a kind of polymer electrolyte with high lithium ion conduction efficiency. However

the process of preparing gel polymer electrolytes still has some problems

such as difficult removal of catalyst and complicated process. In this work

the strategy of cationic polymerization of vinyl ether monomers induced by the potential Lewis acid in the ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF

4

) was used to explore a method of

in situ

construction of high performance gel polymer electrolytes inside the battery. The introduction of BMIMBF

4

has improved the conductivity and electrochemical stability of gel polymer electrolytes. The lithium symmetrical battery based on the gel polymer electrolyte can cycle for 500 h at the current density of 0.1 mA·cm

-2

. The full battery

in situ

assembled by the gel polymer electrolyte is charged and discharged at a rate of 1 C

and the capacity retention is 90% after 100 cycles; Even at a high rate of 10 C

the discharge specific capacity of the battery can still be maintained at 67.5 mAh·g

-1

. The self-catalyzed strategy provides a new idea for the facile fabrication of gel polymer electrolytes.