The present invention provides an excellent nonaqueous electrolytic solution capable of improving low-temperature and high-temperature cycle properties and load characteristics after high-temperature charging storage, an electrochemical element using it, a...

Described herein is a production method of sulfonated polyarylene that is safe and enables easy control of the amount and position of sulfonic groups introduced in the polymer. The sulfonated polyarylene is also disclosed. The invention further provides a ...