Patent ID: 9356319
Filing Date: 2016-05-31
CPC Classification: C01B,H01M,Y02E,Y02P

Claim Text:
1. A production method of a lithium tetrafluoroborate solution for use as a lithium battery electrolytic solution, comprising the steps of: (a) reacting lithium fluoride and boron trifluoride in a chain carbonate ester solvent, thereby obtaining a reaction solution of the lithium tetrafluoroborate dissolved in the chain carbonate ester solvent; (b) adding to the reaction solution at least one compound selected from the group consisting of lithium hexafluorophosphate, lithium hexafluoroarsenate, or lithium hexafluoroantimonate, thereby reacting water present in the reaction solution and generating an acidic impurity component; (c) removing the acidic impurity-component from the reaction solution by concentrating the reaction solution after step (b); and (d) diluting the concentrated solution after step (c), wherein the lithium tetrafluoroborate solution has an acidic impurity content of 50 mass ppm or lower and a water content of 15 mass ppm or lower.