Granted Patent B2

US 9,023,204 · App. 13/510,676 · Granted May 5, 2015

Abstract

Claims (18)

1. A purification system for removing hydrogen fluoride and water from a non-aqueous electrolytic solution for a lithium ion secondary battery, comprising:

a purifier for removing hydrogen fluoride containing an adsorbent selected from carbonate hydrotalcites or calcined hydrotalcites; and

a purifier for removing water connected downstream from the purifier for removing hydrogen fluoride, the purifier for removing water containing a water adsorbent,

each purifier comprising a housing, an electrolytic solution inlet member, an electrolytic solution outlet member and mesh for preventing outflow of the adsorbent at the inlet and outlet of the housing,

wherein the non-aqueous electrolytic solution flows into the purifier for removing hydrogen fluoride via the electrolytic solution inlet member of the purifier for removing hydrogen fluoride, whereby the non-aqueous electrolytic solution is supplied to the adsorbent selected from carbonate hydrotalcites or calcined hydrotalcites; out of the purifier for removing hydrogen fluoride via the electrolytic solution outlet member of the purifier for removing hydrogen fluoride; into the purifier for removing water via the electrolytic solution inlet member of the purifier for removing water, whereby the non-aqueous electrolytic solution is supplied to the water adsorbent; and out of the purifier for removing water via the electrolytic solution outlet member of the purifier for removing water.

2. The purification system according to claim 1 , wherein the purifier for removing hydrogen fluoride reduces a concentration of hydrogen fluoride contained in a non-aqueous electrolytic solution for a lithium ion secondary battery to less than 10 ppmw.

3. The purification system according to claim 1 , wherein the purifier for removing hydrogen fluoride attains a removal rate of the hydrogen fluoride of 90% or more.

4. The purification system according to claim 1 , wherein the purifier for removing water reduces a concentration of water contained in a non-aqueous electrolytic solution for a lithium ion secondary battery to 10 ppmw or less.

5. The purification system according to claim 1 , wherein the adsorbent contained in the purifier for removing hydrogen fluoride is a carbonate hydrotalcite which has a formula, [M 2+ 1−x M 3+ x (OH) 2 ] x+ [(CO 3 ) X/2 .mH 2 O] x− (m≧0) where 0<x≦0.33, M 2+ are divalent Mg, Mn, Fe, Co, Ni, Cu and Zn metal ions, and M 3+ are trivalent Al, Fe, Cr, Co and In metal ions.

6. The purification system according to claim 1 , wherein the adsorbent contained in the purifier for removing hydrogen fluoride is a calcined hydrotalcite which has a formula M 2+ 1−x M 3+ x O 1+x/2 , where 0<x≦0.33, M 2+ are divalent Mg, Mn, Fe, Co, Ni, Cu and Zn metal ions, and M 3+ are trivalent Al, Fe, Cr, Co and In metal ions.

7. The purification system according to claim 1 , wherein the water adsorbent is synthetic zeolite or activated alumina.

8. A purification system for removing hydrogen fluoride and water from a non-aqueous electrolytic solution for a lithium ion secondary battery, comprising:

a preliminary purifier for removing water containing an adsorbent for trapping water;

a purifier for removing hydrogen fluoride connected downstream from the preliminary purifier, the purifier for removing hydrogen fluoride containing an adsorbent selected from carbonate hydrotalcites or calcined hydrotalcites; and

a purifier for removing water connected downstream from the purifier for removing hydrogen fluoride, the purifier for removing water containing a water adsorbent,

each purifier comprising a housing, an electrolytic solution inlet member, an electrolytic solution outlet member and mesh for preventing outflow of the adsorbent at the inlet and outlet of the housing,

wherein the non-aqueous electrolytic solution flows into the preliminary purifier via the electrolytic solution inlet member of the preliminary purifier, whereby the non-aqueous electrolytic solution is supplied to the adsorbent for trapping water; out of the preliminary purifier via the electrolytic solution outlet member of the preliminary purifier; into the purifier for removing hydrogen fluoride via the electrolytic solution inlet member of the purifier for removing hydrogen fluoride, whereby the non-aqueous electrolytic solution is supplied to the adsorbent selected from carbonate hydrotalcites or calcined hydrotalcites; out of the purifier for removing hydrogen fluoride via the electrolytic solution outlet member of the purifier for removing hydrogen fluoride; into the purifier for removing water via the electrolytic solution inlet member of the purifier for removing water, whereby the non-aqueous electrolytic solution is supplied to the water adsorbent; and out of the purifier for removing water via the electrolytic solution outlet member of the purifier for removing water.

9. The purification system according to claim 8 , wherein the preliminary purifier reduces a concentration of water contained in a non-aqeuous electrolytic solution for a lithium ion secondary battery to 100 ppmw or less.

Assignments (8)