Electrolyte compositions comprising ionic liquids and metal hydride batteries comprising same

Patent metadata

Field	Value
Publication number	US-10587012-B2
Application number	US-201514669588-A
Country	US
Kind code	B2
Filing date	Mar 26, 2015
Priority date	Mar 26, 2015
Publication date	Mar 10, 2020
Grant date	Mar 10, 2020

Abstract

Electrolyte compositions comprising a) an ionic liquid and b) a protic acid and/or an organic solvent are suitable for use in electrochemical cells, e.g. metal hydride batteries. The electrolyte compositions may replace the currently employed 30% by weight aqueous KOH. Suitable protic acids include carboxylic acids, mineral acids, sulfonic acids and the like. Suitable organic solvents include organic carbonates, ethers, glymes, ortho esters, polyalkylene glycols, esters, lactones, glycols, formates, sulfones, sulfoxides, amides, alcohols, ketones, nitro solvents, nitrile solvents and combinations thereof. Present batteries may achieve a nominal open-circuit voltage of >1.2 V (volts) and up to about 6 V. The electrolyte compositions allow enlargement of the electrochemical window, thus allowing the use of further cathode active materials. Further cathode active materials include transition metals and their oxides, hydroxides and fluorides; for example, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, Lu, Hf, Ta, W, Re, Os, Ir, Pt and Au and their oxides, hydroxides, oxide/hydroxides and fluorides.

First claim

The invention claimed is:

1. A metal hydride secondary battery comprising at least one negative electrode, at least one positive electrode, a casing having said electrodes positioned therein and an electrolyte composition, wherein:
the negative electrode comprises ABx metal alloy capable of reversibly adsorbing and desorbing hydrogen; and
the electrolyte composition comprises
a) an ionic liquid and
b) a protic acid selected from the group consisting of boric acid, hydrofluoric acid, hydrobromic acid, hydroiodic acid, perchloric acid, periodic acid; sodium bisulfate, potassium bisulfate, HAsF 6 , HBF 4 , H(OEt 2 )BF 4 , and HPF 6 , or
the protic acid selected from the group consisting of sulfonic acids of formula RSO 3 H wherein R is alkyl or aryl or alkyl or aryl substituted by one to three halogens; [H(OEt 2 ) 2 ][B[3,5-(CF 3 ) 2 C 6 H 3 ] 4 ], [H(OEt 2 ) 2 ][B(C 6 F 5 ) 4 ] and [H(OEt 2 ) 2 ][Al(OC(CF 3 ) 3 ) 4 ].

2. A battery according to claim 1 , wherein the electrolyte composition comprises a protic acid wherein the weight/weight ratio of the ionic liquids in total to the protic acids in total is from about 99.5/0.5 to about 0.5/99.5.

3. A battery according to claim 1 , wherein the electrolyte composition comprises an organic solvent wherein the weight/weight ratio of the ionic liquids in total to the organic solvents in total is from about 99.5/0.5 to about 0.5/99.5.

4. A battery according to claim 1 , wherein the electrolyte composition comprises an ionic liquid, a protic acid and an organic solvent.

5. A battery according to claim 1 , wherein the ionic liquid contains a cation selected from the group consisting of formulae (a)-(h)

wherein
each R is independently H, C 1 -C 16 alkyl or hydroxyC 1 -C 16 alkyl, for instance methyl, ethyl, hydroxyethyl or propyl and
X is CH 2 , O, S or NR wherein R is H or C 1 -C 16 alkyl, for instance H, methyl, ethyl or propyl.

6. A battery according to claim 1 , wherein the ionic liquid contains an anion selected from the group consisting of carboxylates, imides, methides, nitrate, bifluoride, halides, borates, phosphates, phosphinates, phosphonates, sulfonates, sulfates, carbonates and aluminates.

7. A battery according to claim 1 , wherein the ionic liquid contains an anion selected from the group consisting of F 2 P(C 2 F 5 ) 4 − , F 3 P(C 2 F 5 ) 3 − , F 4 P(C 2 F 5 ) 2 − , F 2 P(C 3 F 7 ) 4 − , F 3 P(C 3 F 7 ) 3 − , F 4 P(C 3 F 7 ) 2 − , F 2 P(C 4 F 9 ) 4 − , F 3 P(C 4 F 9 ) 3 − , F 4 P(C 4 F 9 ) 2 − , perfluoroalkylcarboxylate, perfluoroalkylsulfonate, bis(perfluoroalkylsulfonyl)imide, (perfluoroalkylsulfonyl)(perfluoroalkylcarboxyl)imide, tris(perfluoroalkylsulfonyl)methide, trifluoroacetate, trifluoromethanesulfonate (triflate), bis(trifluoromethylsulfonyl)imide, tris(trifluoromethylsulfonyl)methide, tetrafluoroborate, spiro-oxo borates and spiro-oxo phosphates.

8. A battery according to claim 1 , wherein the ionic liquid contains a carboxylate anion of formula RCOO − wherein R is hydrogen or hydrocarbyl.

9. A battery according to claim 1 , wherein the ionic liquid contains an anion selected from the group consisting of dicyanamide, N(SO 2 F) 2 − , a bis(perfluoroalkylsulfonyl)imide, bis(pentafluoroethylsulfonyl)imide, N(CF 3 SO 2 )(CF 3 (CF 2 ) 3 SO 2 ) − , a (perfluoroalkylsulfonyl)(perfluoroalkylcarboxyl)imide; a tris(perfluoroalkylsulfonyl)methide; bifluoride; chloride, bromide, iodide, fluoride; orthoborate, tetrahydroxyborate, tetraborate, tetraphenylborate, [B(3,5-(CF 3 ) 2 C 6 H 3 ) 4 ] − , B(C 2 O 4 ) 2 − (bis(oxalato)borate), difluoro(oxalato)borate, di(trifluoroacetato)oxalatoborate, B(C 6 F 5 ) 4 − , BF 4 − ; dihydrogen phosphate, hydrogen phosphate, alkyl phosphate, dialkyl phosphate, phosphate, PF 6 − , HPO 3 F − , trisoxalatophosphate, tetrafluorooxalatophosphate, a fluoro(perfluoroalkyl)phosphate; an alkylsulfonate, an arylsulfonate, a perfluoroalkylsulfonate; hydrogensulfate, sulfate, thiosulfate, an alkylsulfate; carbonate, hydrogencarbonate, an alkylcarbonate; Al(OC(CF 3 ) 3 ) 4 − , di(trifluoroacetato)oxalatoaluminate, tetrachloroaluminate, tetrafluoroaluminate, tetraiodoaluminate and tetrabromoaluminate.

10. A battery according to claim 1 , wherein the ionic liquid is selected from the group consisting of diethylmethylammonium trifluoromethanesulfonate, ethylammonium nitrate, triethylammonium methanesulfonate, 2-methylpyridinium trifluoromethanesulfonate, ammonium fluoride, methylammonium nitrate, hydroxyethylammonium nitrate, ethylammonium nitrate, dimethylammonium nitrate, 1-methylimidazolium nitrate, 1-ethylimidazolium nitrate, t-butylammonium tetrafluoroborate, hydroxyethylammonium tetrafluoroborate, methylbutylammonium tetrafluoroborate, triethylammonium tetrafluoroborate, imidazolium tetrafluoroborate, 1-methylimidazolium tetrafluoroborate, 1,2-dimethylimidazolium tetrafluoroborate, t-butylammonium triflate, 2-fluoropyridinium triflate, hydroxyethylammonium triflate, 1,2-dimethylimidazolium triflate, imidazolium triflate, 1-methylimidazolium hydrogensulfate, 1-methylimidazolium chloride, 1-methylimidazolium triflate, hydronium triflate, methylammonium mesylate, ethylammonium mesylate, butylammonium mesylate, methoxyethylammonium mesylate, dimethylammonium mesylate, dibutylammonium mesylate, triethylammonium mesylate, dimethylethylammonium mesylate, hydronium hydrogensulfate, ammonium hydrogensulfate, methylammonium hydrogensulfate, ethylammonium hydrogensulfate, propylammonium hydrogensulfate, n-butylammonium hydrogensulfate, t-butylammonium hydrogensulfate, dimethylammonium hydrogensulfate, diethylammonium hydrogensulfate, di-n-butylammonium hydrogensulfate, methylbutylammonium hydrogensulfate, ethylbutylammonium hydrogensulfate, trimethylammonium hydrogensulfate, triethylammonium hydrogensulfate, tributylammonium hydrogensulfate, dimethylethylammonium hydrogensulfate, dibutylammonium fluorohydrogen phosphate, triethylammonium fluorohydrogen phosphate, tributylammonium fluorohydrogen phosphate, hydronium dihydrogen phosphate, methylammonium dihydrogen phosphate, ethylammonium dihydrogen phosphate, propylammonium dihydrogen phosphate, n-butylammonum dihydrogen phosphate, methoxyethylammonium dihydrogen phosphate, dimethylammonium dihydrogen phosphate, dibutylammonium dihydrogen phosphate, methylbutylammonium dihydrogen phosphate, ammonium bifluoride, methylammonium bifluoride, ethylammonium bifluoride, dimethylammonium bifluoride, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate, 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-ethyl-3-methylimidazolium acetate, 1-butyl-3-methylimidazolium trifluoromethanesulfonate, 1-butyl-3-methylimidazolium acetate, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, tri-n-butylmethylammonium methylsulfate, 1-ethyl-2,3-dimethylimidazolium ethylsulfate, 1-butyl-3-methylimidazolium thiocyanate, 1-butyl-3-methylimidazolium tetrachloroaluminate, 1-butyl-3-methylimidazolium methylsulfate, 1-butyl-3-methylimidazolium methanesulfonate, 1-butyl-3-methylimidazolium hydrogencarbonate, 1-butyl-3-methylimidazolium hydrogensulfate, 1-butyl-3-methylimidazolium chloride, 1,2,3-trimethylimidazolium methylsulfate, tris-(hydroxyethyl)methylammonium methylsulfate, 1,2,4-trimethylpyrazolium methylsulfate, 1,3-dimethylimdiazolium hydrogencarbonate, 1-ethyl-3-methylimidazolium hydrogencarbonate, 1-ethyl-3-methylimidazolium chloride, 1-ethyl-3-methylimidazolium tetrachloroaluminate, 1-ethyl-3-methylimidazolium thiocyanate, 1-ethyl-3-methylimidazolium methanesulfonate, 1-ethyl-3-methylimidazolium hydrogensulfate

Assignees

• Basf Corp

Inventors

• Meng Tiejun
• Young Kwo
• Wong Diana
• Nei Jean

Classifications

• H01M2300/0037

  Mixture of solvents · CPC title

• H01M2300/0045

  Room temperature molten salts comprising at least one organic ion · CPC title

• H01M10/345 Primary

  Gastight metal hydride accumulators · CPC title

• H01M2300/0005

  Acid electrolytes · CPC title

• H01M2300/004

  Three solvents · CPC title