Aprotic solvent electrolytes and batteries using same

Claim 2

An electrochemical cell comprised of: positive and negative electrodes with said negative electrode comprising lithium; and an electrolyte providing an ionically conductive path between said electrodes comprised of an ionically dissociable lithium salt and a solvent for said salt consisting of a compound from the class consisting of 2-methyltetrahydrofuran, 2,5-dimethyltetrahydrofuran, 2-methyltetrahydropyran, 2,6-dimethyltetrahydropyran, and higher alkyl homologs thereof.

Claim 3

A rechargeable electrochemical cell comprising: positive and negative electrodes with said negative electrode consisting essentially of lithium as the active electrode materal; and an electrolyte providing an ionically conductive path between said electrodes, said electrolyte comprising an ionically dissociable lithium salt and a solvent for said salt which is primarily one or more compounds represented by the formula ##STR2## where R 1 and R 2 are both alkyl groups or one of them is an alkyl group and the other is hydrogen, said alkyl group being a methyl, ethyl, propyl, isopropyl, butyl, isobutyl or tertiary butyl group.

Claim 4

A rechargeable electrochemical cell comprising: positive and negative electrodes with said negative electrode consisting essentially of lithium as the active electrode materal; and an electrolyte providing an ionically conductive path between said electrodes, said electrolyte comprising an ionically dissociable lithium salt and a solvent for said salt which is primarily one or more compounds represented by the formula ##STR2## where R 1 and R 2 are both alkyl groups or one of them is an alkyl group and the other is hydrogen, said alkyl group being a methyl, ethyl, propyl, isopropyl, butyl, isobutyl or tertiary butyl group.

Claim 5

A cell according to claim 2 where the solvent comprises 2-methyltetrahydrofuran.

Claim 6

A cell according to claim 3 wherein the solvent consists of 2-methyltetrahydrofuran.

Claim 7

A cell according to claim 4 wherein the solvent consists of 2,5-dimethyltetrahydrofuran.

Claim 8

A cell according to claim 2 where the solvent comprises 2,5-dimethyltetrahydrofuran.

Claim 9

A rechargeable cell according to claim 2 in which the positive electrode is titanium disulfide or a lithium polysulfide.

Claim 10

A cell according to claim 2 wherein the solute is a lithium salt other than lithium perchlorate.

Claim 11

An electrolyte for use in an electrochemical cell having a lithium negative electrode, said electrolyte comprising an ionically dissociable solute in the form of a lithium salt and a solvent for said salt which comprises predominantly one or more members from the class consisting of compounds conforming to the formula ##STR3## where R 1 and R 2 are both alkyl groups or one of them is an alkyl group and the other is hydrogen, said alkyl group being a methyl, ethyl, propyl, isopropyl, butyl, isobutyl or tertiary butyl group.

Claim 12

An electrolyte for use in an electrochemical cell having a lithium negative electrode, said electrolyte comprising an ionically dissociable solute in the form of a lithium salt and a solvent for said salt which comprises predominantly one or more members from the class consisting of compounds conforming to the formula ##STR3## where R 1 and R 2 are both alkyl groups or one of them is an alkyl group and the other is hydrogen, said alkyl group being a methyl, ethyl, propyl, isopropyl, butyl, isobutyl or tertiary butyl group.

Claim 13

An electrolyte according to claim 9 where the solvent comprises 2-methyltetrahydrofuran.

Claim 14

An electrolyte according to claim 9 where the solvent comprises 2,5-dimethyltetrahydrofuran.

Claim 15

An electrolyte according to claim 9 where the solvent comprises only one cyclic ether, and that one cyclic ether is either 2 methyltetrahydrofuran or 2,5-dimethyltetrahydrofuran.

Claim 16

An electrolyte according to claim 12 where the solute consists of or comprises lithium perchlorate.

Claim 17

An electrolyte according to claim 12 where the solute consists of or comprises lithium hexafluoroarsenate.

Claim 18

An electrolyte according to claim 6 where the solute consists of or comprises one of the following: lithium hexafluorophosphate, lithium perchlorate, lithium hexafluoroarsenate, lithium tetrachloroaluminate, lithium bromide, lithium tetrafluoroborate, lithium tetrabromoaluminate, lithium thiocyanate, and lithium salts of trichloroacetic, trifluoroacetic, trifluoromethanesulfonic, and formic acids.

Claim 19

An electrolyte according to claim 15 wherein the solvent includes at least one of the following compounds: tetrahydrofuran, tetrahydropyran, 1,2-dimethyloxyethane and diethylether.

Claim 20

An electrolyte according to claim 16 wherein the solvent comprises 2-methyltetrahydrofuran and at least one of the following: tetrahydrofuran, 1,2-dimethyloxyethane, diethylether and tetrahydropyran.

Claim 21

An electrolyte according to claim 16 wherein the solvent comprises 2,5-dimethyltetrahydrofuran and at least one of the following: tetrahydrofuran, 1,2-dimethyloxyethane, diethylether and tetrahydropyran.

Claim 22

An electrolyte according to claim 9 wherein the solute consists of or comprises one of the following: lithium hexafluorophosphate, lithium hexafluoroarsenate, lithium tetrachloroaluminate, lithium bromide, lithium tetrafluoroborate, lithium tetrabromoaluminate, lithium thiocyanate, and lithium salts of trichloroacetic, trifluoroacetic, trifluoromethanesulfonic, and formic acids.

Claim 23

An electrolyte according to claim 19 wherein the solvent consists of either or both members of the group consisting of 2-methyltetrahydrofuran and 2,5-dimethyltetrahydrofuran.