Linear ether electrolyte and asymmetric end groups for use in lithium batteries
View Patent ↗A primary electrochemical cell and electrolyte incorporating a linear asymmetric ether is disclosed. The ether may include EME, used in combination with DIOX and DME, or have the general structural formula R 1 —O—CH 2 —CH 2 —O—R 2 or R 1 —O—CH 2 —CH(CH 3 )—O—R 2 , where a total of at least 7 carbon atoms must be present in the compound, and R 1 and R 2 consist alkyl, cyclic, aromatic or halogenated groups but cannot be the same group (i.e., R 1 ≠R 2 ).
1. An electrochemical cell comprising:
an anode consisting essentially of lithium or a lithium alloy;
a cathode comprising FeS 2 ; and
an electrolyte consisting essentially of at least one solute dissolved in a solvent blend of at least 40 vol. % 1,3-dioxolane, at least 10 vol. % of one or more linear asymmetric ethers and
an optional amount of 1,2-dimethoxyethane;
wherein the linear asymmetric ethers have a structural formula R 1 —O—CH 2 —CH(CH 3 )—O—R 2 and wherein R 1 and R 2 are alkyl groups, the linear asymmetric ethers have 7 or more carbon atoms and R 1 ≠R 2 .
2. An electrochemical cell according to claim 1 , wherein the solute includes at least one selected from the group consisting of: lithium iodide, lithium trifluoromethanesulfonate, lithium bistrifluoromethylsulfonyl imide, lithium perchlorate and lithium hexafluoroarsenate.
3. An electrochemical cell comprising:
an anode consisting essentially of lithium or a lithium alloy;
a cathode comprising FeS 2 ; and
an electrolyte consisting essentially of at least one solute dissolved in a solvent blend of at least 40 vol. % 1,3-dioxolane, at least 10 vol. % of a linear asymmetric ether;
wherein the linear asymmetric ether has a structural formula R 1 —O—CH 2 —CH(CH 3 )—O—R 2 and wherein at least 10 vol. % of 1,2-dimethoxyethane is included in the solvent blend, R 1 is an ethyl group and R 2 is a methyl group.
4. An electrochemical cell according to claim 3 , wherein the solute includes at least one selected from the group consisting of: lithium iodide, lithium trifluoromethanesulfonate, lithium bistrifluoromethylsulfonyl imide, lithium perchlorate and lithium hexafluoroarsenate.