Additives for overcharge protection in non-aqueous rechargeable lithium batteries
AssigneeE-One Moli Energy (Canada) Limited
InventorsJan Naess Reimers, Brian Michael Way
Life of this patent
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Abstract
Non-aqueous rechargeable lithium batteries can be protected against overcharge abuse by incorporating small amounts of suitable additives into the electrolyte. Additives selected from the group consisting of phenyl-R-phenyl compounds wherein R is an aliphatic hydrocarbon, fluorine substituted biphenyl compounds, and 3-thiopheneacetonitrile can provide superior cycling performance along with satisfactory overcharge protection in high voltage lithium ion batteries. 2,2-diphenylpropane can be a preferred gassing agent additive in batteries equipped with electrical disconnect devices.
Claims26
A non-aqueous rechargeable lithium battery having a lithium insertion compound cathode, a lithium or lithium compound anode, a non-aqueous electrolyte, a maximum operating charging voltage, and an additive mixed in said electrolyte, said additive polymerizing at battery voltages greater than the maximum operating charging voltage thereby protecting the battery during or after overcharge abuse, wherein the additive is selected from the group consisting of:
- i) phenyl-R-phenyl compounds wherein R is an aliphatic hydrocarbon,
- ii) fluorine substituted biphenyl compounds, and
- iii) 3-thiopheneacetonitrile.
A method for providing overcharge protection in a non-aqueous rechargeable lithium battery, the battery having a lithium insertion compound cathode;
- a lithium or lithium compound anode;
- a non-aqueous electrolyte;
- a maximum operating charging voltage;
- and an additive mixed in said electrolyte;
- said additive irreversibly polymerizing at battery voltages greater than the maximum operating charging voltage such that the battery is protected during or after overcharge abuse, which comprises:
- a) selecting an additive from the group consisting of phenyl-R-piheniyl compounds wherein R is an aliphatic hydrocarbon, fluorine substituted biphenyl compounds, and 3-thiopheneacetonitrile;
- and
- b) mixing an amount of the additive in said electrolyte wherein the amount is sufficient to protect the battery as the additive reacts during overcharge abuse.
Dependencies are inferred from the claim text.