Electrolytes with ionic liquid additives for lithium ion batteries
First Claim
1. An electrolyte for a lithium ion battery having an anode made of anode material particles and a cathode, said electrolyte consisting of carbonate containing electrolyte, at least one lithium salt and an additive present in an amount up to 10 volume percent of the electrolyte, the additive consisting of at least one ionic liquid which consists of cations and anions, wherein, while operating the battery:
- during charging of the battery, at least the cations form, upon application of an electric field in a vicinity of the anode, a mobile layer at surfaces of the anode material particles, which accommodates expansion of the anode material particles by rearrangement of at least the cations,during discharging of the battery, at least the cations diffuse into the carbonate-containing electrolyte; and
wherein the anions comprise at least one sulfonylimide, substituted or unsubstituted, and the cations comprise at least one piperidinium, substituted or unsubstituted, wherein the at least one ionic liquid is further selected to have a melting temperature below 10°
C.
1 Assignment
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Accused Products
Abstract
Electrolytes, anodes, lithium ion cells and methods are provided for preventing lithium metallization in lithium ion batteries to enhance their safety. Electrolytes comprise up to 20% ionic liquid additives which form a mobile solid electrolyte interface during charging of the cell and prevent lithium metallization and electrolyte decomposition on the anode while maintaining the lithium ion mobility at a level which enables fast charging of the batteries. Anodes are typically metalloid-based, for example include silicon, germanium, tin and/or aluminum. A surface layer on the anode bonds, at least some of the ionic liquid additive to form an immobilized layer that provides further protection at the interface between the anode and the electrolyte, prevents metallization of lithium on the former and decomposition of the latter.
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Citations
21 Claims
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1. An electrolyte for a lithium ion battery having an anode made of anode material particles and a cathode, said electrolyte consisting of carbonate containing electrolyte, at least one lithium salt and an additive present in an amount up to 10 volume percent of the electrolyte, the additive consisting of at least one ionic liquid which consists of cations and anions, wherein, while operating the battery:
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during charging of the battery, at least the cations form, upon application of an electric field in a vicinity of the anode, a mobile layer at surfaces of the anode material particles, which accommodates expansion of the anode material particles by rearrangement of at least the cations, during discharging of the battery, at least the cations diffuse into the carbonate-containing electrolyte; and wherein the anions comprise at least one sulfonylimide, substituted or unsubstituted, and the cations comprise at least one piperidinium, substituted or unsubstituted, wherein the at least one ionic liquid is further selected to have a melting temperature below 10°
C. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 21)
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- 17. An electrolyte for a lithium ion battery having an anode made of anode material particles and a cathode, said electrolyte consisting of carbonate containing electrolyte, at least one lithium salt and an additive present in an amount up to 10 volume percent of the electrolyte, the additive consisting of at least one ionic liquid which consists of cations and anions, wherein the at least one ionic liquid consists of at least one sulfonylimide, substituted or unsubstituted, and at least one piperidinium, substituted or unsubstituted, selected to have a melting temperature below 10°
Specification