US Government As Represented by the Secretary of the Army

Michael S Ding

T Richard Jow

Kang Xu

Shengshui Zhang

A non-aqueous electrolyte solution for lithium or a lithium ion cell, which improves lithium ion cell capacity retention and enhances storage life thereof. The non-aqueous solution can be implemented in the context of an electrolyte system that includes a lithium salt dissolved in a solvent formed from a mixture of one or more cyclic esters, and/or one or more chain esters, and at least one lactam based solvent. Such a system is suited for use with electrochemical energy storage devices, which are based on non-aqueous electrolytes, such as high energy density batteries and/or high power electrochemical capacitors. Such an electrochemical storage devices is generally based on non-aqueous electrolytes that include lithium salt dissolved in a solvent system.

Solvent systems comprising a mixture of lactams and esters for non-aqueous electrolytes and non-aqueous electrolyte cells comprising the same

Non-aqueous electrolyte solutions capable of protecting lithium metal and lithium-inserted carbonaceous electrodes include an electrolyte salt, preferably LiPF, and a non-aqueous electrolyte solvent mixture comprising at least one of trialkyl phosphites, one or more cyclic or/and linear carbonates, and optionally other additives, such as, gelling agents, ionically conductive solid polymers, and other additives. The trialkyl phosphites have the following general formula:wherein the oxidation number of the phosphorus atom is III (three), R, R, and Rare the same or different, independently selected from linear or branched alkyl groups having 1 to 4 carbon atoms, optionally but not limited to, with one or more of the alkyl substituents being substituted by one or more halogen atoms, preferably fluorine atoms.

Non-aqueous electrolyte solutions and non-aqueous electrolyte cells comprising the same

A non-aqueous electrolyte to be used in a Li-ion battery includes a lithium salt, a cyclic carbonate, a linear carbonate and an alkyl fluorinated phosphate, of the following general formulawherein R, Rand R, independently, are selected from the group consisting of straight and branched alkyl groups having 1-5 carbon atoms, and at least one of said alkyl groups is fluorinated, with the locations of said fluorination being at least &#x3b2;-positioned away from the phosphorous of said phosphate, such that said alkyl phosphate has a F/H ratio of at least 0.25, and said electrolyte solution is non-flammable.

Nonflammable non-aqueous electrolyte and non-aqueous electrolyte cells comprising the same

A non-aqueous electrolyte to be used in a Li-ion battery includes a lithium salt, a cyclic carbonate, a linear carbonate and an isocyanate-based additive, with the following general formulaR&#x2014;N&#x2550;C&#x2550;Owherein Rrepresents linear or branched alkyl groups which have 1 to 7 carbon atoms, or aromatic groups having the following general formulawherein Rand R, which may be the same or different and located at any positions of carbons 2, 2', 3, 3&#x2032; and 4 in the benzyl ring, represent hydrogen atoms or halogen atoms, isocyanate groups, either groups, ester groups or alkyl groups, having 1 to 3 carbon atoms, and are optionally substituted with halogen atoms.

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Gaithersburg, MD, United States of America

Michael S Ding