Non-aqueous liquid electrolyte and non-aqueous liquid electrolyte secondary battery

Abstract

A non-aqueous liquid electrolyte secondary battery using negative-electrode active material having Si, Sn and/or Pb, with high charge-capacity, superior characteristics including discharge-capacity retention rate over long is provided. Its non-aqueous liquid electrolyte contains carbonate having unsaturated bond and/or halogen and compounds like LiPF₆ and/or LiBF₄ (first lithium salt) and lithium salt different from said first one, represented by formula below (second lithium salt).

Li_l(α_mX^a_n)

Description

TECHNICAL FIELD [0001]The present invention relates to a non-aqueous liquid electrolyte and non-aqueous liquid electrolyte secondary battery using the same. Particularly, it relates to a non-aqueous liquid electrolyte, which shows superior charge-discharge cycle performance when used for a non-aqueous liquid electrolyte secondary battery utilizing a negative-electrode active material having at least one kind of atom selected from the group consisting of Si atom, Sn atom and Pb atom, and also relates to a non-aqueous liquid electrolyte secondary battery using the non-aqueous liquid electrolyte.BACKGROUND ART [0002]In recent years, with the reduction in weight and size of electrical appliances, development of a non-aqueous liquid electrolyte secondary battery having high energy density, for example lithium secondary battery, has been advanced. Also, as application field of lithium secondary battery is expanded, further improvement in its battery characteristics has been desired.[0003]...

AI Technical Summary

Benefits of technology

[0036]Further, it is preferable that, in the above formula (A-1), α is carbon atom, nitrogen atom or oxygen atom, and Xa is a group represented by —SO2Ra0 (in this context, Ra0 represents fluorine atom or a hydrocarbon group. When Ra0 is a hydrocarbon group, a part or all of the hydrogen atoms may be substituted with a fluorine atom. In addition, when the number of Xa is two or more, the two or more of Ra0 may be the same or different from each other and further, the two or more of Ra0...

Problems solved by technology

Although higher capacity was thereby obtained, they were inadequate with respect to perfo...

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