Abstract: A lithium secondary battery includes a positive electrode, a negative electrode, a separator disposed between the positive electrode and the negative electrode, and a non-aqueous electrolyte, wherein in the negative electrode, lithium metal deposits during charging and the lithium metal dissolves during discharging, the non-aqueous electrolyte includes a fluoroalcohol, an oxalate complex anion including fluorine, a lithium ion, and a non-aqueous solvent.

Abstract: A lithium secondary battery includes a positive electrode, a negative electrode, a separator interposed between the positive electrode and the negative electrode, and a non-aqueous electrolyte, wherein the non-aqueous electrolyte includes a fluorinated vinylene ether compound A having a —CF?CH—O— bond, and a non-aqueous solvent.

Abstract: A lithium secondary battery includes a positive electrode, a negative electrode, a separator disposed between the positive electrode and the negative electrode, and a non-aqueous electrolyte. The positive electrode includes a lithium-transition metal composite oxide. The lithium-transition metal composite oxide contains at least Ni, and has a ratio of Ni to total metal elements other than Li of 90 mol% or more. In the negative electrode, lithium metal deposits during charge, and the lithium metal dissolves during discharge. The non-aqueous electrolyte includes a non-aqueous solvent, lithium ions, an oxalate complex anion having fluorine, and nitrate anions.

Abstract: A lithium secondary battery includes a positive electrode, a negative electrode, a separator disposed between the positive electrode and the negative electrode, and a nonaqueous electrolyte. In the negative electrode, lithium metal deposits during charging and the lithium metal dissolves during discharging. The nonaqueous electrolyte includes a lithium ion, a cation of a metal M1 that forms an alloy with lithium, and a halide ion.

Abstract: A non-aqueous electrolyte secondary battery including a positive electrode, a separator, a negative electrode facing the positive electrode, with the separator interposed; and a liquid electrolyte. The positive electrode includes a composite oxide containing lithium as a first metal, and a second metal other than lithium. In the composite oxide, the second metal contains Ni, a content of Ni in the second metal is 90 at % or more, and a content of Co in the second metal is 10 at % or less. The liquid electrolyte contains at least one cation X selected from the group consisting of Na+, K+, Rb+, Cs+, Fe, Mg2+, Ca2+, Sr2+, Ba2+, and Al3+, and an oxalate complex anion Y.

Abstract: A lithium secondary battery including a positive electrode, a negative electrode, a lithium ion conductive nonaqueous electrolyte, and a separator disposed between the positive electrode and the negative electrode; on the negative electrode, a lithium metal deposits at the time of charging, the lithium metal dissolves in the nonaqueous electrolyte at the time of discharging; the nonaqueous electrolyte contains a cation and an anion; the cation includes a lithium ion, and at least one cation X selected from the group consisting of Na, K, Rb, Cs, Fr, Mg, Ca, Sr, Ba, and Al; and the anion includes an oxalate complex anion Y.