Cathode active material for overcharge protection in secondary lithium batteries
View Patent ↗Provided herein is an electrode active material comprising a lithium metal oxide and an overcharge protection additive having an operating voltage higher than the operating voltage of the lithium metal oxide.
1. A positive electrode comprising a physical mixture of a first electrode active material and a second electrode active material coated onto a collector of the positive electrode; and
wherein the first electrode active material comprises a lithium metal oxide, and wherein the second electrode active material comprises an overcharge protection additive having an operating voltage higher than the operating voltage of the lithium metal oxide, wherein the overcharge protection additive is a Li-rich layered oxide, a lithium oxide spinel, an olivine phosphate, and combinations thereof.
2. A positive electrode comprising a physical mixture of a first electrode active material and a second electrode active material coated onto a collector of the positive electrode; and
wherein the first electrode active material comprises a lithium metal oxide, and wherein the second electrode active material comprises an overcharge protection additive having an operating voltage higher than the operating voltage of the lithium metal oxide, wherein the overcharge protection additive has the formula xLi 2 M 1 O 3 (1−x)LiM 2 O 2 , wherein: M 1 is Mn, Ti, Zr, and combinations thereof; M 2 is Mn, Ni, Co, Cr, or combinations thereof, and x is greater than 0 and smaller than 1.
3. A lithium ion battery comprising a positive electrode comprising a positive electrode active material mixture, a negative electrode comprising a negative electrode active material, and an electrolyte, the positive electrode active material mixture comprises a physical mixture of a first electrode active material and a second electrode active material, wherein the first electrode active material comprises a lithium metal oxide, and wherein the second electrode active material comprises an overcharge protection additive having an operating voltage higher than an operating voltage of the lithium metal oxide, wherein the overcharge protection additive is a Li-rich layered oxide, a lithium oxide spinel, an olivine phosphate, and combinations thereof.