Electrode active material with low moisture retention and lithium secondary battery including the same
View Patent ↗The present invention is directed to a lithium secondary battery comprising an anode comprising an anode active material, a cathode comprising a cathode active material, and a polymer membrane, wherein the polymer membrane is disposed between the cathode and the anode, wherein the anode active material comprises a mixture of at least two kinds of lithium metal oxide particles having different mass median particle diameters D50, wherein the lithium metal oxide particles are secondary particles comprising primary particles, the mixture comprises first lithium metal oxide particles having a mass median particle diameter D50 of 1 nm to less than 3 μm, second lithium metal oxide particles having a mass median particle diameter D50 of 3 μm to 30 μm, and a mix ratio of the first lithium metal oxide particles to the second lithium metal oxide particles is 70:30 to 30:70.
1. A lithium secondary battery comprising:
an anode comprising an anode active material,
a cathode comprising a cathode active material, and
a polymer membrane, wherein the polymer membrane is disposed between the cathode and the anode,
wherein the anode active material comprises a mixture of at least two kinds of lithium metal oxide particles having different mass median particle diameters D50,
wherein the lithium metal oxide particles are—consist of secondary particles comprising primary particles,
the mixture comprises the first lithium metal oxide particles having a mass median particle diameter D50 of 700 nm to less than 1.8 μm and second lithium metal oxide particles having a mass median particle diameter D50 of 12 μm to less than 20 μm, and
a mix ratio of the first lithium metal oxide particles to the second lithium metal oxide particles is 70:30 to 30:70,
wherein the lithium metal oxide particles of the anode active material is composed of a lithium metal oxide represented by Formula 2 below:
Li a Ti b O 4 (2)
wherein 0.5≤a≤3 and 1≤b≤2.5, and
the cathode active material is composed of a lithium metal oxide represented by Formula 3 below:
Li x M y Mn 2−y O 4−z ,A z (3)
wherein 0.9<x<1.2, 0<y<2, and 0<z<0.2;
M is at least one element selected from the group consisting of Al, Mg, Ni, Co, Fe, Cr, V, Ti, Cu, B, Ca, Zn, Zr, Nb, Mo, Sr, Sb, W, Ti, and Bi; and
A is at least one monovalent or divalent anion.
2. The lithium secondary battery according to claim 1 , wherein the lithium metal oxide represented by Formula 2 is Li 1.33 Ti 1.67 O 4 or LiTi 2 O 4 .
3. The lithium secondary battery according to claim 1 , wherein the lithium secondary battery is a lithium ion battery.
4. The lithium secondary battery according to claim 1 , wherein the lithium secondary battery is a lithium ion polymer battery.
5. The lithium secondary battery according to claim 1 , wherein the lithium secondary battery is a lithium polymer battery.