Lithium secondary battery
The present invention may improve the lifetime characteristics of a lithium secondary battery, and particularly, may provide a non-aqueous electrolyte solution or cathode including a phosphate-based compound which may exhibit stable and excellent lifetime characteristics at high temperature and high voltage regardless of the moisture content or the presence of a pressing process of the electrode.
1. A cathode slurry comprising:
a lithium transition metal oxide; and
a compound represented by Chemical Formula 1:
where Y 1 and Y 2 are each independently silicon (Si) or tin (Sn),
R 1 to R 6 are each independently hydrogen or a C 1 -C 10 alkyl group, and
A is
where Y 3 is Si or Sn,
R 7 to R 9 are each independently hydrogen or a C 1 -C 10 alkyl group, and
n is between 2 and 4.
2. The cathode slurry of claim 1 , wherein the compound represented by Chemical Formula 1 is any one selected from the group consisting of compounds of (1) to (3), or a mixture of two or more thereof:
wherein Me represents CH 3 .
3. The cathode slurry of claim 1 , further comprises a compound represented by Chemical Formula 2:
where R 10 to R 18 are each independently hydrogen or a C 1 -C 10 alkyl group.
4. The cathode slurry of claim 3 , wherein the compound represented by Chemical Formula 2 is tris(trimethylsilyl)phosphate (TMSPa).
5. The cathode slurry of claim 3 , wherein a mixing ratio of the compound represented by Chemical Formula 1 to the compound represented by Chemical Formula 2 is in a range of 1:0.1 to 1:2 as a weight ratio.
6. The cathode slurry of claim 1 , wherein the compound represented by Chemical Formula 1 is included in an amount of 0.01 wt % to 5 wt % based on a total weight of the lithium transition metal oxide.
7. The cathode slurry of claim 1 , wherein the lithium transition metal oxide is a compound represented by Chemical Formula 3:
Li[Li x Ni a Co b Mn c ]O 2 (−0.05 ≤x ≤+0.5,0 <a,b,c≤ 1, x+a+b+c= 1, and 0.4 <c< 1) <Chemical Formula 3>.
8. A cathode formed by using the cathode slurry of claim 1 .
9. A lithium secondary battery comprising the cathode of claim 8 .
10. The lithium secondary battery of claim 9 , wherein a charge voltage of the lithium secondary battery is in a range of 4.3 V to 5.0 V.
11. A cathode slurry comprising:
a lithium transition metal oxide; and
a compound selected from the group consisting of compounds of (4) to (6), or a mixture of two or more thereof:
wherein Me represents CH 3 .
12. A cathode formed by using the cathode slurry of claim 11 .
13. A lithium secondary battery comprising the cathode of claim 12 .