Negative electrode, lithium battery including the same and method of manufacturing lithium battery
A negative electrode includes a current collector; and a negative active material layer on at least a surface of the current collector. The negative active material layer includes a porous matrix including lithium titanium oxide particles and metal nanoparticles that are alloyable with lithium. An average particle diameter of the lithium titanium oxide particles is at least two times greater than an average particle diameter of the metal nanoparticles.
1. A negative electrode for a lithium battery, the negative electrode comprising:
a current collector; and
a negative active material layer on at least a surface of the current collector;
the negative active material layer including a porous matrix including lithium titanium oxide particles and metal nanoparticles that are alloyable with lithium, and
an average particle diameter of the lithium titanium oxide particles being at least two times greater than an average particle diameter of the metal nanoparticles.
2. The negative electrode as claimed in claim 1 , wherein the average particle diameter of the lithium titanium oxide particles is 5 to 50 times greater than the average particle diameter of the metal nanoparticles.
3. The negative electrode as claimed in claim 1 , wherein the metal nanoparticles are located among the lithium titanium oxide particles.
4. The negative electrode as claimed in claim 1 , wherein the average particle diameter of the lithium titanium oxide particles is in a range of about 100 nm to about 1 μm.
5. The negative electrode as claimed in claim 1 , wherein the lithium titanium oxide particles include a compound represented by Formula 1:
Li x+3 Ti y O 12 <Formula 1>
wherein 2.4≦x≦4.2, and 4.8<y≦6.6.
6. The negative electrode as claimed in claim 1 , wherein an amount of the lithium titanium oxide particles is 3 to 10 times greater than that of the metal nanoparticles by weight.
7. The negative electrode as claimed in claim 1 , wherein the average particle diameter of the metal nanoparticles is in a range of about 10 nm to about 500 nm.
8. The negative electrode as claimed in claim 1 , wherein the metal nanoparticles include one or more selected from Si, Sn, Al, Ge, Pb, Bi, Sb, and an alloy or oxide thereof.
9. The negative electrode as claimed in claim 1 , wherein the metal nanoparticles include Si or SiO x (0<x<2).
10. The negative electrode as claimed in claim 1 , wherein the metal nanoparticles include metal particles coated with a carbonaceous coating layer.
11. The negative electrode as claimed in claim 1 , wherein an amount of the metal nanoparticles is in a range of about 0.1 wt % to about 50 wt % based on the total weight of the negative active material layer.
12. The negative electrode as claimed in claim 1 , wherein the lithium titanium oxide particles do not deintercalate lithium ions during charging and discharging of a lithium battery.
13. The negative electrode as claimed in claim 1 , wherein the lithium titanium oxide particles have electric conductivity.
14. The negative electrode as claimed in claim 1 , wherein the negative active material layer further includes a conductive material.
15. A lithium battery comprising the negative electrode as claimed in claim 1 .
16. A method of manufacturing a lithium battery, the method comprising:
providing a lithium battery assembly including a positive electrode, a negative electrode, a separator disposed between the positive electrode and the negative electrode, and an electrolyte, wherein providing the lithium battery assembly includes:
preparing a negative active material composition including metal nanoparticles and lithium titanium oxide particles; and
coating a current collector with the negative active material composition to manufacture a negative electrode including a negative active material layer formed on the current collector; and
charging and discharging the lithium battery assembly, wherein discharging the lithium battery assembly is performed at 1.5 V or less.
17. The method as claimed in claim 16 , wherein the lithium titanium oxide particles of the negative active material composition include a compound represented by Formula 2:
Li x Ti y O 12 <Formula 2>
wherein 2.4≦x≦4.2, and 4.8<y≦6.6.
18. The method as claimed in claim 17 , wherein during discharging the lithium battery assembly, the lithium titanium oxide particles include a compound represented by Formula 1:
Li x+3 Ti y O 12 <Formula 1>
wherein 2.4≦x≦4.2, and 4.8<y≦6.6.
19. The method as claimed in claim 16 , wherein the lithium titanium oxide particles of the lithium battery subjected to the discharging of the lithium battery assembly do not deintercalate lithium ions.
20. A method of using a lithium battery, the method comprising discharging the lithium battery of claim 15 at a voltage of 1.5 V or less.