Protected anode and lithium air battery and all-solid battery including protected anode
A protected anode including an anode including a lithium titanium oxide; and a protective layer including a compound represented by Formula 1 below, a lithium air battery including the same, and an all-solid battery including the protected anode: Li 1+X M X A 2−X Si Y P 3−Y O 12 <Formula 1> wherein M may be at least one of aluminum (Al), iron (Fe), indium (In), scandium (Sc), or chromium (Cr), A may be at least one of germanium (Ge), tin (Sn), hafnium (Hf), and zirconium (Zr), 0≦X≦1, and 0≦Y≦1.
1. A protected anode comprising an anode comprising:
a lithium titanium oxide represented by Formula 3 below as an anode active material; and
a protective layer formed on the surface of the anode and comprising
a compound represented by Formula 2 below:
Li 1+X Al X Ge 2−X (PO 4 ) 3 <Formula 2>
wherein 0.3≦X≦0.7, and
Li 4+a Ti 5−b M′ c O 12−d <Formula 3>
wherein −0.2≦a≦0.2, −0.3≦b≦0.3, 0≦c≦0.3, −0.3≦d≦0.3, and
M′ is at least one of a Group 1 element to a Group 6 element or a Group 8 element to a Group 15 element.
2. The protected anode of claim 1 , wherein the compound of Formula 1 is one of Li 1.3 Al 0.3 Ge 1.7 (PO 4 ) 3 , Li 1.4 Al 0.4 Ge 1.6 (PO 4 ) 3 , Li 1.5 Al 0.5 Ge 1.5 (PO 4 ) 3 , Li 1.6 Al 0.6 Ge 1.4 (PO 4 ) 3 , and Li 1.7 Al 0.7 Ge 1.3 (PO 4 ) 3 .
3. The protected anode of claim 1 , wherein the lithium titanium oxide comprises Li 4 Ti 5 O 12 or Li 7 Ti 5 O 12 .
4. The protected anode of claim 1 , wherein the lithium titanium oxide comprises Li 4 Ti 5 O 12 or Li 7 Ti 5 O 12 , and the compound of Formula 1 comprises Li 1.3 Al 0.3 Ge 1.7 (PO 4 ) 3 , Li 1.4 Al 0.4 Ge 1.6 (PO 4 ) 3 , Li 1.5 Al 0.5 Ge 1.5 (PO 4 ) 3 , Li 1.6 Al 0.6 Ge 1.4 (PO 4 ) 3 , or Li 1.7 Al 0.7 Ge 1.3 (PO 4 ) 3 .
5. The protected anode of claim 1 , further comprising, between the anode and the protective layer, at least one interlayer of a separator, a liquid electrolyte comprising a non-aqueous solvent and a lithium salt, an inorganic solid electrolyte membrane, a polymer solid electrolyte membrane, a gel-type polymer electrolyte membrane, or a lithium ion conductive solid electrolyte membrane.
6. The protected anode of claim 1 , wherein the thickness ratio of the anode to the protective layer is in a range of about 0.001:1 to about 1,000:1.
7. A lithium air battery comprising:
the protected anode according to claim 1 ; and
a cathode comprising oxygen as a cathode active material.
8. The lithium air battery of claim 7 , further comprising, between the protected anode and the cathode, at least one interlayer of a separator, a liquid electrolyte comprising a non-aqueous solvent and a lithium salt, an inorganic solid electrolyte membrane, a polymer solid electrolyte membrane, a lithium ion conductive solid electrolyte membrane, or a gel-type polymer electrolyte membrane.
9. The lithium air battery of claim 8 , wherein the interlayer is a lithium ion conductive solid electrolyte membrane comprising a glass-ceramic solid electrolyte or a laminated structure of a glass-ceramic solid electrolyte and a polymer solid electrolyte.
10. The lithium air battery of claim 8 , wherein the interlayer is at least one separator comprising a polypropylene film, a polyethylene film, a polypropylene non-fabric, or a polyphenylene sulfide non-fabric.
11. The lithium air battery of claim 8 , wherein the interlayer is a liquid electrolyte comprising a non-aqueous solvent and a lithium salt.
12. The lithium air battery of claim 7 , wherein the cathode comprises a porous carbonaceous material.
13. An all-solid battery comprising the protected anode according to claim 1 .
14. The protected anode of claim 1 , wherein the thickness of the anode is in the range of about 10 to about 300 μm.
15. The protected anode of claim 1 , wherein the thickness of the protective layer is in the range of about 10 to about 500 μm.
16. The protected anode of claim 1 , wherein the combined thickness of the anode and the protective layer is in the range of about 20 to about 800 μm.
17. A protected anode comprising an anode comprising:
a lithium titanium oxide as an anode active material; and
a protective layer formed on the surface of the anode and comprising one of Li 1.3 Al 0.3 Ge 1.7 (PO 4 ) 3 , Li 1.4 Al 0.4 Ge 1.6 (PO 4 ) 3 , Li 1.5 Al 0.5 Ge 1.5 (PO 4 ) 3 , Li 1.6 Al 0.6 Ge 1.4 (PO 4 ) 3 , and Li 1.7 Al 0.7 Ge 1.3 (PO 4 ) 3 .