Anode for secondary battery, secondary battery using same and method for fabricating anode
An anode for a secondary battery capable of inserting and extracting a lithium ion having a multi-layered structure including a first anode layer containing carbon as a main component; a second anode layer made of a film-like material through which a lithium component passes; and a third anode layer containing lithium and/or a lithium-containing compound as a main component. The battery capacity of the lithium ion battery is substantially increased while the higher charge-discharge efficiency and the stable cycle performance are maintained.
1. An anode for a secondary battery capable of inserting and extracting lithium ions, comprising:
a multi-layered structure including:
a first layer containing carbon as a main component;
a second layer made of a material for passing therethrough a lithium component and for inserting and extracting the lithium component, said material having a substantially uniform composition and an amorphous structure; and
a third layer containing lithium and/or a lithium-containing compound, the second layer being sandwiched between the first layer and the third layer.
2. The anode for the secondary battery as claimed in claim 1 wherein the second layer contains at least one material selected from the group consisting of B 2 O 3 , P 2 O 5 , Al 2 O 3 , W h O 3h-1 (h=1, 2, 3, 4), Mo i O 3i-1 (i=1, 2, 3, 4), TiO and TiO 2 .
3. The anode for the secondary battery as claimed in claim 1 , wherein the second layer contains at least one element selected from the group consisting of Si, Ge, Sn, In, Ag and Pb.
4. The anode for the secondary battery as claimed in claim 1 , wherein the second layer is made of one or more materials selected from the group consisting of oxides of Si, Ge, Sn, In, Ag and Pb.
5. An anode for a secondary battery capable of inserting and extracting lithium ions, comprising:
a multi-layered structure including:
a first layer containing carbon as a main component;
a second layer made of a material for passing therethrough a lithium component and for inserting and extracting the lithium component, said material having a substantially uniform composition; and
a third layer containing lithium and/or a lithium-containing compound, the second layer being sandwiched between the first layer and the third layer, and wherein the third layer has an amorphous structure.
6. The anode for the secondary battery as claimed in claim 1 , wherein the third layer contains at least one material selected from the group consisting of metal lithium, lithium alloy and lithium nitride.
7. A secondary battery, comprising:
an anode having a multi-layered structure, wherein said multi-layered structure includes:
a first layer containing carbon as a main component;
a second layer made of a material for passing therethrough a lithium component and for inserting and extracting the lithium component, said material having a substantially uniform composition and an amorphous structure; and
a third layer containing lithium and/or a lithium-containing compound, the second layer being sandwiched between the first layer and the third layer;
a cathode which can insert and extract a lithium ion; and
electrolyte placed between the anode and the cathode.
8. The secondary battery as claimed in claim 7 , wherein a ratio of a reversible capacity of the cathode with respect to a reversible capacity of the anode is in a range from 1.0 to 1.3.
9. The secondary battery as claimed in claim 7 , wherein the anode contains an excess lithium component with respect to its theoretical composition in a fully charged condition.
10. The secondary battery as claimed in claim 7 , wherein a total amount of the lithium component of the first layer and the second layer is larger than a sum of theoretical amounts of the lithium component of the first layer and the second layer in a fully charged condition.
11. The secondary battery as claimed in claim 7 , wherein the anode contains the lithium component larger than a sum of theoretical amounts of the lithium component of the first layer and the second layer in a fully charged condition.
12. The secondary battery as claimed in claim 7 , wherein the second layer contains at least one material selected from the group consisting of B 2 O 3 , P 2 O 5 , Al 2 O 3 , W h O 3h-1 (h=1, 2, 3, 4), Mo i O 3i-1 (i=1, 2, 3, 4), TiO and TiO 2 .
13. The secondary battery as claimed in claim 7 , wherein the second layer contains at least one element selected from the group consisting of Si, Ge, Sn, In, Ag and Pb.
14. The secondary battery as claimed in claim 7 , wherein the second layer is made of one or more materials selected from the group consisting of oxides of Si, Ge, Sn, In, Ag and Pb.
15. A secondary battery, comprising:
an anode having a multi-layered structure, wherein said multi-layered structure includes:
a first layer containing carbon as a main component;
a second layer made of a material for passing therethrough a lithium component and for inserting and extracting the lithium component, said material having a substantially uniform composition; and
a third layer containing lithium and/or a lithium-containing compound, the second layer being sandwiched between the first layer and the third layer, wherein the third layer has an amorphous structure;
a cathode which can insert and extract a lithium ion; and
electrolyte placed between the anode and the cathode.
16. The anode for the secondary battery as claimed in claim 7 , wherein the third layer contains at least one material selected from the group consisting of metal lithium, lithium alloy and lithium nitride.