All-solid-state secondary battery including anode active material alloyable with lithium and method of charging the same
An all-solid-state secondary battery including: a cathode including a cathode active material layer; an anode including an anode current collector, and an anode active material layer on the anode current collector, wherein the anode active material layer includes an anode active material which is alloyable with lithium or forms a compound with lithium; and a solid electrolyte layer between the cathode and the anode, wherein a ratio of an initial charge capacity (b) of the anode active material layer to an initial charge capacity (a) of the cathode active material layer satisfies a condition of Equation 1: 0.01<(b/a)<0.5, wherein a is the initial charge capacity of the cathode active material layer determined from a first open circuit voltage to a maximum charging voltage, and b is the initial charge capacity of the anode active material layer determined from a second open circuit voltage to 0.01 volts vs. Li/Li + .
1. An all-solid-state secondary battery comprising:
a cathode comprising a cathode active material layer;
an anode comprising
an anode current collector, and
an anode active material layer on the anode current collector, wherein the anode active material layer comprises an anode active material which is alloyable with lithium or forms a compound with lithium; and
a solid electrolyte layer between the cathode and the anode,
wherein a ratio of an initial charge capacity of the anode active material layer to an initial charge capacity of the cathode active material layer satisfies Equation 1
0.01<( b/a )<0.5 Equation 1
wherein a is the initial charge capacity of the cathode active material layer, determined from a first open circuit voltage to a maximum charging voltage vs. Li/Li + , and
wherein b is the initial charge capacity of the anode active material layer, determined from a second open circuit voltage to 0.01 Volts vs. Li/Li + .
2. The all-solid-state secondary battery of claim 1 , wherein the anode active material layer comprises the anode active material and a binder.
3. The all-solid-state secondary battery of claim 2 , wherein an amount of the binder ranges from about 0.3 weight percent to about 15 weight percent, based on a total weight of the anode active material.
4. The all-solid-state secondary battery of claim 2 , wherein the anode active material layer has a thickness of about 1 micrometer to about 20 micrometers.
5. The all-solid-state secondary battery of claim 1 , wherein the anode active material is in a form of a particle, and wherein the anode active material has an average particle diameter of about 4 micrometers or less.
6. The all-solid-state secondary battery of claim 1 , wherein the anode active material comprises at least one of amorphous carbon, gold, platinum, palladium, silicon, silver, aluminum, bismuth, tin, or zinc.
7. The all-solid-state secondary battery of claim 6 , wherein the anode active material comprises the amorphous carbon, and
at least one of gold, platinum, palladium, silicon, silver, aluminum, bismuth, tin, or zinc.
8. The all-solid-state secondary battery of claim 1 , wherein the anode active material is amorphous carbon.
9. The all-solid-state secondary battery of claim 1 , wherein the anode active material comprises a mixture of a first particle comprising amorphous carbon and a second particle comprising at least one of a metal or a semiconductor, and
wherein an amount of the second particle is about 8 weight percent to about 60 weight percent, based on a total weight of the mixture.
10. The all-solid-state secondary battery of claim 1 , further comprising a plating layer on the anode current collector, the plating layer comprising an element which is alloyable with lithium,
wherein the plating layer is between the anode current collector and the anode active material layer.
11. The all-solid-state secondary battery of claim 10 , wherein the plating layer has a thickness of about 1 nanometer to about 500 nanometers.
12. The all-solid-state secondary battery of claim 1 , further comprising a metal layer between the anode current collector and the anode active material layer, wherein the metal layer comprises at least one of lithium or a lithium alloy.
13. The all-solid-state secondary battery of claim 12 , wherein the metal layer is between the anode current collector and the anode active material layer before the all-solid-state secondary battery is charged.
14. The all-solid-state secondary battery of claim 12 , wherein the metal layer has a thickness of about 1 micrometer to about 200 micrometers.
15. The all-solid-state secondary battery of claim 1 , wherein the anode current collector, the anode active material layer, and a region therebetween are Li-free regions at an initial state of or after discharge of the all-solid-state secondary battery.
16. The all-solid-state secondary battery of claim 1 , wherein the all-solid-state secondary battery is a lithium battery.
17. The all-solid-state secondary battery of claim 1 , wherein the maximum charging voltage is about 3 volts to about 5 volts versus Li/Li + .
18. The all-solid-state secondary battery of claim 17 , wherein the maximum charging voltage is about 4.2 volts to about 5 volts versus Li/Li + .
19. An all-solid-state secondary battery comprising:
a cathode;
an anode; and
a solid electrolyte layer,
wherein the cathode comprises a cathode active material layer,
wherein the anode comprises an anode current collector and an anode active material layer on a surface of the anode current collector, wherein the anode active material layer comprises a binder and an anode active material comprising amorphous carbon,
wherein the solid electrolyte layer is arranged between the cathode active material layer and the anode active material layer, and
wherein a ratio of an initial charge capacity of the anode active material layer to an initial charge capacity of the cathode active material layer satisfies Equation 1:
0.01<( b/a )<0.5 Equation 1
wherein a is the initial charge capacity of the cathode active material layer, determined from a first open circuit voltage to a maximum charging voltage vs. Li/Li + , and
wherein b is the initial charge capacity of the anode active material layer, determined from a second open circuit voltage to 0.01 volts vs. Li/Li + .
20. The all-solid-state secondary battery of claim 19 , wherein the amorphous carbon comprises furnace black, acetylene black, Ketjen black, graphene, or a combination thereof.
21. The all-solid-state secondary battery of claim 19 wherein the amorphous carbon is in the form of a particle and comprises an average particle diameter D50 of about 4 micrometers or less.
22. The all-solid-state secondary battery of claim 19 , wherein the anode active material further comprises a second particle.
23. The all-solid-state secondary battery of claim 22 , wherein a weight ratio of the amorphous carbon to the second particle is about 20:1 to about 1:2.
24. The all-solid-state secondary battery of claim 22 , wherein the second particle comprises platinum, silicon, silver, tin, zinc, or a combination thereof.
25. The all-solid-state secondary battery of claim 22 , wherein the second particle comprises silver, tin, zinc, or a combination thereof.
26. The all-solid-state secondary battery of claim 19 , wherein the binder comprises styrene butadiene rubber, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, or a combination thereof.
27. The all-solid-state secondary battery of claim 19 , further comprising a film disposed on the anode current collector and between the anode current collector and the anode active material layer, the film comprising lithium or an element alloyable with lithium.
28. The all-solid-state secondary battery of claim 19 , wherein the ratio of the initial charge capacity of the anode active material layer to the initial charge capacity of the cathode active material layer satisfies a condition of Equation 1A:
0.01<( b/a )<0.25 Equation 1A.
29. The all-solid-state secondary battery of claim 19 , wherein the ratio of the initial charge capacity of the anode active material layer to the initial charge capacity of the cathode active material layer satisfies a condition of Equation 1B:
0.01<( b/a )<0.2 Equation 1B.
30. The all-solid-state secondary battery of claim 19 , wherein the ratio of the initial charge capacity of the anode active material layer to the initial charge capacity of the cathode active material layer satisfies a condition of Equation 1C:
0.01<( b/a )<0.1 Equation 1C.
31. A method of charging the all-solid-state secondary battery, the method comprising:
charging the all-solid-state secondary battery of claim 1 ,
wherein the initial charge capacity of the anode active material layer is exceeded.
32. The method of claim 31 , wherein a charge capacity of the all-solid-state secondary battery is about two times to about 100 times greater than the initial charge capacity of the anode active material layer.