Anode material for all-solid secondary battery, anode layer and all-solid secondary battery including the same, and manufacturing method thereof
An anode material, an anode layer including the same, an all-solid secondary battery including the anode layer, and a method of manufacturing the all-solid secondary battery, the anode material including a metal-carbon composite, wherein the metal-carbon composite includes a carbon material; and metal particles, and the metal particles are dispersed and complexed in the carbon material, between particles of the carbon material, on a surface of the carbon material, or in two or more locations thereof.
1 . An anode material for all-solid secondary batteries, the anode material comprising a metal-carbon composite, wherein:
the metal-carbon composite includes:
a carbon material; and
metal particles,
the carbon material includes a carbonyl group, an ether group, a carboxylate group, an anhydride group, an aldehyde group, a lactone group, a phenol group, or a quinone group,
the metal particles are dispersed in the carbon material, between particles of the carbon material, on a surface of the carbon material, or in two or more locations thereof,
the metal particles form a complex with the carbon material through ionic or covalent bonding,
the metal-carbon composite has a metal-oxygen bond-related peak in a Raman spectrum,
in the Raman spectrum, the metal-oxygen bond-related peak exists at a Raman shift of about 200 cm −1 , about 470 cm −1 , or about 990 cm −1 , wherein the Raman spectrum is measured using a UV laser having a wavelength of about 514˜516 nm, and
in a case of performing thermogravimetric analyses on randomly selected multiple sites of the same sample, in each thermogravimetric analysis of the metal-carbon composite, when a straight line connecting points of respective weight percentages (%) at a thermal decomposition temperature of 500° C. and a final temperature at which no further weight loss occurs is expressed by a linear equation represented by Equation 1 below,
Y=−AX+B <Equation 1>
in Equation 1, X is a thermal decomposition temperature in° C., Y is a weight loss rate, −A is a slope, and B is a y-intercept, and
ΔA, which is a difference between values of A in each thermogravimetric analysis, is about 0.06 or less, and ΔB, which is a difference between values of B in each thermogravimetric analysis, is about 30 or less.
2 . The anode material as claimed in claim 1 , wherein, in X-ray diffraction (XRD) analysis obtained using CuKα rays, the metal-carbon composite has a 2theta value of at least one of about 35° to about 40°, about 40° to about 45°, about 60° to about 68°, about 75° to about 80°, and about 80° to about 85° in crystal peaks.
3 . The anode material as claimed in claim 1 , wherein, in each thermogravimetric analysis of the metal-carbon composite, a difference between values of the final temperature is about 30° C. or lower.
4 . The anode material as claimed in claim 1 , wherein the metal particles include silver, zinc, silicon, tin, or a combination thereof.
5 . The anode material as claimed in claim 1 , wherein the carbon material includes amorphous carbon, crystalline carbon, or a mixture thereof.
6 . The anode material as claimed in claim 5 , wherein
the amorphous carbon includes carbon black, vapor grown carbon fiber (VGCF), acetylene black (AB), active furnace black, or a combination thereof, and
the crystalline carbon includes natural graphite, artificial graphite, carbon nanotubes (CNT), graphene, or a combination thereof.
7 . The anode material as claimed in claim 1 , wherein the metal-carbon composite includes:
about 3 wt % to about 40 wt % of the metal particles, and
60 wt % to about 97 wt % of the carbon material, all wt % being based on a total weight of the carbon material and the metal particles.
8 . An anode composition for all-solid secondary batteries, the anode composition comprising:
the anode material as claimed in claim 1 ; and
an aqueous binder.
9 . An anode layer for all-solid secondary batteries, the anode layer comprising:
an anode current collector; and
a first anode active material layer on the anode current collector,
wherein the first anode active material layer includes the anode material as claimed in claim 1 .
10 . The anode layer as claimed in claim 9 , wherein:
in a case of performing thermogravimetric analyses on randomly selected multiple sites of one anode layer, in each thermogravimetric analysis of the anode layer, when a straight line connecting points of respective weight percentages (%) at a thermal decomposition temperature of 500° C. and a final temperature at which no further weight loss occurs is expressed by a linear equation represented by Equation 2 below,
Y=−A′X+B′ <Equation 2>
in Equation 2 above, X is a thermal decomposition temperature in° C., Y is a weight loss rate, −A′ is a slope, and B′is a y-intercept, and
ΔA′, which is a difference between values of A′ in each thermogravimetric analysis, is about 0.07 or less, and ΔB′, which is a difference between values of B′ in each thermogravimetric analysis, is about 50 or less.
11 . The anode layer as claimed in claim 9 , further comprising a metal or metalloid thin film between the anode current collector and the first anode active material layer.
12 . The anode layer as claimed in claim 11 , wherein
the metal or metalloid thin film includes gold (Au), silver (Ag), magnesium (Mg), zinc (Zn), silicon (Si), tin (Sn), platinum (Pt), palladium (Pd), aluminum (Al), bismuth (Bi), or a combination thereof, and
the metal or metalloid thin film has a thickness of about 1 nm to about 800 nm.
13 . The anode layer as claimed in claim 10 , further comprising a second anode active material layer, wherein the second anode active material layer includes lithium or a lithium alloy, and the lithium alloy includes a metal element, a metalloid element, or a combination thereof, the metal element or metalloid element being capable of forming an alloy with lithium.
14 . An all-solid secondary battery, comprising:
a cathode layer;
an anode layer; and
a solid electrolyte layer between the cathode layer and the anode layer,
wherein the anode layer is the anode layer as claimed in claim 13 .
15 . The all-solid secondary battery as claimed in claim 14 , wherein:
the anode layer further includes a second anode active material layer on the first anode active material layer or between the anode current collector and the first anode active material layer, and
the second anode active material layer includes lithium or a lithium alloy.
16 . The all-solid secondary battery as claimed in claim 14 , wherein the solid electrolyte layer includes an argyrodite-type sulfide solid electrolyte.
17 . The all-solid secondary battery as claimed in claim 16 , wherein the argyrodite-type sulfide solid electrolyte includes Li 6 PS 5 Cl, Li 6 PS 5 Br, or Li 6 PS 5 I.
18 . The anode material as claimed in claim 1 , wherein the metal particles are bonded to the carbon material through carboxylate groups.