Anode protective layer comprising multi-sublayers and all solid-state battery comprising same

Abstract

Disclosed is an all solid-state battery (ASSB) comprising an anode layer, an anode protective layer, a solid electrolyte layer, and a cathode layer in the order, wherein the protective layer comprises a first sublayer adjacent to the anode layer; and a second sublayer between the SE layer and the first sublayer, wherein each sublayer comprises a carbonaceous material, and the second sublayer contains a lithium alloyable material with a content greater than that in the first sublayer. In some embodiments, the ASSB comprising the anode protective layer exhibits an improved electrochemical performance.

Description

ANODE PROTECTIVE LAYER COMPRISING MULTI- SUBLAYERS AND ALL SOLID- STATE BATTERY COMPRISING SAMECROSS-REFERENCE

[0001] The present application claims the benefit of US Serial No. 63 / 673,022, July 18, 2024, and US Serial No. 63 / 663,376, filed June 24, 2024, the entire content of which is incorporated herein by reference into this application.FIELD

[0002] The present disclosure is generally related to for an all solid- state battery (ASSB) comprising an anode protective layer.BACKGROUND

[0003] All-solid-state batteries (ASSBs) are being extensively studied due to their better safety and higher energy density in comparison to liquid-electrolyte based lithium-ion batteries. ASSBs include a solid electrolyte (SE) layer between a cathode layer and an anode layer, wherein the SE layer comprises an inorganic ion conductor such as inorganic oxide or sulfide electrolyte. The SE layer functions as both electrolyte and separator. However, formation and growth of lithium dendrite may penetrate an SE layer and cause short-circuit, thus leading to a shortened life of ASSB. Thus, there remains a need for new ASSBs and methods for preparing the same.SUMMARY

[0004] The present disclosure provides an all solid-state battery (ASSB) comprising an anode layer, an anode protective layer, a solid electrolyte layer, and a cathode layer in the order, wherein the anode protective layer comprises a first sublayer adjacent to the anode layer and a second sublayer between the SE layer and the first sublayer, wherein each sublayer comprises a carbonaceous material, and the second sublayer contains a lithium alloyable material with a content greater than that in the first sublayer. In some embodiments, the ASSB comprising the anode protective layer exhibits an improved electrochemical performance. In someembodiments, the anode layer comprises an anode active material layer and an anode current collector. In some embodiments, the anode layer comprises an anode current collector without an anode active material layer. An anode protective layer is a layer (interlayer), either a single layer or multiple sublayers, disposed between the SE layer and an anode layer. In some embodiments, the anode active material layer is formed on the anode current collector after a first time charge. Without wishing to be bound by any theory, an anode protective layer may protect the anode layer, SE layer or both.BRIEF DESCRIPTION OF THE FIGURES

[0005] Non-limiting embodiments of the present disclosure will be described by way of example with reference to the accompanying figures, which are schematic and are not intended to be drawn to scale. In the figures, each identical or nearly identical component illustrated is typically represented by a single numeral. For purposes of clarity, not every component is labeled in every figure, nor is every component of each embodiment of the disclosure shown where illustration is not necessary to allow those of ordinary skill in the art to understand the disclosure.

[0006] Fig. 1 illustrates a representative configuration of an AS SB with an anode protective layer comprising two sublayers according to one embodiment of the present disclosure.

[0007] Fig. 2 illustrates another representative configuration of an AS SB with an anode protective layer comprising two sublayers according to one embodiment of the present disclosure.

[0008] Fig. 3 illustrates a representative configuration of an AS SB with an anode protective layer according to one embodiment of the present disclosure.

[0009] Fig. 4 shows an SEM image of a cross-section of an AS SB according to one embodiment of the present disclosure.

[0010] Fig. 5 shows an SEM image of a cross-section of an ASSB according to another embodiment of the present disclosure.

[0011] Fig. 6 shows an SEM image of a cross-section of an ASSB according to another embodiment of the present disclosure.

[0012] Figs. 7A through 7G show the rate performance of cells according to some embodiments of the present disclosure.

[0013] Figs. 8A, 8B and 8C show the specific capacities, capacity retention rates and columbic efficiencies (CEs) of cells during cycling, respectively, according to some embodiments of the present disclosure.DETAILED DESCRIPTION

[0014] Disclosed is an all solid-state battery (ASSB) comprising a cathode layer, a solid electrolyte layer, an anode protective layer and an anode layer in the order, wherein the anode protective layer comprises a first sublayer adjacent to the anode layer and a second sublayer between the first sublayer and the SE layer, each sublayer comprises a carbonaceous material, and the second sublayer contains a lithium alloyable material with a content greater than that in the first sublayer. In some embodiments, the ASSB comprising the anode protective layer exhibits a longer cycling life and an improved electrochemical performance.

[0015] In some embodiments, the content of the lithium alloyable material refers to a weight percentage within a layer or sublayer based on the total weight of the layer or sublayer. In some embodiments, the content of the lithium alloy able material refers to a weight percentage within a certain portion of a layer or sublayer.

[0016] In one embodiment, an ASSB comprises a cathode layer (1), an anode layer (2), a solid electrolyte (SE) layer (3), and an anode protective layer (4) between the SE layer (3) and the anode (2) as shown in Figs. 1 and 2. In some embodiments, the anode protective layer (4) comprises a first sublayer (4-1) adjacent to the anode layer (2) and a second sublayer (4-2) between the SE layer (3) and the first sublayer (4-1), wherein the first sublayer (4-1) comprises a lithium alloyable material, and the second sublayer (4-2) contains the lithium alloyable material with a content greater than the first sublayer. In some embodiments, the anode layer(2) comprises an anode current collector (2-1) and optionally an anode active material layer (2- 2). In some embodiments, the first sublayer (4-1) is adjacent to the anode active material layer (2-2) of the anode layer (2) as shown in Fig. 1. In some embodiments, the first sublayer (4-1) is adjacent to the anode current collector (2-1) of the anode layer (2) which does not include an anode active material layer (2-2) prior to the first charge as shown in Fig. 2. In some embodiments, the cathode layer (1) comprises a cathode current collector (1-1) and a cathode active material layer (1-2).

[0017] In some embodiments, the anode layer (2) comprises an anode current collector (2-1). In some embodiments, an anode active material layer (2-2) is assembled into an ASSB prior to the first charge. In some embodiments, an anode active material layer (2-2) is formed after the first charge.

[0018] In some embodiments, the first sublayer (4-1) contains a lithium alloyable material with a content greater than zero and lower than the second sublayer (4-2). In some embodiments, the first sublayer (4-1) does not contain any lithium alloyable material, i.e., the content is zero.

[0019] In some embodiments, the anode protective layer (4) is but without limited to a multilayered structure. In some embodiments, the anode protective layer (4) is a single layer with different content of the lithium alloyable material along the thickness direction. As shown in Fig. 3, the anode protective layer (4) is a single layer, wherein the lithium alloyable material (5) has a content (or concentration) close to the solid electrolyte layer (3) higher than that close to the anode layer (2). In some embodiments, the lithium alloyable material (5) exhibits a gradient content (or concentration) along the thickness direction of the anode protective layer (4), wherein the lithium alloyable material content close to the solid electrolyte layer (3) is the highest and the content close to the anode layer (2) is the lowest. In some embodiments, the lithium alloyable material content close to the anode layer (2) is zero or near zero.

[0020] In some embodiments, the anode protective layer (4) may have two or more sublayers.[0021| In some embodiments, the carbonaceous material in the anode protective layer comprises at least one selected from the group consisting of carbon black, carbon fiber, carbon nanotubes, acetylene black, Ketjen black, channel black, furnace black, lamp black, thermal black, natural graphite, artificial graphite, chemically reduced graphene oxide (cr-GO), and mixtures thereof. In some embodiments, the lithium alloyable material comprises at least one selected from the group consisting of Ag, Zn, Ti, Cd, Mg, Al, Ga, Si, Ge, In, Sn, Pb, Bi, and Sb. In some embodiments, the lithium alloyable material is in the form of particles. In some embodiments, the particles of the lithium alloyable material have a median particle size (D50) in a range from 20 nm to 150 nm in the anode protective layer. In some embodiments, the particles of the lithium alloyable material are evenly distributed in a matrix of the carbonaceous material in the first sublayer, the second sublayer, or both in the anode protective layer.

[0022] In some embodiments, the first and second sublayers of the anode protective layer each independently have a thickness in a range from 0.2 pm to 50.0 pm, from 0.2 pm to 40.0 pm, from 0.2 pm to 30.0 pm, from 0.2 pm to 20.0 pm, from 0.2 pm to 15.0 pm, from 0.2pm to 10.0 pm, from 0.2pm to 5.0 pm, from 0.5 pm to 50.0 pm, from 0.5 pm to 40.0 pm, from 0.5 pm to 30.0 pm, from 0.5 pm to 20.0 pm, from 0.5 pm to 15.0 pm, from 0.5pm to 10.0 pm, from 0.5pm to 5.0 pm, from 1.0 pm to 50.0 pm, from 1.0 pm to 40.0 pm, from 1.0 pm to 30.0 pm, from 1.0 pm to 20.0 pm, from 1.0 pm to 15.0 pm, from 1.0 pm to 10.0 pm, from 1.0 pm to 5.0 pm, or any and all subranges and ranges therebetween.

[0023] In some embodiments, the anode protective layer has an overall thickness in a range from 0.5 pm to 50.0 pm, from 0.5 pm to 40.0 pm, from 0.5 pm to 30.0 pm, from 0.5 pm to 20.0 pm, from 0.5 pm to 15.0 pm, from 0.5pm to 10.0 pm, from 0.5pm to 5.0 pm, from 1.0 pm to 50.0 pm, from 1.0 pm to 40.0 pm, from 1.0 pm to 30.0 pm, from 1.0 pm to 20.0 pm, from 1.0 pm to 15.0 pm, from 1.0 pm to 10.0 pm, from 1.0 pm to 5.0 pm, or any and all subranges and ranges therebetween.[00241 In some embodiments, the carbonaceous material in each sublayer has a volume percentage of at least 50%, at least 60% or at least 70% so that the particles of the lithium alloyable material are distributed in a matrix of the carbonaceous material.

[0025] A solid electrolyte layer (alternatively, solid electrolyte membrane or electrolyte film) refers to a thin structure that allows transportation or flow of ions and prevents electronic contact between a cathode and an anode. A solid electrolyte layer has a typical thickness in a range from 5 pm to 300 pm.

[0026] In some embodiments, the solid electrolyte is an oxide-based solid electrolyte or a sulfide-based electrolyte. In one embodiment, the solid electrolyte has a formula LixMlyM2zPi-PM3pS6-a-b-qOqClaBrb (Formula I), wherein 4<x<8, 0<y<l, 0<z <1, 0<p<l, 0<q<l, 0<a<2, 0<b<2, 0<6-a-b-q<6, 0<l-p<l, wherein Ml is at least one element of Group 1 or Group 11 other than H or Li of the periodic table, M2 is at least one element of Group 2 of the periodic table, and M3 is at least one element of Group 14 of the periodic table.

[0027] In some embodiments, the solid electrolytes has a formula LixMlyM2zPi-PM3PS6-a-b- qOqClaBrb (Formula I), wherein 4<x<8, 0<y<l, 0<z <1, 0<p<l, 0<q<l, 0<a<2, 0<b<2, 0<6-a- b-q<6, 0<l -p<l , and wherein Ml is at least one element of Group 1 or Group 11 other than H or Li of the periodic table, M2 is at least one element of Group 2 of the periodic table, and M3 is at least one element of Group 14 of the periodic table.

[0028] In some embodiments, Ml is at least one selected from the group consisting of Na, K, Rb, Cs, Cu, Ag, and Au. In some embodiments, M2 is at least one selected from the group consisting of Be, Mg, Ca, Sr, and Ba. In some embodiments, M3 is at least one selected from the group consisting of Si, Ge, Sn, and Pb.

[0029] In some embodiments, b / a has a value in a range from 0 to 20, i.e., 0<b / a<20.

[0030] In some embodiments, the formula of sulfide solid electrolyte in the electrolyte layer, i.e., LixMlyM2zPi-pM3pS6-a-b-qOqClaBrb, does not comprise any of Ml, M2, M3 or O, i.e., y=z=p=q=0, corresponding to a formula of LixPS6-a-bClaBrb.[0031| In some embodiments, the formula of the sulfide electrolyte comprises at least one element selected from the group consisting of Ml, M2, M3 and O. In some embodiments, the Formula (I) contains one element selected from the group consisting of Ml, M2, M3 and O. In some embodiments, Formula I is selected from the group consisting of:1) LixMlyPSe-a-bClaBrb, where 4<x<8, 0<y<l, 0<a<2, 0<b<2, 0<6-a-b<6;2) LixM2zPS6-a-bClaBrb, where 4<x<8, 0<z<l, 0<a<2, 0<b<2, 0<6-a-b<6;3) LixPi-pM3pS6-a-bClaBrb, where 4<x<8, 0<p<l, 0<a<2, 0<b<2, 0<6-a-b<6, 0<l-p<l; and4) LixPSe-a-b-qOqClaBrb, where 4<x<8, 0<q<l, 0<a<2, 0<b<2, 0<6-a-b-q<6.

[0032] In some embodiments, the Formula (I) contains O and one element selected from the group consisting of Ml, M2, and M3. In some embodiments, the sulfide solid electrolyte has a formula selected from the group consisting of LixMlyPSe-a-b-qOqClaBrb (4<x<8, 0<y< 10<q<l, 0<a<2, 0<b<2, 0<6-a-b-q<6), LixM2zPiS6-a-b-qOqClaBrb (4<x<8, 0<z<l, 0<q<l, 0<a<2, 0<b<2, 0<6-a-b-q<6,), and LixPi-pM3pS6-a-b-qOqClaBrb (4<x<8, 0<p<l, 0<q<l, 0<a<2, 0<b<2, 0<6-a-b-q<6, 0<l-p<l). In one embodiment, the Formula (I) contains O without Ml, M2, or M3. In one embodiment, the formula of the sulfide electrolyte is LixPSe-a-b-qOqClaBrb (4<x<8, 0<q<l, 0<a<2, 0<b<2, 0<6-a-b-q<6). In some embodiments, Ml is at least one element of Group 1 or Group 11 other than H or Li of the periodic table. In some embodiments, Ml is at least one selected from the group consisting of Na, K, Rb, Cs, Cu, Ag, and Au. In some embodiments, M2 is at least one element of Group 2 of the periodic table. In some embodiments, M2 is at least one selected from the group consisting of Be, Mg, Ca, Sr, and Ba. In some embodiments, M3 is at least one element of Group 14 of the periodic table. In some embodiments, M3 is at least one selected from the group consisting of Si, Ge, Sn, and Pb.

[0033] In one embodiment, the sulfide solid electrolyte has a formula of LixPSe-a-b-qOqClaBrb, where 4<x<8, 0<q<l, 0<a<2, 0<b<2, 0<6-a-b-q<6. The incorporation of oxygen into the formula makes such material more stable. In some embodiments, the molar amount of O with q having a value in a range from 0 to 0.1, from 0 to 0.2, from 0 to 0.3, from 0 to 0.4, from 0 to0.5, from 0 to 0.6, from 0.001 to 0.1, from 0.001 to 0.2, from 0.001 to 0.3, from 0.001 to 0.4, from 0.001 to 0.5, from 0.001 to 0.6, from 0.002 to 0.1, from 0.002 to 0.2, from 0.002 to 0.3, from 0.002 to 0.4, from 0.002 to 0.5, from 0.002 to 0.6, from 0.005 to 0.1, from 0.005 to 0.2, from 0.005 to 0.3, from 0.005 to 0.4, from 0.005 to 0.5, from 0.005 to 0.6, or any and all ranges and subranges therebetween. In one embodiment, the formula is Li5.8PS4.70o.iCli.2.[00341 In some embodiments, the formula is LixPSe-a-b-qOqClaBrb, wherein 4<x<8, 0<q<l, 0<a<2, 0<b<2, 0<6-a-b-q<6. In some embodiments, b / a has a value higher than zero. In some embodiments, b / a has a value in a range from 0 to 3.5. In some embodiments, b / a has a value in a range from 0 to 7. In some embodiments, b / a has a value in a range from 0 to 10, from 0 to 15, or from 0 to 20.

[0035] In some embodiments, when the formula is LixMlyPSe-a-b-qClaBrb, 4<x<8, 0<y<l, 0<a<2, 0<b<2, 0<6-a-b<6, b / a has a value in a range from 0 to 3.5. In some embodiments, b / a has a value in a range from 0 to 7. In some embodiments, b / a has a value in a range from 0 to 10, from 0 to 15, or from 0 to 20. In some embodiments, b / a has a value higher than zero.

[0036] In some embodiments, when the formula is LixM2zPS6-a-bClaBrb, where 4<x<8, 0<z<l, 0<a<2, 0<b<2, 0<6-a-b<6, b / a has a value in a range from 0 to 3.5. In some embodiments, b / a has a value in a range from 0 to 7. In some embodiments, b / a has a value in a range from 0 to 10, from 0 to 15, or from 0 to 20. In some embodiments, b / a has a value higher than zero.

[0037] In one embodiment, when the formula is LixPi-pM3PS6-a-bClaBrb, 4<x<8, 0<p<l, 0<a<2, 0<b<2, 0<6-a-b<6, 0<l-p<l, b / a has a value in a range from 0 to 3.5. In some embodiments, b / a has a value in a range from 0 to 7. In some embodiments, b / a has a value in a range from 0 to 10, from 0 to 15, or from 0 to 20. In some embodiments, b / a has a value higher than zero.

[0038] In some embodiments, the Formula (I) contains O and one element selected from the group consisting of Ml, M2, and M3. In some embodiments, the sulfide solid electrolyte has a formula selected from the group consisting of LixMlyPSe-a-b-qOqClaBrb (4<x<8, 0<y<l,0<q<l, 0<a<2, 0<b<2, 0<6-a-b-q<6), LixM2zPS6-a-b-qOqClaBrb (4<x<8, 0<z<l, 0<q<l, 0<a<2, 0<b<2,0<6-a-b-q<6,), and LixPi-pM3pS6-a-b-qOqClaBrb (4<x<8, 0<p<l, 0<q<l, 0<a<2, 0<b<2, 0<6-a- b-q<6, 0<l-p<l). In one embodiment, the Formula (I) contains O without Ml, M2, or M3. In one embodiment, the formula of the sulfide electrolyte is LixPSe-a-b-qOqClaBrb (4<x<8, 0<q<l, 0«2. 0<b<2, 0<6-a-b-q<6). In some embodiments, the molar amount of Br in the formula has a value higher than zero, i.e., b>0.

[0039] In some embodiments, the total molar amount of the halogen in the formula of sulfide electrolyte is no more than 2, i.e., a+b<2. In one embodiment, the total molar amount of the halogen in the formula is no less than 2 and no more than 3, i.e., 2<a+b<3. In one embodiment, the total molar amount of the halogen in the formula is no less than 2 and less than 4, i.e., 2<a+b<4. In one embodiment, the total molar amount of Br and Cl in the formula is no more than 2, i.e., a+b<2, no less than 2 and no more than 3, i.e., 2<a+b<3, or no less than 2 and less than 4, i.e., 2<a+b<4.

[0040] In some embodiments, the sulfide solid electrolyte has a formula selected from the group consisting of:1) LixPSe-a-bClaBrb, where 4<x<8, 0<a<2, 0<b<2, 0<6-a-b<6;2) LixMlyPSe-a-bClaBrb, where 4<x<8, 0<y<l, 0<a<2, 0<b<2, 0<6-a-b<6;3) LixM2zPS6-a-bClaBrb, where 4<x<8, 0<z<l, 0<a<2, 0<b<2, 0<6-a-b<6;4) LixPi-pM3pS6-a-bClaBrb, where 4<x<8, 0<p<l, 0<a<2, 0<b<2, 0<6-a-b<6, 0<l-p<l;5) LixPSe-a-b-qOqClaBrb, where 4<x<8, 0<q<l, 0<a<2, 0<b<2, 0<6-a-b-q<6;6) LixMlyPSe-a-b-qOqClaBrb, where 4<x<8, 0<y<l,0<q<l, 0<a<2, 0<b<2, 0<6-a-b-q<6;7) LixM2zPS6-a-b-qOqClaBrb, where 4<x<8, 0<z<l, 0<q<l, 0<a<2, 0<b<2, 0<6-a-b-q<6;8) LixPi-pM3pS6-a-b-qOqClaBrb, where 4<x<8, 0<p<l, 0<q<l, 0<a<2, 0<b<2, 0<6-a-b-q<6, 0<l-p<l; and9) mixtures thereof.

[0041] In some embodiments, the solid electrolyte layer has a thickness in a range from 5 pm to 300 pm, from 10 pm to 300 pm, from 20 pm to 300 pm, from 50 pm to 300 pm, from 5 pmto 200 pm, from 10 pm to 200 pm, from 20 pm to 200 pm, from 50 pm to 200 pm, from 5 pm to 100 pm, from 10 pm to 100 pm, from 20 pm to 100 pm, from 50 pm to 100 pm, from 5 pm to 50 pm, from 10 pm to 50 pm, from 20 pm to 50 pm, or any and all ranges and subranges therebetween.

[0042] In some embodiments, the solid electrolyte layer has a lithium-ion conductivity of no less than 0.05 mS / cm, no less than 0.1 mS / cm, no less than 0.2 mS / cm, no less than 0.5 mS / cm, no less than 0.75 mS / cm, no less than 1 mS / cm, no less than 2 mS / cm, or no less than 5 mS / cm, no less than 7.5 mS / cm or no less than 10 mS / cm. In some embodiments, the solid electrolyte layer has a lithium-ion conductivity in a range from 0.05 mS / cm to 10 mS / cm, from 0.1 mS / cm to 10 mS / cm, from 0.25 mS / cm to 10 mS / cm, from 0.5 mS / cm to 10 mS / cm, from 0.75 mS / cm to 10 mS / cm, from 1 mS / cm to 10 mS / cm, from 2 mS / cm to 10 mS / cm, from 0.05 mS / cm to 7.5 mS / cm, from 0.1 mS / cm to 7.5 mS / cm, from 0.25 mS / cm to 7.5 mS / cm, from 0.5 mS / cm to 7.5 mS / cm, from 0.75 mS / cm to 7.5 mS / cm, from 1 mS / cm to 7.5 mS / cm, from 2 mS / cm to 7.5 mS / cm, from 0.05 mS / cm to 5 mS / cm, from 0.1 mS / cm to 5 mS / cm, from 0.25 mS / cm to 5 mS / cm, from 0.5 mS / cm to 5 mS / cm, from 0.75 mS / cm to 5 mS / cm, from 1 mS / cm to 5 mS / cm, or any and all ranges and subranges therebetween.

[0043] In one embodiment, the cathode active material layer of an ASSB comprises a cathode active material. In some embodiments, the ASSB has a relatively high cathode loading. In some embodiments, the ASSB has a cathode loading of at least 5.0 mAh / cm2, at least 5.5 mAh / cm2, at least 6.0 mAh / cm2, at least 6.5 mAh / cm2, at least 6.8 mAh / cm2, at least 7.2 mAh / cm2, or at least 7.5 mAh / cm2. A high cathode loading is critical to achieve a high energy density. However, a battery with a high cathode loading may be subject to a relatively fast decay, which ultimately leads to a lower capacity retention. In some embodiments, the present disclosure provides an ASSB having both a high cathode loading and a good cycling performance.

[0044] In some embodiments, the ASSB comprising the anode protective layer exhibits a cycling life of at least 10% higher, at least 15% higher, at least 20% higher, at least 25% higher,at least 30% higher, at least 35% higher, at least 40% higher, at least 45% higher, or at least 50% higher than that of one comprising an electrolyte layer without multiple sublayer structure.

[0045] In some embodiments, the AS SB exhibits an initial specific capacity of at least 200 mAh / g at a rate of 0.1C at a temperature of 45 °C. In some embodiments, the ASSB is tested at a pressure in a range from 0.5 MPa to 5.0 MPa.

[0046] In some embodiments, the cycling test can be performed at other C rates such as C / 6, C / 4, C / 2, C, 1C, 2C, 3C, 5C, or any intermediate rate therebetween. In some embodiments, the cycling test can be performed at other temperatures such as -20°C, -10°C, 0°C, 10°C, 20°C 25°C, 30 °C, 40°C, 50°C, 80 °C, or any intermediate temperature therebetween. Cycle life is determined by the number of cycles for the battery cell to reach a threshold value such as 80% of its original capacity and is usually used to measure the cycling performance of a secondary battery. In some embodiments, the ASSB comprising the anode assembly exhibits a cycle life which is at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 40%, at least 50%, or at least 60% longer than that of the ones with an anode protective layer wherein the second sublayer contains the lithium alloyable material with a content equal to or lower than that in the first sublayer.

[0047] In some embodiments, the ASSB exhibits a capacity retention rate of at least 98.00%, at least 98.25%, at least 98.50%, at least 98.75%, at least 99.00%, at least 99.25%, at least 99.50%, at least 99.75%, at least 99.80%, or at least 99.90% after at least 50 cycles at a rate of 0.33C / 0.33C at 45 °C.

[0048] In some embodiments, the ASSB exhibits a capacity retention rate of at least 94.00%, at least 95.00%, at least 96.00%, at least 97.00%, at least 98.00%, at least 98.50%, at least 99.00%, at least 99.50%, at least 99.75% or at least 99.90% after at least 100 cycles at a rate of0.33C / 0.33C at 45 °C.

[0049] In some embodiments, after 50 cycles at a rate of 0.33C / 0.33C at a temperature of 45 °C, the AS SB exhibits a specific capacity of at least 160 mAh / g, at least 163 mAh / g, at least 165 mAh / g, at least 168 mAh / g, or at least 170 mAh / g.[00501 In some embodiments, after 100 cycles at a rate of 0.33C / 0.33C at a temperature of 45 °C, the ASSB exhibits a specific capacity of at least 150 mAh / g, at least 153 mAh / g, at least 155 mAh / g, at least 158 mAh / g, at least 160 mAh / g, at least 163mAh / g, at least 165 mAh / g, at least 168 mAh / g or at least 170 mAh / g.

[0051] In some embodiments, the ASSB exhibits an average CE of an average CE of at least 99.75%, at least 99.77%, at least 99.80%, or at least 99.82% for the first 50 cycles at a rate of 0.33C / 0.33C at a temperature of 45 °C,

[0052] In some embodiments, the ASSB exhibits an average CE of an average CE of at least 99.80%, at least 99.82%, at least 99.85%, at least 99.87%, at least 99.90% for the first 100 cycles at a rate of 0.33C / 0.33C at a temperature of 45 °C,

[0053] In one embodiment, the cathode active material layer in the cathode layer of an ASSB comprises a cathode electroactive material. In one embodiment, the cathode active material contains Li, Ni, and Co. In one embodiment, the cathode active material contains Li, Ni, and Co and at least one of Mn and Al. In one embodiment, the cathode active material contains at least one of Fe, and P.

[0054] In one embodiment, the cathode active material experiences a redox reaction at a potential of 2 V or above over Li / Li+ during operation of an ASSB.

[0055] In some embodiments, the anode active material layer comprises an anode active material such as lithium metal or a lithium alloy. In some embodiments, the anode active material comprises at least one selected from the group consisting of lithium, sodium, magnesium, aluminum, silicon, calcium, titanium, manganese, iron, cobalt, nickel, zinc, molybdenum, silver, indium, tin, and tungsten. In some embodiments, the anode active material layer also includes a carbon-based conductive material with a weight percentage in a rangefrom lwt% to 30wt%. In some embodiments, the carbon-based conductive material in the anode active material layer comprises at least one selected from the group consisting of carbon black, acetylene black, Ketjen black, channel black, furnace black, lamp black, thermal black, natural graphite and artificial graphite.

[0056] In one aspect, the present disclosure provides a method for preparing an anode protective layer. The method comprises:1) Coating a first slurry onto an anode current collector such as stainless steel (SUS) followed by drying, wherein the first slurry comprises a carbonaceous material and particles of a lithium alloyable material, leading to a first coating with a first content on the anode current collector, and2) Applying a second slurry onto the first coating followed by a second drying, wherein the second slurry comprises the carbonaceous material and particles of the lithium alloyable material, thereby obtaining a second coating on the first coating of the anode current collector, wherein the lithium alloyable material in the second coating has a second content higher than the first content in the first coating.

[0057] In some embodiments, the first content of the lithium alloyable material in the first sublayer can be zero or close to zero.

[0058] In some embodiments, the first slurry comprises a solvent. In some embodiments, the solvent is nonaqueous and comprises at least one selected from the group consisting of N- methylpyrrolidone (NMP), 1,3 -di oxolane, 2,5,7, 10-tetraoxaundecane, and mixtures thereof. In some embodiments, the second slurry comprises a solvent which may be the same as or different from the one in the first slurry.

[0059] In some embodiments, the solvent in either slurry has a weight percentage ranging from 50% to 90% in the slurry.

[0060] In some embodiments, an anode protective layer is described as a component separate from an anode layer and disposed between an anode layer and a solid electrolyte layer. In some embodiments, an anode protective layer is described as part of an anode layer.

[0061] In some embodiments, the present disclosure provides a method for preparing an allsolid state battery (ASSB), the method comprising:1) having an anode layer comprising an anode current collector coated with a first coating adjacent to the anode current collector and a second coating on the first coating, each coating comprising a carbonaceous material, wherein the lithium alloyable material has a higher content in the second coating than that in the first coating, and2) laminating the anode layer with the anode protective layer, a solid electrolyte layer, and a cathode layer in the order, wherein the anode protective layer faces toward the solid electrolyte layer, thereby obtaining an ASSB comprising the anode layer, the solid electrolyte layer and the cathode layer.

[0062] In some embodiments, the anode layer, the solid electrolyte layer and the cathode layer are laminated via an isostatic pressing (IP) process. In some embodiments, the IP process is a warm isostatic pressing process.

[0063] In some embodiments, the IP process is conducted at a stacking pressure in a range from 100 MPa to 500 MPa.

[0064] In some embodiments, the IP process is conducted at a temperature in a range from 20 °C to 100 °C.

[0065] In some embodiments, the lithium alloyable material has a content of zero or close to zero in the first sublayer or coating.

[0066] In some embodiments, the anode protective layer exhibits a structure with a gradient concentration, wherein the particles of a lithium alloyable material with a decreasingconcentration gradient along a first direction along the thickness direction, wherein the first direction is defined as the direction oriented from the SE layer toward the anode layer.

[0067] In some embodiments, the anode protective layer with a gradient concentration of the lithium alloyable material is prepared by a dipping-coating method. In some embodiments, an anode current collector has one side protected and the other side subsequently dipped into a series of coating solutions (slurries) of the lithium alloyable material or its precursor with gradually increasing concentrations. Between two adjacent cycles, the majority of the solvent is removed before dipping into another coating solution. In some embodiments, the dippingcoating method includes facile solution dipping, sol-gel-based dip-coating, vacuum-assisted, spin-assisted, photo-assisted, and multi-layered dip-coating methods. In some embodiments, the carbonaceous material is separately deposited or coated. In some embodiments, a precursor of the carbonaceous material is deposited or coated. In some embodiments, the carbonaceous material or its precursor and the lithium alloyable material or its precursor are concurrently or sequentially coated.

[0068] In some embodiments, an anode layer with an anode protective layer, a solid electrolyte layer and a cathode layer are laminated or assembled under an isostatic pressing (IP) process. In some embodiments, the IP is conducted under a pressure in a range from 100 MPa to 500 MPa. In some embodiments, the IP is performed at a temperature in a range from 20 °C to 100 °C.

[0069] The disclosure will be better understood by reference to the Experimental Details which follow, but those skilled in the art will readily appreciate that the specific experiments detailed are only illustrative, and are not meant to limit the disclosure as described herein, as numerous variations and modifications of these exemplary embodiments are possible without undue experimentation. All such variations and modifications are within the scope of the teachings of this disclosure. It will be appreciated that the foregoing description and following examples, no matter how detailed they may appear in text, the disclosure may bepracticed in many ways, and the disclosure should be construed in accordance with the appended claims and equivalents thereof.EXAMPLE 1Preparation of anode protective layer and assembly of ASSB

[0070] Ag particles with a median particle size (D50) around 20-150 nm were mixed with carbon black, polyvinylidene fluoride (PVDF) binder and N-methylpyrrolidone (NMP) as solvent, resulting in a first slurry. The Ag weight content in the total solid weight was 20 wt%. The first slurry was coated on an SUS (stainless steel) foil with a thickness of 10 pm as anode current collector using a bar-coating method followed by drying in a convection oven. A second slurry was prepared using the same method as the first slurry except for the Ag weight content at 25 wt%. The second slurry was coated on the first coating layer directly and then dried overnight. The total thickness of the two coating layers on the anode current collector was 15 ~20 pm.

[0071] A cell comprising a cathode (85wt% CAM) with a cathode loading of around 6.8mAh / cm2, an anode as prepared above, and an SE layer was assembled and sealed in a pouch followed by an isostatic pressing, leading to a pouch cell of Example 1 (Ex. 1). The second layer coating was adjacent to the SE layer.

[0072] Example 2 (Ex. 2) and Example 3 (Ex. 3) were prepared in the same manner as in Example 1, except 10 wt% Ag and 0 wt% Ag were used in the first coating layer, respectively.

[0073] Four (4) comparative ASSBs were similarly prepared except using anode protective layers with different contents of Ag in the first and the second layers. The composition of comparative examples 1 to 4 and examples 1, 2 and 3 are summarized in Table 1. The Ag weight content in the second layer was lower than (or equal to) that of the first layer. The thickness of the anode protective layer in the comparative examples was the same as the one in Example 1.Assembly of cells and testing[00741 Cells comprising a cathode layer, an anode layer with an anode protective layer and a solid electrolyte layer were assembled and sealed in a pouch followed by an isostatic pressing.Table 1 Composition of first and second sublayers in the anode protective layer and resistance of cell

[0075] Fig. 4 shows an SEM image of a cross-section of Example 1 (Ex. 1), wherein the first sublayer (4-1) comprising 20wt% Ag is adjacent to the anode current collector (2-1) and the second sublayer (4-2) comprising 25wt% Ag, and the second sublayer (4-2) is disposed between the first sublayer (4-1) and an SE layer (not shown). Fig. 5 shows an SEM image of a cross-section of Example 2 (Ex. 2), wherein the first sublayer (4-1) comprising 10wt% Ag is adjacent to the anode current collector (2-1) and the second sublayer (4-2) comprising 25wt% Ag, and the second sublayer (4-2) is disposed between the first sublayer (4-1) and an SE layer (not shown). Fig. 6 shows an SEM image of a cross-section of Example 3 (Ex. 3), wherein the first sublayer (4-1) comprising 0wt% Ag is adjacent to the anode current collector (2-1) and the second sublayer (4-2) comprising 25wt% Ag, and the second sublayer (4-2) is disposed between the first sublayer (4-1) and an SE layer (not shown).

[0076] Rate testing of the cells was conducted under the same conditions with the charge rate at 0.1C and the discharge rate changing from 0.1C to 0.33C, 1C and then back to 0.1C sequentially.

[0077] The rate performance of comparative examples 1 to 4 and examples 1, 2 and 3 are shown in Figs. 7A through 7G and Table 2. Comparative examples 1 and 4 present relatively lower discharge capacities at higher C rates (0.33C and 1C) while the other comparative examples and examples exhibit a rate performance similar to each other.Table 2 Rate performance of examples and comparative examples

[0078] Cycling testing of the cells was conducted under 0.33C / 0.33C continuously at 45 °C with an external pressure in a range from 0.5MPa to 5.0MPa, wherein each cycle charges to 4.25 V and discharges to 2.5V.

[0079] Specific capacity, capacity retention rate and columbic efficiency (CE) during the first 100 cycles are shown in Figs. 8 A, 8B and 8C, respectively.

[0080] Comparative example 1 (Comp. Ex. 1), comparative example 2 (Comp. Ex. 2), comparative example 3 (Comp. Ex. 3), comparative example 4 (Comp. Ex. 4), example 1 (Ex.1), example 2 (Ex. 2) and example 3 exhibited a 1stdischarge specific capacity of 167.75 mAh / g, 172.25 mAh / g, 169.2 mAh / g, 165.27 mAh / g, 171.96 mAh / g, 170.41 mAh / g and 170.59 mAh / g at 0.33C, respectively.[00811 After 50 cycles at 45 °C and at 0.33C, the cell with example 1 as anode protective layer exhibited a capacity retention rate of 101.88%. It is higher than that of the cell with comparative examples 1 and 2 as anode protective layer with a capacity retention of 97.92% and 99.48%, respectively. After 100 cycles, the cell with example 1 as anode protective layer exhibited a capacity retention rate of 101.11%. It is higher than comparative examples 1 and 2 as anode protective layer with a capacity retention of 93.42% and 90.57%, respectively.

[0082] After 50 cycles at 45 °C and at 0.33C, the cell with example 2 as anode protective layer exhibited a capacity retention rate of 102.04%. It is higher than that of the cell with comparative examples 1 and 3 as anode protective layer with a capacity retention of 97.92% and 87.81%, respectively. After 100 cycles, the cell with example 2 as anode protective layer exhibited a capacity retention rate of 101.14%. It is higher than comparative examples 1 and 3 as anode protective layer with a capacity retention of 93.42% and 80.61%, respectively.

[0083] After 50 cycles at 45 °C and at 0.33C, the cell with example 3 as anode protective layer exhibited a capacity retention rate of 102.55%. It is higher than that of the cell with comparative examples 1 and 4 as anode protective layer with a capacity retention of 97.92% and 82.36%, respectively. After 100 cycles, the cell with example 2 as anode protective layer exhibited a capacity retention rate of 101.32%. It is higher than comparative example 1 as anode protective layer with a capacity retention of 93.42%. Comparative example 4 as anode protective layer degraded to a capacity retention of 79.86% after 59 cycles.

[0084] The result suggests that anode protective layer as disclosed herein can improve the capacity retention rate during cycling and elongate the cycle life.

[0085] The average CE of the first 50 cycles of the cell with example 1 as anode protection layer is 99.83%. It is slightly higher than the comparative examples 1 and 2 which have anaverage CE of 99.74% and 99.71%, respectively. The average CE of the first 100 cycles of the cell with example 1 as anode protection layer is 99.91%. It is slightly higher than the comparative examples 1 and 2 which have an average CE of 99.81% and 99.70%, respectively.

[0086] The average CE of the first 50 cycles of the cell with example 2 as anode protection layer is 99.82%. It is higher than the comparative examples 1 and 3 which have an average CE of 99.74% and 99.51%, respectively. The average CE of the first 100 cycles of the cell with example 2 as anode protection layer is 99.90%. It is higher than the comparative examples 1 and 3 which have an average CE of 99.81% and 99.66%, respectively. The result suggests that anode protective layer as disclosed herein can improve the average CE during cycling.Table 3 Cycling performance of examples and comparative examples

[0087] The average CE of the first 50 cycles of the cell with example 3 as anode protection layer is 99.81%. It is higher than the comparative examples 1 and 4 which have an average CE of 99.74% and 99.35%, respectively. The average CE of the first 100 cycles of the cell with example 2 as anode protection layer is 99.89%. It is higher than the comparative examples 1 which has an average CE of 99.81%. Comparative example 4 was stopped after 59 cycles dueto the low capacity retention. The result suggests that anode protective layer as disclosed herein can improve the average CE during cyclingAspects

[0088] In a first aspect of the present disclosure, an all-solid-state battery (ASSB) comprises• a solid electrolyte (SE) layer,• an anode layer; and• an anode protective layer between the anode layer and the SE layer, wherein the anode protective layer comprises:1) a first sublayer adjacent to the anode layer; and2) a second sublayer between the SE layer and the first sublayer, wherein each sublayer comprises a carbonaceous material and the second sublayer contains a lithium alloyable material with a content greater than that in the first sublayer.

[0089] In a second aspect according to the first aspect, the lithium alloyable material comprises at least one selected from the group consisting of Ag, Zn, Ti, Cd, Mg, Al, Ga, Si, Ge, In, Sn, Pb, Bi, and Sb.

[0090] In a third aspect according to the first or second aspect, the second sublayer contains the lithium alloyable material with a content in a range from 10wt% to 50wt%. In some embodiments, the first sublayer contains the lithium alloyable material with a content greater than zero and equal to or lower than 40wt%. In some embodiments, the carbonaceous material in each sublayer has a weight percentage of at least 50wt%.

[0091] In a fourth aspect according to any preceding aspect, the first sublayer is substantially free of the lithium alloyable material.

[0092] In a fifth aspect according to any preceding aspect, the lithium alloyable material in the anode protective layer exists in the form of particles. In some embodiments, the particles of thelithium alloyable material are distributed in a matrix of the carbonaceous material in either the second sublayer or both sublayers.

[0093] In a sixth aspect according to any preceding aspect, the lithium alloyable material in the anode protective layer exists in the form of particles with a median particle size (D50) in a range from 20 nm to 150 nm.

[0094] In a seventh aspect according to any preceding aspect, each sublayer independently has a thickness in a range from 1 pm to 50 pm. In some embodiments, the anode protective layer has a thickness in a range from 5 pm to 100 pm.

[0095] In an eighth aspect according to any preceding aspect, the AS SB exhibits a cycle life of at least 10% longer than that of an ASSB comprising an anode protective layer with the second sublayer containing the lithium alloyable material with a content equal to or lower than the first sublayer.

[0096] In a nineth aspect according to any preceding aspect, the ASSB exhibits at least one of the following: a) an initial specific capacity of at least 200 mAh / g at a rate of 0.1C at a temperature of 45 °C, b) a capacity retention of at least 98.00% after 50 cycles at a rate of 0.33C / 0.33C at a temperature of 45 °C, c) a specific capacity of at least 160 mAh / g after 50 cycles at a rate of 0.33C / 0.33C at a temperature of 45 °C, d) a capacity retention of at least 94.00% after 100 cycles at a rate of 0.33C / 0.33C at a temperature of 45 °C, e) a specific capacity of at least 150 mAh / g after 100 cycles at a rate of 0.33C / 0.33C at a temperature of 45 °C, f) an average CE of at least 99.75% for the first 50 cycles at a rate of 0.33C / 0.33C at a temperature of 45 °C, andg) an average CE of at least 99.85% for the first 100 cycles at a rate of 0.33C / 0.33C at a temperature of 45 °C,

[0097] In a tenth aspect according to any preceding aspect, the solid electrolyte layer comprises a sulfide material with a formula LixMlyM2zPi-pM3pS6-a-b-qOqClaBrb (Formula I), wherein 4<x<8, 0<y<l, 0<z <1, 0<p<l, 0<q<l, 0<a<2, 0<b<2, 0<6-a-b-q<6, 0<l-p<l, and wherein Ml is at least one element of Group 1 or Group 11 other than H or Li of the periodic table, M2 is at least one element of Group 2 of the periodic table, and M3 is at least one element of Group 14 of the periodic table.

[0098] In an eleventh aspect according to any preceding aspect, the anode layer comprises an anode current collector and optionally an anode active material layer on the anode current collector.

[0099] In some embodiments, the anode active material layer comprises at least one anode active material selected from the group consisting of lithium metal and lithium alloy.

[0100] In some embodiments, the anode current collector comprises at least one selected from the group consisting of Cu, stainless steel, Ti, Ni, Ta, Mo, Nb, Sn, Zn, Ag, Au, and alloy thereof.

[0101] In a twelfth aspect, the present disclosure provides a method for preparing an anode protective layer, comprising:1) coating a first slurry onto an anode current collector followed by a first drying, wherein the first slurry comprises a carbonaceous material and particles of a lithium alloyable material, leading to a first coating formed on the anode current collector, and2) coating a second slurry onto the first coating followed by a second drying, wherein the second slurry comprises a carbonaceous material and particles of the lithium alloyable material, thereby obtaining a second coating on the first coating of the anode current collector, wherein the lithium alloyable material in the second coating has a content higher than that in the first coating.[01021 In a thirteenth aspect, the present disclosure provides a method for preparing an allsolid state battery (ASSB), comprising:1) having an anode layer comprising an anode current collector and an anode protective layer, wherein the anode protective layer comprises a first coating adjacent to the anode current collector and a second coating on the first coating, each coating comprising a carbonaceous material, wherein the lithium alloyable material in the second coating has a content higher than that in the first coating, and2) laminating the anode layer with the anode protective layer, a solid electrolyte layer, and a cathode layer in the order, wherein the anode protective layer faces toward the solid electrolyte layer, thereby obtaining an ASSB comprising the anode layer, the solid electrolyte layer and the cathode layer, wherein the anode protective layer is disposed between the anode current collector and the solid electrolyte layer.

[0103] In a fourteenth aspect according to the thirteenth aspect, wherein the anode layer, the solid electrolyte layer and the cathode layer are laminated and pressurized via an isostatic pressing (IP) process.

[0104] In some embodiments, the IP process is conducted at a stacking pressure in a range from 100 MPa to 500 MPa.

[0105] In some embodiments, the IP process is conducted at a temperature in a range from 20 °C to 100 °C.

[0106] In a fifteenth aspect, the present disclosure provides an all-solid-state battery (ASSB) comprising:• a solid electrolyte (SE) layer,• an anode layer; and• an anode protective layer between the anode layer and the SE layer, wherein the anode protective layer comprises a carbonaceous material and a lithium alloyable material with a gradient concentration along the thickness direction of the anodeprotective layer, wherein the lithium alloyable material has a decreasing concentration along a first direction, wherein the first direction is defined as the direction that SE layer faces toward the anode layer.

[0107] While this specification contains many specific implementation details, these should not be construed as limitations on the scope of any invention or of what may be claimed, but rather as descriptions of features that may be specific to particular embodiments of particular inventions. Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.

[0108] All transitional phrases such as “comprising,” “including,” “carrying,” “having,” “containing,” “involving,” “holding,” “composed of,” and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases “consisting of’ and “consisting essentially of’ shall be closed or semi-closed transitional phrases, respectively.

[0109] Various embodiments of the features of this disclosure are described herein. However, it should be understood that such embodiments are provided merely by way of example, and numerous variations, changes, and substitutions can occur to those skilled in the art without departing from the scope of this disclosure. It should also be understood that various alternative to the specific embodiments described herein are also within the scope of this disclosure.

Claims

We claim:

1. An all-solid-state battery (ASSB) comprising:• a solid electrolyte (SE) layer,• an anode layer; and• an anode protective layer between the anode layer and the SE layer, wherein the anode protective layer comprises:1) a first sublayer adjacent to the anode layer; and2) a second sublayer between the SE layer and the first sublayer, wherein each sublayer comprises a carbonaceous material, the first sublayer comprises a lithium alloyable material, and the lithium alloyable material has a higher content in the second sublayer than that in the first sublayer.

2. The ASSB of claim 1, wherein the lithium alloyable material comprises at least one selected from the group consisting of Ag, Zn, Ti, Cd, Mg, Al, Ga, Si, Ge, In, Sn, Pb, Bi, and Sb.

3. The ASSB of claim 1 or 2, wherein the first sublayer contains the lithium alloyable material with a content greater than zero and equal to or lower than 40wt% and the second sublayer contains the lithium alloyable material with a content in a range from 10wt% to 50wt%.

4. The ASSB of claim 1 or 2, wherein the first sublayer is substantially free of the lithium alloyable material.

5. The AS SB of claim 1 or 2, wherein the lithium alloy able material in the anode protective layer exists in the form of particles, which are evenly distributed in the matrix of the carbonaceous material.

6. The AS SB of claim 1 or 2, wherein the lithium alloy able material in the anode protective layer exists in the form of particles with a median particle size (D50) in a range from 20 nm to 150 nm.

7. The AS SB of claim 1 or 2, wherein each sublayer independently has a thickness in a range from 1 pm to 50 pm.

8. The AS SB of claim 1 or 2, wherein the AS SB exhibits a cycling life of at least 10% longer than that of an ASSB comprising an anode protective layer with the second sublayer containing the lithium alloyable material with a content equal to or lower than the first sublayer.

9. The ASSB of claim 1 or 2, wherein the ASSB exhibits at least one of the following: a) an initial specific capacity of at least 200 mAh / g at a rate of 0.1C at a temperature of 45 °C, b) a capacity retention of at least 98.00% after 50 cycles at a rate of 0.33C / 0.33C at a temperature of 45 °C, c) a specific capacity of at least 160 mAh / g after 50 cycles at a rate of 0.33C / 0.33C at a temperature of 45 °C, d) a capacity retention of at least 94.00% after 100 cycles at a rate of 0.33C / 0.33C at a temperature of 45 °C,e) a specific capacity of at least 150 mAh / g after 100 cycles at a rate of 0.33C / 0.33C at a temperature of 45 °C, f) an average CE of at least 99.75% for the first 50 cycles at a rate of 0.33C / 0.33C at a temperature of 45 °C, and g) an average CE of at least 99.85% for the first 100 cycles at a rate of 0.33C / 0.33C at a temperature of 45 °C.

10. The ASSB of claim 1, wherein the solid electrolyte layer comprises a sulfide material with a formula LixMlyM2zPi-pM3pS6-a-b-qOqClaBrb (Formula I), wherein 4<x<8, 0<y<l, 0<z <1, 0<p<l, 0<q<l, 0<a<2, 0<b<2, 0<6-a-b-q<6, 0<l-p<l, and wherein Ml is at least one element of Group 1 or Group 11 other than H or Li of the periodic table, M2 is at least one element of Group 2 of the periodic table, and M3 is at least one element of Group 14 of the periodic table.

11. The ASSB of claim 1, wherein the anode layer comprises an anode current collector and optionally an anode active material layer on the anode current collector.

12. A method for preparing an anode protective layer, comprising:1) coating a first slurry onto an anode current collector followed by a first drying, wherein the first slurry comprises a carbonaceous material and particles of a lithium alloyable material, leading to a first coating with a first content on the anode current collector, and2) coating a second slurry onto the first coating followed by a second drying, wherein the second slurry comprises the carbonaceous material and particles of the first material,thereby obtaining a second coating with a second content on the first coating of the anode current collector, wherein the lithium alloyable material in the second coating has a content higher than that in the first coating.

13. A method for preparing an all-solid state battery (ASSB), comprising:1) having an anode layer comprising an anode current collector and an anode protective layer, wherein the anode protective layer comprises a first coating adjacent to the anode current collector and a second coating on the first coating, each coating comprising a carbonaceous material, wherein the lithium alloyable material in the second coating has a content higher than that in the first coating, and2) laminating the anode layer with the anode protective layer, a solid electrolyte layer, and a cathode layer in the order, wherein the anode protective layer faces toward the solid electrolyte layer, thereby obtaining an ASSB comprising the anode layer, the solid electrolyte layer and the cathode layer.

14. The method of claim 13, wherein the anode layer, the solid electrolyte layer and the cathode layer are laminated and pressurized via an isostatic pressing (IP) process before obtaining the ASSB.

15. An all-solid-state battery (ASSB) comprising:• a solid electrolyte (SE) layer,• an anode layer; and• an anode protective layer between the anode layer and the SE layer, wherein the anode protective layer comprises a carbonaceous material and a lithium alloyable material with a gradient concentration along the thickness direction of the anodeprotective layer, wherein the lithium alloyable material has a decreasing concentration along a first direction, wherein the first direction is defined as the direction that SE layer faces toward the anode layer.

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