Insulation gasket and solid-state batteries comprising same

Abstract

An insulation gasket surrounding a first electroactive material layer of a first electrode layer comprises a foldable extension, wherein the first electroactive material layer is on at least one side of a first current collector with a first electrode tab. Upon folding, the foldable extension of the insulation gasket turns into a folded extension and covers a layer of a second electrode, thus electrically insulating the first electrode tab from the second electrode layer. The first electrode may be cathode or anode. An electrochemical device comprising the insulation gasket is also disclosed. In some embodiments, an electrochemical device further comprises a second insulation gasket surrounding the periphery of a second electrode layer and comprising a second foldable extension, wherein, the second insulation gasket, upon folding, turns into a second folded extension covering a layer of the first electrode.

Description

INSULATION GASKET AND SOLID-STATE BATTERIES COMPRISING SAMECROSS-REFERENCE

[0001] The present application claims the benefit of US Serial No. 63 / 558,698, filed February 28, 2024, the entire content of which is incorporated herein by reference into this application.FIELD

[0002] This disclosure relates to an insulation gasket and electrochemical devices with the same. BACKGROUND

[0003] A solid electrolyte instead of liquid electrolyte is employed to improve flammability, safety and other properties of solid-state batteries. A layer of a solid electrolyte is sandwiched between a cathode layer and an anode layer, wherein the cathode layer comprises a cathode tab extending from a cathode current collector and an anode tab extending from an anode current collector. In general, an electrochemical device such as solid-state battery comprises multiples cathode tabs and anode tabs. A press during manufacturing such as warm isostatic pressing (WIP) is usually required to minimize the interfacial electrode / electrolyte resistance. On one hand, one of the electrode tabs, for example cathode tabs, may accidentally touch the other electrode due to the displacement during manufacturing, leading to short circuiting. On the other hand, the press may break or detach the electrode tabs due to the shear force around the edges of the solid electrolyte layer and / or electrode layer. Thus, there remains a need for a design that suppresses or avoids short circuiting and / or protects the integrity of the electrode tabs.SUMMARY

[0004] Disclosed is a cell assembly that includes an insulation gasket comprising a foldable extension and surrounding a layer of a first electrode comprising a first current collector with a first electrode tab, wherein the foldable extension, upon folding, turns into a folded extension covering a layer of second electrode, thus electrically insulating the first electrode tab from thelayer of the second electrode. An electrochemical device comprising the insulation gasket is also disclosed. In some embodiments, an electrochemical device further comprises a second insulation gasket surrounding the periphery of a layer of the second electrode and comprising a second foldable extension, wherein, the second insulation gasket, upon folding, turns into a second folded extension covering a layer of the first electrode.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 view of a cell assembly according to one embodiment of the present disclosure.

[0007] Fig. 2A shows a cross-section view of an insulation gasket according to one embodiment of the present disclosure. Fig. 2B shows a cross-section view of an insulation gasket according to another embodiment of the present disclosure. Fig. 2C shows a cross-section view of an insulation gasket according to one embodiment of the present disclosure.

[0008] Figs. 3A and 3B show a cell assembly within an insulation gasket prior to and after folding, respectively, according to some embodiments of the present disclosure.

[0009] Fig. 4 shows a view of an insulation gasket according to one embodiment of the present disclosure.

[0010] Fig. 5A shows a right view of an insulation gasket according to one embodiment of the present disclosure. Fig. 5B shows a cross-section view along A-A’ in Fig. 5A according to one embodiment of the present disclosure.

[0011] Fig. 6A shows a right view of an insulation gasket according to one embodiment of the present disclosure. Fig. 6B shows a cross-section view along B-B’ in Fig. 6A according to one embodiment of the present disclosure.

[0012] Fig. 7A shows a right view of an insulation gasket according to one embodiment of the present disclosure. Fig. 7B shows a cross-section view along C-C’ in Fig. 7A according to one embodiment of the present disclosure.

[0013] Fig. 8A shows a right view of an insulation gasket according to one embodiment of the present disclosure. Fig. 8B shows a cross-section view along Cl -Cl’ in Fig. 8A according to one embodiment of the present disclosure.

[0014] Fig. 9A shows a right view of an insulation gasket according to one embodiment of the present disclosure. Fig. 9B shows a cross-section view along C2-C2’ in Fig. 9A according to one embodiment of the present disclosure.

[0015] Fig. 10A shows a right view of an insulation gasket according to one embodiment of the present disclosure. Fig. 10B shows a cross-section view along C3-C3’ in Fig. 10A according to one embodiment of the present disclosure.

[0016] Fig. 11A shows a right view of an insulation gasket according to one embodiment of the present disclosure. Fig. 11B shows a cross-section view along D-D’ in Fig. 11 A according to one embodiment of the present disclosure.

[0017] Fig. 12A shows a right view of an insulation gasket according to one embodiment of the present disclosure. Fig. 12B shows a cross-section view along E-E’ in Fig. 12A according to one embodiment of the present disclosure.

[0018] Fig. 13A shows a right view of an insulation gasket according to one embodiment of the present disclosure. Fig. 13B shows a cross-section view along F-F’ in Fig. 13A according to one embodiment of the present disclosure.

[0019] Fig. 14A shows a right view of an insulation gasket according to one embodiment of the present disclosure. Fig. 14B shows a cross-section view along G-G’ in Fig. 14A according to one embodiment of the present disclosure.

[0020] Figs. 15A-15F show representative connections between the gasket ring and the foldable extension according to some embodiments of the present disclosure.

[0021] Fig. 16 shows a view of an insulation gasket after folding electrode tabs according to one embodiment of the present disclosure.

[0022] Fig. 17 shows a view of an insulation gasket according to one embodiment of the present disclosure.

[0023] Fig. 18 shows a view of an insulation gasket after folding electrode tabs according to one embodiment of the present disclosure.DETAILED DESCRIPTION

[0024] Disclosed is a cell assembly that reduces the potential for short circuiting by separating and insulating cathode tabs from anodes and / or separating and insulating anode tabs from cathodes. This is accomplished by having a cell assembly with an insulation gasket comprising a foldable extension and surrounding the periphery of a layer of a first electrode comprising a first current collector with a first electrode tab, wherein the foldable extension, upon folding, turns into a folded extension covering at least a part of the periphery of a layer of second electrode, thus electrically insulating the first electrode tab from the layer of the second electrode. An electrochemical device comprising the insulation gasket is also disclosed. In some embodiments, the cell assembly and electrochemical device further comprises a second insulation gasket surrounding the periphery ofa layer of the second electrode and comprising a second foldable extension, wherein, the second insulation gasket, upon folding, turns into a second folded extension covering at least a part of the periphery of a layer of the first electrode.

[0025] Fig. 1 is a view of a cell assembly without showing insulation gaskets according to one embodiment of the present disclosure. The cell assembly comprises a first electrode layer (10), a solid electrolyte layer (20), and a second electrode layer (30). In some embodiments, the first electrode layer (10) comprises a first electroactive material layer (11) on at least one side of a first current collector (12) with a first electrode tab (1201) protruding or extending therefrom. In some embodiments, the first electrode is either cathode or anode. In some embodiments, the second electrode layer (30) comprises a second electrode tab (3201) protruding or extending from a second current collector (32). In some embodiments, the second electrode layer (30) further comprises a second electroactive material layer (not shown in Fig. 1).

[0026] In some embodiments, the present disclosure provides an insulation gasket surrounding the periphery of the first electroactive material layer (11). In some embodiments and as shown in Figs. 2A-3C, an insulation gasket (50) comprises one or more foldable extensions. As shown in Fig. 2A, an insulation gasket (50) comprises a gasket ring (500) and a foldable extension (501) on the right side. As shown in Fig. 2B, an insulation gasket (50) comprises a gasket ring (500) and a foldable extension (501) on the left side. In some embodiments and as shown in Fig. 2C, an insulation gasket (50) comprises a gasket ring (500), a first foldable extension (501) on one side and a second foldable extension (502) on the opposing side. In some embodiments, the first and second foldable extensions (501 and 502) may be located at the same or different side. In some embodiments, the gasket ring (500) has a shape complementary to the periphery of the first electroactive material layer (11), which can be a circular, rectangular or triangular shape or any regular or non-regular shape.

[0027] In some embodiments and as shown in Fig. 3A, the cell assembly may comprise one or more insulation gaskets (50), wherein each insulation gasket (50) surrounds a first electroactive material layer (11).

[0028] As illustrated in Fig. 3B, the first electrode tab (1201) is sandwiched between a pair of insulation gaskets, i.e., a first insulation gasket (50_a) underneath the first electrode tab (1201) and a second insulation gasket (50_b) above the first electrode tab (1201). After folding, their foldable extensions turn into a folded underneath extension (501 l a) and a folded upper extension (501 l b), respectively. The folded underneath extension (501 l a) covers the edge of the solid electrolyte layer (20) and the second electrode layer (30), thus physically separating and electrically insulating the first electrode tab (1201) from the second electrode layer (30). It suppresses and / or avoids short-circuiting therebetween. On the other hand, both the folded underneath extension (501 l a) and the folded upper extension (5011 b) protect the first electrode tab (1201) from any external damage or mechanical failure due to cutting force, compression and / or displacement around the edge, for example when folding the first electrode tab (1201). In some embodiments, the first insulation gasket (50_a) and the second insulation gasket (50_b) have the same or different shape. In some embodiments, the first insulation gasket (50_a) has a shape complementary to the second insulation gasket (50_b).

[0029] In some embodiments, the cell assembly further comprises a second electroactive material layer on the second current collector and a second set of insulation gasket surrounding the periphery of the second electroactive material layer. In some embodiments, the insulation gasket surrounding the first electroactive material layer and placed next to the first electrode tab, is referred to as a first set of insulation gaskets. In some embodiments, the first set of insulation gaskets may comprise one insulation gasket on either side or each side of the first electrode tab. In some embodiments, the insulation gasket surrounding the second electroactive material layer andplaced next to the second electrode tab, is referred to as a second set of insulation gaskets. In some embodiments, the second set of insulation gaskets may comprise one insulation gasket on either side or each side of the second electrode tab.

[0030] In some embodiments, the foldable extension (501) of an insulation gasket (50) has a length (1) and a width (w) as shown in Fig. 4. In some embodiments, the foldable extension (501) has a length (1) smaller than that of the first electrode tab (1201). In some embodiments, the foldable extension (501) has a width equal to or greater than that of the first electrode tab (1201).

[0031] In some embodiments, the foldable extension (501) of the insulation gasket (50) has a height (h) (alternatively thickness) equal to or less than the gasket ring (500). As shown in Fig. 5A and 5B, the foldable extension (501) has a height equal to the gasket ring (500). As shown in Figs. 6A and 6B, the foldable extension (501) has a height (h) from about 40% to 60% of the gasket ring (500).

[0032] In some embodiments, the foldable extension (501) has a length in a range from 1 pm to 3000 pm. In some embodiments, foldable extension (501) has a length in a range from 10 pm to 3000 pm, from 20 pm to 3000 pm, from 50 pm to 3000 pm, from 100 pm to 3000 pm, from 200 pm to 3000 pm, from 300 pm to 3000 pm, or from 500 pm to 3000 pm. In some embodiments, foldable extension (501) has a length in a range from 20 pm to 2500 pm, from 50 pm to 2500 pm, from 100 pm to 2500 pm, from 200 pm to 2500 pm, from 300 pm to 2500 pm, from 350 pm to 2500 pm, from 400 pm to 2500 pm, or from 450 pm to 2500 pm. In some embodiments, foldable extension (501) has a length in a range from 25 pm to 2000 pm, from 50 pm to 2000 pm, from 100 pm to 2000 pm, from 200 pm to 2000 pm, from 300 pm to 2000 pm, from 350 pm to 2000 pm, from 400 pm to 2000 pm, or from 500 pm to 2000 pm. In some embodiments, foldable extension (501) has a length in a range from 25 pm to 1500 pm, from 50 pm to 1500 pm, from100 gm to 1500 gm, from 200 gm to 1500 gm, from 300 gm to 1500 gm, from 400 gm to 1500 gm, or from 500 gm to 1500 gm.

[0033] In some embodiments, the foldable extension (501) has a width in a range from 0.1 mm to 50 mm. In some embodiments, foldable extension (501) has a width in a range from 0.1 mm to 40 mm, from 0.5 mm to 40 mm, from 1.0 mm to 40 mm, from 2.0 mm to 40 mm, from 5.0 mm to 40 mm, from 7.5 mm to 40 mm, or from 10 mm to 40 mm. In some embodiments, the foldable extension (501) has a width in a range from 0.1 mm to 30 mm, from 0.5 mm to 30 mm, from 1.0 mm to 30 mm, from 4.0 mm to 30 mm, from 5.0 mm to 30 mm, from 7.5 mm to 30 mm, or from 10 mm to 30 mm. In some embodiments, the foldable extension (501) has a width in a range from 0.1 mm to 20 mm, from 0.5 mm to 20 mm, from 1.0 mm to 20 mm, from 4.0 mm to 20 mm, from 5.0 mm to 20 mm, from 7.5 mm to 20 mm, or from 10 mm to 20 mm.

[0034] In some embodiments, the thickness ratio of the foldable extension (501) to the gasket ring (500) is in a range from 25% to 100%, from 25% to 80%, from 25 % to 60%, from 25% to 40%, from 40% to 100%, from 40% to 80%, from 40 % to 60%, or any and all subranges and ranges therebetween.

[0035] In some embodiments, the gasket ring (500) has a thickness equal to or greater than the first electroactive material layer (11). In some embodiments, the thickness ratio of the gasket ring (500) to the first electroactive layer (11) is in a range from 100 % to 110%, from 100 % to 120%, from 100 % to 130%, from 100 % to 150%, from 105 % to 110%, from 105 % to 120%, from 105 % to 130%, from 105 % to 150%, from 110 % to 120%, from 110 % to 130%, from 110 % to 150%, from 120 % to 130%, from 120 % to 150%, or any and all subranges and ranges therebetween.

[0036] In some embodiments, the first electroactive material layer (11) has a thickness in a range from 1 gm to 1000 gm, from 1 gm to 850 gm, from 1 gm to 500 gm, from 1 gm to 300 gm, from 1 gm to 250 gm, from 5 gm to 1000 gm, from 10 gm to 1000 gm, from 50gm to 1000 gm, from75 pm to 1000 pm, from 100 pm to 1000 pm, from 200 pm to 1000 pm, from 10 pm to 800 pm, from 15 urn to 650 pm, from 20 pm to 500 pm, from 25pm to 300 pm, from 75 pm to 300 pm, from 100 pm to 300 pm, or any and all subranges and ranges therebetween.

[0037] In some embodiments, the foldable extension (501) comprises an engineered surface (504). As typically shown in Figs. 7A, 7B, 8A and 8B, the engineered surface (504) is an arc surface. In some embodiments, the foldable extension (501) has a non-fixed height. In some embodiments, the height of the foldable extension is expressed as an average height along the total length of the foldable extension (501). In some embodiments, the foldable extension (501) has a minimum height (hmm) at the end as shown in Fig. 7B. In some embodiments, the minimum height is zero.

[0038] In some embodiments, the engineered surface (504) can be an arc surface such as those in Figs. 7B and 8B. In some embodiments, the engineered surface (504) can be a slope or inclined plane, such as Figs. 9A, 9B, 10A, and 10B. In some embodiments, the engineered surface can also be a laddering surface or any combination thereof.

[0039] In some embodiments, the insulation gasket (50) comprises a channel to accommodate the first electrode tab (1201). As exemplarily shown in Figs. 11 A and 1 IB, the insulation gasket (50) comprises a channel (505) which accommodates the first electrode tab (1201). In some embodiments, the channel (505) is an indentation along the surface of the extension or an opening at the gasket ring (500) and / or the extension (501) When a stack of electrode layer and electrolyte layer is laminated and assembled, the channel (505) may reduce the shear force around the edge and thus suppress the damage to the first electrode tab (1201) or detach from the first electrode current collector which is not shown in Figs. 11A and 11B. In some embodiments, the channel (505) has a width less than that of the foldable extension (501). In some embodiments, the channel (505) has a width equal to or greater than that of the first electrode tab (1201).

[0040] In some embodiments, the insulation gasket (50) comprises an engineered surface (504) (such as an arc surface or slope or inclined plane) and a channel (505) along the surface as shown in Figs.12A and 12B. When the channel (505) is part of the insulation gasket (50), the engineered surface (504) may comprise two sub-surfaces, i.e., one along the original engineered surface (5041) and the other one having a lowered height (5042) as shown in Figs. 12A and 12B. In some embodiments, when the first electrode tab (1201) is folded, it will fit into the channel (505). On the one hand, the engineered surface (504) guides the folding path and behavior of the first electrode tab (1201). On the other hand, the engineered surface (504) and the channel (505) dissipate or reduce the cutting forces along the edge during compression-decompression cycles, thus protecting the first electrode tab (1201) from detaching from the first current collector (12).

[0041] In some embodiments, the channel (505) may extend from the top surface via an engineered surface, and all the way to the side surface of the foldable extension (501) as shown in Figs. 13A and 13B.

[0042] In some embodiments and as shown in Figs. 14A and 14B, the insulation gasket (50) comprises an engineered surface (504) and a channel (505). The engineered surface (504) is further divided into a first subsurface (5041) and a second subsurface (5042), wherein the second subsurface (5042) has a lowered height in comparison to the first subsurface (5041). The arc surface as shown in Figs. 14A and 14B may guide the folding of the first electrode tab (1201) in a controlled manner and protect it by avoiding stress concentration that may happen at a sharp edge or corner.

[0043] In some embodiments, the foldable extension (501) is connected or coupled with the gasket ring (500) via a notched neck to facilitate the folding or arrangement of the foldable extension (501). Representative notched necks (506) are shown in Figs 15A-15F. In some embodiments, the notched neck (506) comprises a designed indentation on one side of the foldable extension(501) as representatively shown in Figs. 15A, 15B, 15E and 15F. In some embodiments, the notched neck (506) comprises an indentation on two sides as representatively shown in Figs. 15C and 15D. In some embodiments, the notched neck (505) is a rectangular (e.g., Fig. 15A), circular or U-shaped (e.g., Fig. 15B), trapezoidal (e g., Fig. 15E), or V-shaped (e.g., Fig. 15F) indentation on one side of the extension, particularly near the portion next to the gasket ring (500). In some embodiments, the notched neck (506) is a rectangular (e.g., Fig.l5C), triangular, circular or U- shaped (e.g. Fig. 15D), or V-shaped indentation on two opposite or adjacent sides at a portion of the extension (501) next to the gasket ring (500). In some embodiments, the notched neck (506) is a cylinder whose cross-section is smaller than that of the protrusion. In some embodiments, the notched neck (506) is a circular indentation on both sides at a portion of the foldable extension (501). In some embodiments, the notched neck (506) is formed during preparation of the insulation gasket (50) such as molding. In some embodiments, the notched neck (506) is formed by cutting or etching the foldable extension (501).

[0044] As shown in Fig. 16, an electrochemical device comprises a pair of insulation gaskets, i.e., a first insulation gasket (50_a) underneath the first electrode tab (1201) and a second insulation gasket (50_b) above the first electrode tab (1201). After folding, their foldable extensions turn into a folded underneath extension (501 l a) and a folded upper extension (501 l_b), respectively. The first insulation gasket (50_a) comprises a second folded extension (502 l a) while the second insulation gasket (50_b) also comprises a second folded extension (5021_b).

[0045] In some embodiments, a first current collector (12) may or may not have an extra edge area not covered by the first electroactive material layer (11). As shown in Figs. 3A, 3B and 15, the first current collector (12) exhibits a surface area higher than that of the first electroactive material layer (11) and comprises an extra edge area not covered by the first electroactive material layer (11) on the left side of the drawings.

[0046] In some embodiments and as shown in Fig. 17, the left side of the first electrode current collector (12) has a length substantially the same as the first electroactive material (11), i.e., there is no extra edge area. In some embodiments and as shown in Fig. 18, particularly two dotted cycles, it can be seen that a simple stack of two adjacent insulation gaskets would insulate the left side of the first electrode layer (10) from the second electrode tab (3201) without forming any folded extension.

[0047] In some embodiments, after folding, the insulation gasket (50) has a first folded extension (5011) on one side of the first electroactive layer while the other side does not have any folded extension. In some embodiments, the absence of the folded extension on the other side is either because the insulation gasket does not have a second foldable extension or because the insulation gasket does include a second foldable extension, which, however, does not turn into a folded extension due to the supporting effect from the adjacent insulation gasket.

[0048] In some embodiments, the solid electrolyte layer comprises at least one selected from the group consisting of P2S5, Li2S — P2S5 — LiX (where X is a halogen element), Li2S — P2S5 — Li2O, Li2S— P2S5— Li2O— Lil, Li2S— SiS2, Li2S— SiS2— Lil, Li2S— SiS2— LiBr, Li2S— SiS2— LiCl, Li2S— SiS2— B2S3— Lil, Li2S— SiS2— P2S5— Lil, Li2S— B2S3, Li2S— P2S5— ZmSn (where m and n are each a positive number, and Z is one selected from Ge, Zn and Ga), Li2S — GeS2, Li2S — Si S2— Li3PO4, Li2S — SiS2— LiPMOq(where p and q are each a positive number, and M is one selected from P, Si, Ge, B, Al, Ga, and In), Li7-xPS6-xClx(0<x<2), Li7-xPS6-xBrx(0<x<2), and Li7-xPS6-xIx (0<X<2).

[0049] In some embodiments, the first electrode layer comprises a first electroactive material layer on at least one side of a first current collector. In some embodiments, the first electroactive material layer is a cathode active material layer. In some embodiments, the cathode active material layer comprises at least one selected from the group consisting of LiFePCh, LixM02, LixNii-y-zCoyMlzO2and LixNii-y-zMnyM2zO2, wherein M is at least one selected from the group consisting of Ni, Co, Mn, Al, B, Fe, Mg, Ca, Sr, Sc, Y, Ti, Zr, V, Nb, Ta, Cr, Mo, W, Rh, Pd, Cu, Zn, Cd, Ga, In, Sn, and rare earth elements, wherein Ml is at least one selected from the group consisting of Mn, Al, B, Fe, Mg, Ca, Sr, Sc, Y, Ti, Zr, V, Nb, Ta, Cr, Mo, W, Rh, Pd, Cu, Zn, Cd, Ga, In, Sn, and rare earth elements, wherein M2 is at least one selected from the group consisting of Co, Al, B, Fe, Mg, Ca, Sr, Sc, Y, Ti, Zr, V, Nb, Ta, Cr, Mo, W, Rh, Pd, Cu, Zn, Cd, Ga, In, Sn, and rare earth elements, and wherein 0.95 < x < 1.1, l-y-z>0, 0< y < 0.5, 0 < z < 0.5.

[0050] In some embodiments, the first current collector comprises at least one selected from the group consisting of Al, stainless steel, Cu, Ni, Ti, carbonaceous materials, Ta, Mo, Nb, Sn, Zn, Ag, Au, Cu-Ni alloy, Cu-Zn alloy, Ni-Cr alloy, phosphor bronze and an alloy thereof. In some embodiments, the first current collector has a structure selected from the group consisting of foil, mesh and foam. In some embodiments, the first current collector and the second current collector are made of the same or different materials.

[0051] In some embodiments, the second electrode layer comprises a second current collector. In some embodiments, the second 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. In some embodiments, the collector foil is made of a material selected from Cu-Ni alloy, Cu-Zn alloy, Ni- Cr alloy and phosphor bronze.

[0052] In some embodiments, the second electrode layer comprises a second current collector without a second electroactive material layer before the first charge / discharge cycle. In some embodiments, after the first charge / discharge cycle, a second electrode layer that initially comprises a second current collector without a second electroactive material layer may comprise a second electroactive material layer on at least one side of the second current collector. In someembodiments, a second electrode layer comprises a second electroactive material layer on at least one side of the second current collector prior to the first charge / discharge cycle.

[0053] In some embodiments, the second electroactive material comprises lithium metal or lithium alloy. In some embodiments, a lithium alloy is an alloy of lithium metal with at least one element selected from the group consisting of C, Si, Sn, Ge, B, Al, In, Bi, Sb, Na, Mg, Zn, Au, and Ag.

[0054] In some embodiments, the cell assemblies disclosed herein may be incorporated into an electrochemical device, for example an all-solid-state battery.

[0055] In some embodiments, the present disclosure provides a method for preparing a cell assembly. The method may include: a) positioning a first electrode layer with a first electrode tab extended therefrom, the first electrode layer comprising a first electroactive material layer on at least one side of a first electrode current collector; b) positioning an insulation gasket comprising a foldable extension so that the insulation gasket surrounds a periphery of the first electroactive material layer, c) stacking a solid electrolyte layer and a second electrode layer having a second electrode tab extended therefrom over the first electrode, wherein the solid electrolyte layer is sandwiched between the first and second electrode layers, d) folding the first electrode tab, which turns the foldable extension of the insulation gasket into a folded extension covering the second electrode layer, leading to a pre-assembly with the folded extension, and, e) placing the pre-assembly with the folded extension into a pouch followed by sealing, thereby obtaining a cell assembly wherein the first electrode tab is electrically insulated from the second electrode layer.

[0056] In some embodiments, the folding of the electrode tabs and the foldable extensions of the insulation gasket may be accomplished using a tool or mold to apply pressure to fold the tabs. In some embodiments, isostatic pressure may be used. In some embodiments, the pressure may be in a range from 200 MPa to 1,000 MPa, 300 MPa to 1,000 MPa, 400 MPa to 1,000 MPa, 500 MP to 1,000 MPa, or any and all ranges and subranges there between. The pressure may be applied for a sufficient amount or period of time for example in a range from 1 minute to 120 minutes, 5 minutes to 120 minutes, 10 minutes to 120 minutes, 30 minutes to 120 minutes, 45 minutes to 120 minutes, 60 minutes to 120 minutes, or any and all ranges and subranges therebetween. The pressure may also be applied at an elevated temperature, for example in a range from 40°C to 100°C, 50°C to 100°C, 60°C to 100°C, 70°C to 100°C, or any and all ranges and subranges therebetween.

[0057] In some embodiments, the cell assembly may be sealed in a pouch. In some embodiments, the pouch may be incorporated into an electrochemical device. In some embodiments, the cell assemblies are tested for presence of a short circuit by measuring the open circuit voltage (OCV) across the electrode tabs. The cell assemblies as provided in the present disclosure exhibit reduced short circuits.Aspects

[0058] In a first aspect of the present disclosure, a cell assembly comprises: a) a first electrode layer comprising a first current collector, a first electroactive material layer on the first current collector and a first electrode tab protruding from the first current collector; b) a second electrode layer comprising a second current collector and a second electrode tab protruding from the second current collector; c) a solid electrolyte layer between the first electrode layer and the second electrode layer; andd) an insulation gasket surrounding a periphery of the first electroactive material layer, wherein the insulation gasket comprises a folded extension that covers the second electrode layer, thus electrically insulating the first electrode tab from the second electrode layer.

[0059] In a second aspect according to the first aspect of the present disclosure, the second electrode layer further comprises a second electroactive material layer on the second current collector. In some embodiments, the folded extension has a height equal to or greater than the thickness of the second electrode layer being surrounded. In some embodiments, the folded extension has a length shorter than the first electrode tab. In some embodiments, the folded extension has a width equal to or greater than the first electrode tab.

[0060] In a third aspect according to any preceding aspect, the insulation gasket is compressible. In some embodiments, the insulation gasket exhibits a compressibility greater than that of the first or second electrode, or both.

[0061] In a fourth aspect according to any preceding aspect, the insulation gasket comprises at least one insulating polymer selected from the group consisting of polypropylene (PP), polyethylene (PE), polyimide, styrene-butadiene rubber (SBR), sulfonated tetrafluoroethylene based fluoropolymer-copolymer, polytetrafluoroethylene (PTFE), poly vinyl alcohol (PVA), polyvinylidene fluoride (PVDF), a polyvinylidene fluoride copolymer, polyethylene oxide (PEO), epoxy resin, silicone resin, silicone rubber, polyurethane, melamine resin, urea resin, alkyd resin, and copolymer thereof.

[0062] In a fifth aspect according to any preceding aspect, the insulation gasket is placed on one side of the first electrode tab and a second insulation gasket is placed on the other side of the first electrode tab.

[0063] In a sixth aspect according to the fifth aspect, after folding, the first electrode tab comprises a first portion along the direction of first current collector and a bent portion intersecting with thefirst portion, a folded extension of the second insulation gasket covers at least partially the bent portion of the first electrode tab, so that the first and second insulation gaskets protect the first electrode tab from damage.

[0064] In a seventh aspect according to any preceding aspect, the insulation gasket comprises multiple folded extensions, which are folded toward the same or different directions.

[0065] In an eighth aspect according to any preceding aspect, the insulation gasket further comprises a channel for accommodating the first electrode tab, which is electrically connected to a first lead tab located outside the insulation gasket.

[0066] In a nineth aspect according to any preceding aspect, the cell assembly further comprises a second electroactive material layer on the second current collector and a second set of insulation gasket surrounding the periphery of the second electroactive material layer. In some embodiments, the insulation gasket, either one or two, surrounding the first electroactive material layer and placed next to the first electrode tab, is referred to as a first set of insulation gaskets. In some embodiments, the insulation gasket, either one or two, surrounding the second electroactive material layer and placed next to the second electrode tab, is referred to as a second set of insulation gaskets.

[0067] In some embodiments, the second set of insulation gasket is made of a material the same as or different from the insulation gasket. In some embodiments, the first electrode layer is a cathode layer or an anode layer. In some embodiments, the cathode layer comprises at least one selected from the group consisting of LiFePC , LixMCh, LixNii-y-zCoyMlzCh and LixNii-y-zMnyM2zO2, wherein M is at least one selected from the group consisting of Ni, Co, Mn, Al, B, Fe, Mg, Ca, Sr, Sc, Y, Ti, Zr, V, Nb, Ta, Cr, Mo, W, Rh, Pd, Cu, Zn, Cd, Ga, In, Sn, and rare earth elements, wherein Ml is at least one selected from the group consisting of Mn, Al, B, Fe, Mg, Ca, Sr, Sc, Y, Ti, Zr, V, Nb, Ta, Cr, Mo, W, Rh, Pd, Cu, Zn, Cd, Ga, In, Sn, and rare earth elements, wherein M2 is at least one selected from the group consisting of Co, Al, B, Fe, Mg, Ca, Sr, Sc, Y,Ti, Zr, V, Nb, Ta, Cr, Mo, W, Rh, Pd, Cu, Zn, Cd, Ga, In, Sn, and rare earth elements, and wherein 0.95 < x < 1.1, l-y-z>0, 0< y < 0.5, 0 < z < 0.5.

[0068] In a tenth aspect according to any preceding aspect, the first current collector is a cathode current collector, the first electrode tab is a cathode tab, and the first current collector and the first electrode tab independently comprise at least one selected from the group consisting of Al, stainless steel, Cu, Ti, Ni, Ta, Mo, Nb, Sn, Zn, Ag, Au, Cu-Ni alloy, Cu-Zn alloy, Ni-Cr alloy, phosphor bronze and alloys thereof.

[0069] In an eleventh aspect according to any preceding aspect, the second current collector is an anode current collector, the second electrode tab is an anode tab, and the anode current collector and the anode tab independently comprise at least one selected from the group consisting of Cu, stainless steel, Ti, Ni, Ta, Mo, Nb, Sn, Zn, Ag, Au, Cu-Ni alloy, Cu-Zn alloy, Ni-Cr alloy, phosphor bronze and alloys thereof. In some embodiments, an all-solid-state battery comprises a cell assembly described herein.

[0070] In a twelfth aspect, the present disclosure provides a method for preparing a cell assembly comprises: a) positioning a first electrode layer with a first electrode tab extended therefrom, the first electrode layer comprising a first electroactive material layer on at least one side of a first electrode current collector; b) positioning an insulation gasket comprising a foldable extension so that the insulation gasket surrounds a periphery of the first electroactive material layer, c) stacking a solid electrolyte layer and a second electrode layer having a second electrode tab extended therefrom over the first electrode, wherein the solid electrolyte layer is sandwiched between the first and second electrode layers,d) folding the first electrode tab, which turns the foldable extension of the insulation gasket into a folded extension covering the second electrode layer, leading to a pre-assembly with the folded extension, and, e) placing the pre-assembly with the folded extension into a pouch followed by sealing, thereby obtaining a cell assembly wherein the first electrode tab is electrically insulated from the second electrode layer.

[0071] In a thirteenth aspect according to the twelfth aspect, prior to the sealing, a compression is applied to the pouch at a temperature for a period of time.

[0072] In a fourteenth aspect according to the thirteenth aspect, the compression is an isostatic compression.

[0073] In a fifteenth aspect according to the thirteenth aspect, the temperature is in a range from 40 to 100 °C, the period of time is in a range from 1 to 120 min, and the compression is in a range from 200 to 1000 MPa. In some embodiments, the step b) is conducted either before or after the step c) or concurrently with step c).

[0074] It is to be noted that the transitional term “comprising”, which is synonymous with “including”, “containing” or “characterized by”, is inclusive or open-ended and does not exclude additional, un-recited elements or method steps.

[0075] 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 alternatives to the specific embodiments described herein are also within the scope of this disclosure.

Claims

We claim:

1. A cell assembly comprising: a) a first electrode layer comprising a first current collector, a first electroactive material layer on the first current collector and a first electrode tab protruding from the first current collector; b) a second electrode layer comprising a second current collector and a second electrode tab protruding from the second current collector; c) a solid electrolyte layer between the first electrode layer and the second electrode layer; and d) an insulation gasket surrounding a periphery of the first electroactive material layer, wherein the insulation gasket comprises a folded extension that covers the second electrode layer, thus electrically insulating the first electrode tab from the second electrode layer.

2. The cell assembly of claim 1, wherein the second electrode layer further comprises a second electroactive material layer on the second current collector.

3. The cell assembly of any preceding claim, wherein the insulation gasket is compressible.

4. The cell assembly of any preceding claim, wherein the insulation gasket comprises at least one insulating polymer selected from the group consisting of polypropylene (PP), polyethylene (PE), polyimide, styrene-butadiene rubber (SBR), sulfonated tetrafluoroethylene based fluoropolymer-copolymer, polytetrafluoroethylene (PTFE), poly vinyl alcohol (PVA), polyvinylidene fluoride (PVDF), a polyvinylidene fluoride copolymer, polyethylene oxide (PEO), epoxy resin, silicone resin, silicone rubber, polyurethane, melamine resin, urea resin, alkyd resin, and copolymers thereof.

5. The cell assembly of any preceding claim, further comprising a second insulation gasket peripherally surrounding the first electroactive material layer, wherein the insulation gasket is placed on one side of the first electrode tab and the second insulation gasket is placed on the other side of the first electrode tab.

6. The cell assembly of claim 5, wherein, after folding, the first electrode tab comprises a first portion along the direction of first current collector and a bent portion intersecting with the first portion, a folded extension of the second insulation gasket covers at least partially the bent portion of the first electrode tab, so that the first and second insulation gaskets protect the first electrode tab from damage.

7. The cell assembly of any preceding claim, wherein the insulation gasket comprises multiple folded extensions, which are folded toward the same or different directions.

8. The cell assembly of any preceding claim, wherein the insulation gasket further comprises a channel for accommodating the first electrode tab, which is electrically connected to a first lead tab located outside the insulation gasket.

9. The cell assembly of any preceding claim, further comprising a second electroactive material layer on the second current collector and a second set of insulation gasket surrounding the periphery of the second electroactive material layer.

10. The cell assembly of any preceding claim, wherein the first current collector is a cathode current collector, the first electrode tab is a cathode tab, and the first current collector and the first electrode tab independently comprise at least one selected from the group consisting ofAl, stainless steel, Cu, Ti, Ni, Ta, Mo, Nb, Sn, Zn, Ag, Au, Cu-Ni alloy, Cu-Zn alloy, Ni-Cr alloy, phosphor bronze and alloys thereof.

11. The cell assembly of any preceding claim, wherein the second current collector is an anode current collector, the second electrode tab is an anode tab, and the anode current collector and the anode tab independently comprise at least one selected from the group consisting of Cu, stainless steel, Ti, Ni, Ta, Mo, Nb, Sn, Zn, Ag, Au, Cu-Ni alloy, Cu-Zn alloy, Ni-Cr alloy, phosphor bronze and alloys thereof.

12. A method for preparing a cell assembly comprising: a) positioning a first electrode layer with a first electrode tab extended therefrom, the first electrode layer comprising a first electroactive material layer on at least one side of a first electrode current collector; b) positioning an insulation gasket comprising a foldable extension so that the insulation gasket surrounds a periphery of the first electroactive material layer, c) stacking a solid electrolyte layer and a second electrode layer having a second electrode tab extended therefrom over the first electrode, wherein the solid electrolyte layer is sandwiched between the first and second electrode layers, d) folding the first electrode tab, which turns the foldable extension of the insulation gasket into a folded extension covering the second electrode layer, leading to a preassembly with the folded extension, and, e) placing the pre-assembly with the folded extension into a pouch followed by sealing, thereby obtaining a cell assembly wherein the first electrode tab is electrically insulated from the second electrode layer.

13. The method of claim 12, wherein, prior to the sealing, a compression is applied to the pouch at a temperature for a period of time.

14. The method of claim 13, wherein the compression is an isostatic compression.

15. The method of claim 13, wherein the temperature is in a range from 40 to 100 °C, the period of time is in a range from 1 to 120 min, and the compression is in a range from 200 to 1000 MPa.

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