Patent Publication Number: US-2023133563-A1

Title: Protected electrode structures for solid-state cells

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is related to and claims priority under 35 U.S.C. § 119 from U.S. Provisional Pat. Application No. 63/263,370, filed Nov. 1, 2021, entitled “Protected Electrode Structures for Solid-State Cells,” the entire contents of which are fully incorporated by reference herein for all purposes. 
    
    
     TECHNICAL FIELD 
     Various embodiments described herein relate to the field of solid-state primary and secondary electrochemical cells, electrodes and electrode materials, electrolyte compositions, and corresponding methods of making and using these electrochemical cells. 
     BACKGROUND AND INTRODUCTION 
     With the ever-increasing adoption of mobile devices, electric automobiles, and the development of Internet-of Things devices, the need for battery technologies with improved reliability, capacity (Ah), thermal characteristics, lifetime, and recharge performance has never been greater. Solid-state battery cells utilize nonflammable, solid electrolyte in contrast to the flammable, liquid electrolyte used in traditional batteries. Thus, the solid-state battery cells are safer than traditional batteries. However, in some solid-state battery cells, the movement of lithium ions or electrons is hindered because the solid-state interface has increased resistance as compared to traditional batteries with liquid electrolyte. 
     As an example of the increased resistance of the solid-state interface, International Patent Publication No. WO2012/077197(A1) describes a solid-state battery cell where the various stacked layers that include a positive electrode collector—positive electrode active material layer—solid electrolyte layer—negative electrode active material layer—negative electrode collector are combined by applying pressure to them to form a stack, or in another embodiment, pressing a positive electrode collector—positive electrode active material layer— solid electrolyte layer—negative electrode active material layer—negative electrode collector to form a stack. When this stacking method is employed, significant problems arise within the solid-state battery cell, such as shorting of the cell, increasing cell resistance, and lowering specific cell capacity. The problems within this solid-state battery cell may be due to the solid-state interface between the layers being of poor quality. 
     Thus, further improvements are needed in solid-state-battery cells, their chemistry, and their manufacture. It is with these observations in mind, among other, that aspects of the present disclosure were conceived. 
     SUMMARY 
     This disclosure describes an encapsulated electrode for an electrochemical cell comprising an electrode layer and a solid-state electrolyte composite wherein the solid-state electrolyte composite is in contact with the electrode layer and encapsulates the electrode layer. 
     In one embodiment, the encapsulated electrode for an electrochemical cell comprises one or more of an electrode active material. In another embodiment of the encapsulated electrode for an electrochemical cell, two or more sides of the electrode layer are encapsulated by the sold-state electrolyte composite. 
     In another embodiment, the encapsulated electrode for an electrochemical cell comprises one or more of an anode active material or one or more of a cathode active material. In another embodiment, the encapsulated electrode for an electrochemical cell comprises one or more of an alkali metal, an alkaline earth metal, a transition metal or an alloy thereof. In another embodiment, the encapsulated electrode for an electrochemical cell comprises lithium metal or a lithium metal alloy. 
     In another embodiment of the encapsulated electrode for an electrochemical cell, the electrode layer comprises one or more electrode layers. In another embodiment of the encapsulated electrode for a solid-state electrochemical cell, the solid-electrolyte composite comprises one or more solid-state electrolyte materials. 
     In another embodiment of the encapsulated electrode for a solid-state electrochemical cell, the solid-state electrolyte composite comprises one or more polymers in an amount of between 0.5% and 80% by weight of the solid-state electrolyte composite. In another embodiment of the encapsulated electrode for a solid-state electrochemical cell, the solid-state electrolyte composite comprises one or more polymers comprising at least one of a thermoplastic elastomer. In one embodiment, the one or more polymers comprise fluorine. 
     In another embodiment of the encapsulated electrode for a solid-state electrochemical cell, the electrode layer comprises one or more of a solid-state sulfide electrolyte. 
     In another embodiment, the encapsulated electrode for an electrochemical cell comprises an engineered surface coating comprising one of more of a lithium element, a carbon element, and an oxygen element. In one embodiment, the engineered surface coating has a thickness of 1 nm to 100 µm. 
     In another embodiment, the encapsulated electrode for an electrochemical cell comprises an encapsulated anode or an encapsulated cathode. 
     This disclosure also describes a method for manufacturing an encapsulated electrode for a solid-state electrochemical cell comprising providing an electrode to be encapsulated, positioning the electrode to be encapsulated between two layers of solid-state electrolyte composite, and compressing the two layers of solid-state electrolyte composite to contact and encapsulate the electrode. 
     In another embodiment of the method, the compressing includes applying pressure in the range of 100 to 400,000 PSI thereby causing the solid-state electrolyte composite to densify and deform to cover one or more surfaces of the electrode to be encapsulated. 
     The present disclosure also describes an encapsulated electrode for an electrochemical cell comprising an electrode layer with a first face, a second face, and a peripheral surface; a first layer of solid-state electrolyte composite in contact with and extending beyond a boundary of the first face of the electrode layer; a second layer of solid-state electrolyte composite in contact with and extending beyond a boundary of the second face of the electrode layer, wherein portions of the first layer and second layer of solid-state electrolyte composite that extend beyond boundaries of the first face and second face of the electrode layer are in contact and fully encapsulate the electrode, and wherein portions of the solid-state electrolyte composite extending beyond boundaries of the first face and second face of the electrode layer have a lower density than that of portions of the solid-state electrolyte composite within boundaries of the first and second faces. 
     In one embodiment of the encapsulated electrode, the electrode layer comprises one or more of an electrode active material comprising lithium metal or lithium alloy. In another embodiment of the encapsulated electrode, the electrode layer comprises an anode capable of conducting alkali metal ions. 
     In one embodiment of the encapsulated electrode, the electrode layer comprises a current collector comprising stainless steel or copper foils. 
     In one embodiment of the encapsulated electrode, the anode comprises an engineered coating. 
     The present disclosure provides a solid-state battery cells with improved solid-state interfaces between the positive electrode layer—solid electrolyte layer and between the negative electrode layer—solid electrolyte layer. Additionally, the present application discloses a novel cell architecture, which enhances cycle life, specific cell capacity, and lower cell resistance. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure may be understood by reference to the following detailed description taken in conjunction with the drawings briefly described below. It is noted that, for purposes of illustrative clarity, certain elements in the drawings may not be drawn to scale. 
         FIG.  1 A  shows the proposed arrangement of one embodiment of the encapsulated electrode structure  105  before assembly. 
         FIG.  1 B  shows the proposed arrangement of one embodiment of the encapsulated electrode structure  105  after the three layers are assembled wherein the outer boundary of the first SSE  170  and the outer boundary of the second SSE  180  are both longer than the electrode  130  and are not attached to the electrode. 
         FIG.  1 C  illustrates the proposed arrangement of one embodiment of the encapsulated electrode structure  105  after the three layers are assembled and pressure is applied to the arrangement. 
         FIG.  1 D  shows the encapsulated electrode structure  105  after the continued application of pressure is applied to the arrangement, so that the SSE  110  and SSE  120  come in contact to form a unified SSE  125 , which encloses or encapsulates the electrode  135 . 
         FIG.  2    is a flow chart for a process for forming an encapsulated electrode structure. 
         FIG.  3 A  illustrates the proposed processing of one embodiment of the encapsulated electrode structure  310  and the shearing device  320  appropriately positioned. 
         FIG.  3 B  shows the proposed processing of one embodiment of the encapsulated electrode structure  310  just after shearing is initiated by the shearing device  320 . 
         FIG.  3 C  illustrates the proposed processing of one embodiment of the encapsulated electrode structure  310  after shearing device  320  shears the solid electrolyte composite along the edges of the encapsulated electrode  310  forming encapsulated electrode structure  330  and removing the remaining SSE  331 . 
         FIG.  4    is a flow chart for a process for partitioning an encapsulated electrode structure. 
         FIG.  5 A  shows the 3-dimensional structure of one embodiment of the electrode  500 . 
         FIG.  5 B  shows the 3-dimensional structure of one embodiment of the solid electrolyte composite layer  540 . 
         FIG.  5 C  shows the 3-dimensional arrangement of one embodiment of the encapsulated electrode structure  580  before the three layers are assembled. 
         FIG.  5 D  shows a 3-dimensional representation of encapsulated electrode structure  590  after the continued application of pressure is applied to the layered arrangement. 
         FIG.  6 A  is a side view of a calendaring device and process of forming a protected electrode. 
         FIG.  6 B  is a top view of an SSE/electrode/SSE stack of  FIG.  6 A . 
         FIG.  6 C  is a section view of the SSE/electrode/SSE stack of  FIG.  6 A  taken along line C-C. 
         FIG.  6 D  is a side section view of the SSE/electrode/SSE stack of  FIG.  6 A  at  618 . 
         FIG.  6 E  is a side view of the SSE/electrode/SSE stack undergoing densification by way of calendar rollers. 
         FIG.  7 A  is a first set of SEM images of a first example of a protected electrode. 
         FIG.  7 B  is a second set of SEM images of a second example of a protected electrode. 
         FIG.  7 C  is a third set of SEM images of a third example of a protected electrode. 
     
    
    
     DETAILED DESCRIPTION 
     Aspects of the present disclosure involve an encapsulated electrode structure and methods of manufacturing the same. Aspects disclosed herein may provide for a technique whereby densification of the electrode structure may be enhanced and more uniform resulting in beneficial improvements in the performance of the electrode, and battery within which the electrode is included. Aspects of the disclosure may provide for the ability to better work with soft electrode materials such as electrodes including Lithium layers. For example, by encapsulating the relatively softer electrode in relatively harder electrolyte material prior to densification, the relatively softer electrode material is captured by the surrounding electrolyte blocking extrusion of the electrode material under possibly high densification pressures. These and other advantages of various aspects of the present disclosure are described in more detail below. 
     In the following description, specific details are provided to impart a thorough understanding of the various embodiments of the technology. Moreover, to avoid obscuring the technology, some well-known methods, processes, devices, and systems finding application in the various embodiments described herein are not disclosed in detail. 
     The term “battery” in the art and herein can be used in various ways and may refer to an individual cell having an anode and cathode separated by an electrolyte, which may be a solid electrolyte, as well as a collection of such cells connected in various arrangements. A solid-state electrolyte cell may include more than one anode and cathode, separated by solid electrolyte layers, and may be ultimately encased within a flexible “pouch” that accommodates the expansion and contraction of the anode and cathode as the cell charges and discharges. Although many examples are discussed herein as applicable to a battery or a discrete cell, it should be appreciated that the systems and methods described may apply to many different types of batteries, battery chemistries, and may range from an individual cell to batteries involving different possible interconnections of cells such as cells coupled in parallel, series, and parallel and series. The various implementations discussed herein may also apply to different structural battery arrangements including pouch cells and other cell structures that may accommodate size changes in the electrodes, whether the anode or the cathode or both. 
       FIGS.  1 A- 1 D  are a set of pictorial representations of process steps for forming encapsulated electrode structure  105  that are associated with process  200  of  FIG.  2   . The representations illustrated in  FIGS.  1 A- 1 D  are representative section views.  FIG.  1 A  shows the proposed arrangement of one embodiment of the encapsulated electrode structure  105  before assembly of the three layers that will form the encapsulated electrode. One layer of the encapsulated electrode structure  105  is a first solid-state electrolyte composite (SSE)  110  that has a top surface  140 , a bottom surface  145 , and a peripheral surface  142 . The SSE layer may also be referred to as a separator layer. The peripheral surface is the surface defining an edge between the upper and lower surface. Reference to top and bottom here is from the perspective of the structure illustrated in the figures, and is done for the convenience of the reader. It is possible that a manufacturing technique might present the layers in other arrangements such that the top might be considered the bottom, the bottom considered the top, and the like. Another layer of the encapsulated electrode structure is the electrode  130  that has a top (first) surface  160 , a bottom (second) surface  165 , and a peripheral surface  162 . Yet another layer of the encapsulated electrode structure  105  is a second SSE  120  that has a top surface  155 , a bottom surface  150 , and a peripheral surface  152 . The first SSE  110  is arranged so as to be operably coupled with the electrode  130 , wherein the bottom surface of the first SSE  145  is to be operably coupled with the top surface of the electrode  160 . The bottom surface of the electrode  165  is to be operably coupled with the top surface of the second SSE  155 . 
     In some embodiments, the length of the each of the SSE  110  and SSE  120  can be the same or different and can range from 5 millimeters to 1 meter. In another embodiment, the range of lengths is 1 cm to 500 cm. In yet another embodiment, the range of lengths is 2 cm to 100 cm. In a further embodiment, the range of lengths is 2 cm to 50 cm. In another embodiment, the range of lengths is 3 cm to 30 cm. In some embodiments, the length of the each of the SSE  110  and SSE  120  can be the same length of the electrode or longer length than that of the electrode  130 . In another embodiment, one of the SSE  110  or  120  can be slightly shorter than the length of the electrode  130  and the other SSE  110  or  120  can be longer than the length of the electrode  130 . 
     In some embodiments, the widths of the each of the SSE  110  and SSE  120  can be 5 millimeters to 1 meter. In another embodiment, the widths of the each of the SSE  110  and SSE  120  can be 1 cm to 500 cm. In yet another embodiment, the widths of the each of the SSE  110  and SSE  120  can be 2 cm to 100 cm. In a further embodiment, the widths of the each of the SSE  110  and SSE  120  can be 2 cm to 50 cm. In another embodiment, the widths of the each of the SSE  110  and SSE  120  can be 3 cm to 30 cm. In some embodiments, the widths of the each of the SSE  110  and SSE  120  can be the same as the width of the electrode or of greater width than that of the electrode  130 . 
     In some embodiments, the height of the each of the SSE  110  and SSE  120  can be 1 micron to 1 mm. In another embodiment, the height of the each of the SSE  110  and SSE  120  can be 5 microns to 500 microns. In yet another embodiment, the height of the each of the SSE  110  and SSE  120  can be 10 microns to 250 microns. In a further embodiment, the height of the each of the SSE  110  and SSE  120  can be 15 microns to 200 microns. In another embodiment, the height of the each of the SSE  110  and SSE  120  can be 20 microns to 100 microns. In some embodiments, the height of the each of the SSE  110  and SSE  120  can be the same as the height of the electrode or of longer height than that of the electrode  130 . 
       FIG.  1 B  shows the proposed arrangement of one embodiment of the encapsulated electrode structure  105  after the three layers (SSE  110 , electrode  130  and SSE 120 ) are assembled wherein the outer boundary of the first SSE  170  and the outer boundary of the second SSE  180  exceed the length of the electrode  130  and as such are not attached to the electrode. In an alternative embodiment, at least one of the first SSE  170  and the second SSE  180  is the same length as the electrode and the other of the first SSE  170  and the second SSE  180  is substantially longer than the electrode  130 . 
     While various techniques for lamination and densification are possible, in one example, the layers of the protected electrode are run through a calendar press. In one example, producing an encapsulated electrode comprises a stack of a center electrode layer, solid-state electrolyte (SSE) layers, and carrier film layers (such as an aluminum foil layer), which is removed prior to use in a cell. The aluminum carrier layers are not illustrated in  FIGS.  1 A- 1 D . In one implementation, the center electrode layer may be lithium foil and the layers may be arranged initially in an Aluminum-SSE-Lithium-SSE-Aluminum stack. The SSE layer may comprise a sulfide-based solid electrolyte material and binder cast onto the aluminum foil. To laminate and otherwise operably couple the lithium foil layer to the SSE layers, the stack may be fed through a calendar press device comprising a first roller and a second roller. The rollers exert a compressive force on the stack to laminate the layers together while also reducing the porosity of the materials within the stack (densifying), enhancing material contact within and between the layers, causing some layers to adhere or otherwise laminate, and/or also causing some layers to partially or completely separate (e.g., the outer aluminum foil layers). The pressure applied to the stack by the calendar press may correlate to a spacing between the first roller and the second roller. 
       FIG.  6 A  is a diagram illustrating manufacturing a solid-state protected electrode laminate  602  using a calendar press device  604 , according to aspects of the present disclosure. In one implementation, the protected solid-state electrode laminate  602  may include two separator layers of a composite blend of a solid-state electrolyte (SSE) and a binder. The SSE  606  may be coated as a thin layer on a carrier film  608 . In one example, the carrier film  608  may be an aluminum foil, although other materials may be used. A thin foil of lithium metal  610  may be placed between two facing SSE layers  606 . To generate a protected electrode (e.g., anode) stack, two different sheets of the SSE  606  on foil  608  may be oriented such that the SSE layers are facing each other with the lithium metal layer  610  between the two SSE sheets. Other combinations of layers and compositions of layers may be used for other types of stacks, such as a cathode stack. In this implementation, the layers forming the electrode stack  602  are fed between the calendar rollers  614 ,  616  in an Aluminum-SSE-Lithium-SSE-Aluminum stack. When assembled into a cell, the protected anode is comprised of the SSE-Lithium-SSE stack where the aluminum foil has been removed. The composite SSE layers  606  in this configuration may conduct ions, but not electrons, during use in a battery cell such that the SSE layers provide electrical isolation for the middle lithium anode material of layer  610 . The respective rollers of the calendar press  604  are spaced apart a distance less than the pre-calendared stack thickness such that pressure on the stack being fed between the calendar rollers  614 ,  616  may reduce the porosity of the materials within the stack, enhance material contact, cause some layers to adhere or bond, and/or cause the SSE layers  606  to partially or completely separate from the aluminum foil  608  while laminating to the lithium foil  610  layer. It should be recognized that in some instances, the calendar press does not delaminate the outer foil layer and a subsequent delamination operation may be used. In other instances, the calendaring process weakens the SSE adhesion to the outer foil making subsequent removal more efficient. The pressure exerted by the calendar rollers  614 ,  616  on the stack may be adjusted through a calendar controller  612  configured to adjust the space between the calendar rollers. Upon removal of the aluminum foil  608  from the stack, an SSE-Li-SSE stack is produced that may then be used as an anode in an electrochemical cell. Other stacks may include the same or different types of layers or compositions of layers for use in an electrochemical cell. 
       FIG.  6 B  is a top view of the various sheets forming the protected electrode stack noting that the electrode, e.g., lithium layer, is inset (e.g., lesser width) from the outer edges of the SSE sheets. A first  626 A and a second  626 B region of the upper and lower SSE layers are laminated and densified between the calendar rollers, and forming protective boundaries to a portion of the electrode layer  610 A between the regions  626 A/ 626 B.  FIG.  6 C  is a section view at C-C of the stack prior to calendaring and  FIG.  6 D  is a side section of the protected electrode stack after calendaring at point  618  emphasizing the inner electrode layer is inset from the respective edges of the SSE layers. From the perspective of  FIG.  6 B  it can be seen that the side edges of the electrode layer are inset from the side edges of the respective SSE layers. 
       FIG.  6 E  is a close up view of the calendaring rollers  614  and  666 , and showing how a stack SSE  606 / electrode  610 / SSE  606  is laminated/densified using the rollers. The view in  FIG.  6 E  does not illustrate the aluminum foil  608  layers.  FIG.  6 E  further illustrates a way of generating a progessing protective boundary to the electrode  610 . As the sheets are fed between the calendar press, the previously densified portion (or the portion undergoing densification) at  620  of the electrode layer is immediately adjacent a portion  622  of the electrode layer between the rollers and undergoing densification. The previously densified stack thus forms a protective boundary at the leading edge of the portion of the electrode undergoing densification thus providing a third boundary  620 , in addition to those at the sides of the sheet where the width of the upper and lower SSE layers exceeds the width of the electrode layers, enhancing densification as the stack proceeds between the rollers. It should be noted that electrode layer in some instances is not densified due to the characteristics of the material. For example, in the case of a Lithium electrode layer, the SSE layers are densified but the metal Lithium layer does not densify. The Lithium layer may, however, extrude or flow, as noted herein, under densification pressures. Conversely, for example, non-metal anode electrode layers, such as Silicon composite, graphite composite, or the like, or cathode layers, such as NMC composite, Pyrite composite, Sulfur composite, or the like, do densify. 
       FIG.  1 C  illustrates the proposed arrangement of one embodiment of the encapsulated electrode structure  105  after the three layers (SSE  110 , electrode  130  and SSE 120 ) are laminated and pressure is applied to the arrangement. As pressure is applied, the SSE  110  and SSE  120  start to become compacted and densified to form SSE  112  and SSE  122 , which form around the electrode  132 , which may have also become compacted and densified. As noted elsewhere, some electrode materials such as Lithium do not densify whereas other electrode materials, e.g., non-metals, do densify. In a calendaring operation with cylindrical rollers, the initial compaction and densification shown in  FIG.  1 C  occurs as the stack is first fed between the rollers and the final compaction and densification shown in  FIG.  1 D  occurs at the area of highest densification pressure where the separation between the upper and lower rollers is least. 
       FIG.  1 D  shows the encapsulated electrode structure  105  after the continued application of pressure is applied to the arrangement, so that the SSE  110  and SSE  120  have come in contact with each other to form a unified SSE  125 , which encloses electrode  135 . Referring again to  FIG.  6 D , it can be seen that a unified SSE  624  is formed around along the sides  632  of the electrode  610 , after the stack proceeds through the densification step at the rollers in the example of using a calendar press. 
     An encapsulated electrode structure may refer to an electrode or electrode layer  130  that is enclosed in a solid electrolyte material SSE or one or more solid electrolyte layers SSE, such that the first (e.g., upper) and second (e.g., lower) surfaces of the electrode are laminated to the respective adjacent SSE layers and the lateral sides of the electrode or electrode layer are in contact with the solid electrolyte materials of the upper and lower layers that is pressed together to encapsulate the electrode edges inset from the respective area where the upper and lower SSE layers contact each other during densification. The electrode may be exposed at least one edge side of the assembled stack as will be discussed in more detail below. 
     In some embodiments, an encapsulated electrode structure may refer to an electrode or electrode layer that is enclosed in a solid electrolyte material along at least two edges or sides when referring to a rectangular shaped electrode. When encapsulated, the electrode layer is between solid state electrolyte layers such that all faces and at least one side of the electrode or electrode layer are in contact with a solid electrolyte material or one or more solid electrolyte layers. In another embodiment, the encapsulated electrode structure may refer to an electrode or electrode layer that is enclosed in a solid electrolyte material or one or more solid electrolyte layers such that all faces and at least two sides of the electrode or electrode layer are in contact with a solid electrolyte material or one or more solid electrolyte layers. In yet another embodiment, the encapsulated electrode structure may refer to an electrode or electrode layer that is enclosed in a solid electrolyte material or one or more solid electrolyte layers such that all faces and at least three sides of the electrode or electrode layer are in contact with a solid electrolyte material or one or more solid electrolyte layers. In yet a further embodiment, the encapsulated electrode structure may refer to an electrode or electrode layer that is enclosed in a solid electrolyte material or one or more solid electrolyte layers such that all faces and all but two sides of the electrode or electrode layer are in contact with a solid electrolyte material or one or more solid electrolyte layers. The side or sides of the electrode not enclosed by solid electrolyte may provide an electrical contact to the electrode for forming the electrode into a battery. 
     Referring again to  FIG.  1 B , after densification and the foil removed, the protected electrode, e.g., anode, may be formed by trimming the SSE-Li-SSE stack of sheets into discrete sections. The dotted lines set out in  FIG.  1 B  illustrate where such trimming may occur. As can be seen, the upper and lower edges (faces) of the electrode are encapsulated by the SSE layers whereas the leading and trailing edges (faces) of the electrode are exposed after trimming. As can be seen in  FIG.  1 D , the upper and lower surfaces of the electrode are also encapsulated by the respective upper and lower SSE layers. 
     When forming an encapsulated anode, electrode  130  may be free standing with a thickness in the range of 1 µm to 1 mm. A free standing anode is one that does not have an “attached” or separate current collector. In examples discussed herein, when the anode is made of Lithium or an alloy of lithium, the Lithium is the active material powering the cell and the current collector. 
     An example of not free standing is when the active material is placed on a current collector such as Lithium deposited onto a copper foil. In some embodiments, the thickness of the anode is in the range of 2 µm to 750 µm. In another embodiment, the thickness of the anode is in the range of 3 µm to 500 µm. In another embodiment, the thickness of the anode is in the range of 4 µm to 250 µm. In another embodiment, the thickness of the anode is in the range of 5 µm to 150 µm. In another embodiment, the thickness of the anode is in the range of 5 µm to 100 µm. In another embodiment, the thickness of the anode is in the range of 5 µm to 75 µm. In another embodiment, the thickness of the anode is in the range of 5 µm to 50 µm. In another embodiment, the thickness of the anode is in the range of 5 µm to 45 µm. In yet another embodiment, the thickness of the anode is in the range of 5 µm to 35 µm. In another embodiment, the thickness of the anode is in the range of 1 µm to 15 µm. 
     In some embodiments of the encapsulated anode, electrode  130 , may contain multiple layers of one or more materials. In some embodiments, 2 to 10 layers may be used. In another embodiment, 2 to 5 layers may be used. 
     In a further embodiment, the encapsulated anode may be or include a current collector such as but not limited to stainless steel and copper foils. In one embodiment, the encapsulated electrode comprises 3-10 current collectors. The encapsulated anode may be one or more anode active materials in contact with one or more sides of a current collector, with examples of the active materials being Silicon containing materials (Si, SiO 2 , Si-Lithium alloys, Si—Na alloys), Carbon containing materials (Graphite, graphene, carbon black, etc.), Aluminum, Magnesium, Tin, Germanium, and Titanium containing such as LTO (Li 4 Ti 5 O 12 ). 
     In some applications it may be necessary for one or more materials contained in the encapsulated anode to have an engineered coating on one or more of its faces. In some embodiments, one or more of the anode active materials has an engineered coating. In another embodiment, one or more of the current collectors has an engineered coating. In yet another embodiment, the engineered coating may be one or more of a carbon-based material for example but not limited to graphite, graphene, carbon nanotubes, and carbon black. In a further embodiment, the carbon-based coating may be a composite containing one or more of a material capable of alloying with an alkali metal for example but not limited to Au, Ag, Zn, Zr, In, Ge, Si, Sn, or Al. In another embodiment, the engineered coating may be one or more of an oxygen-containing-species for example but not limited to Li 2 CO 3 , Li 2 O, Li 2 SO 4 , Na 2 CO 3 , Al 2 O 3 , ZrO 2 , or SiO 2 . In yet another embodiment, the engineered coating may be one or more of a sulfide-containing-species for example but not limited to Elemental Sulfur, CuS, CuSO 4 , NiS, NiSO 4 , or FeS 2 . In a further embodiment, the engineered coating may be one or more nitrogen-containing-species for example but not limited to LiNO 3 , Li 3 N, Li 2 NH, LiNH 2 , LiCN, NaNO 3 , Ag NO 3 , or Cu(NO 3 ) 2 . In a further embodiment, the engineered coating may be one or more halogen-containing-species for example but not limited to LiF, LiCl, LiBr, NaF, KF, Li 0.5 Na 0.5 F, Li 0.5 Na 0.5 Cl, Na 0.5 K 0.5 F, Na 0.5 K 0.5 Cl, MgF 2 , CaF 2 , or AgF. In yet another embodiment the engineered coating may be one or more phosphorous-containing-species for example but not limited to Li 3 PO 4 , P 2 S 5 , or P 2 O 5 . In another embodiment, the engineered coating may be one or more polymers for example but not limited to a polymer comprising styrene, butadiene, one or more halogens, sulfur, or nitrogen. 
     In the engineered coating of the encapsulated anode, electrode  130  may have a thickness that ranges from 1 nm to 100 µm. In some embodiments, the thickness ranges from 50 µm to 75 µm. In another embodiment, the thickness ranges from 1 µm to 50 µm. 
     Similar to the formation of an encapsulated anode, in the formation of an encapsulated cathode, a suitable electrode and appropriate solid-state electrolyte composite  110  and  120  may be prepared. As with the single or multiple layers that may be used as electrode  130  when an encapsulated anode is formed, a multilayer structure may be used when an encapsulated cathode is formed. For example, a multilayer structure such as one or more cathode active materials in contact with one or more sides of a current collector may be used as electrode  130 . To encapsulate this multilayer electrode structure, solid-electrolyte composite  110  and  120  may be applied as would be done for an anode electrode. In this multilayer structure the cathode active material may be a NMC material (material containing Nickel, Manganese and Cobalt), for example but not limited to, NMC 111 (LiNi 0.33 Mn 0.33 Co 0.33 O 2 ), NMC 433 (LiNi 0.4 Mn 0.3 Co 0.3 O 2 ), NMC 532 (LiNi 0.5 Mn 0.3 Co 0.2 O 2 ), NMC 622 (LiNi 0.6 Mn 0.2 Co 0.2 O 2 ), or NMC 811 (LiNi 0.8 Mn 0.1 Co 0.1 O 2 ). In another embodiment, the cathode active material may be a different element-substituted Li—Mn spinels for example but not limited to, Li—Mn—Ni—O, Li—Mn—Al—O, Li—Mn—Mg—O, Li—Mn—Co—O, Li—Mn—Fe—O or Li—Mn—Zn—O. In another embodiment, the cathode active material may be a lithium metal phosphate for example but not limited to LiFePO 4 , LiMnPO 4 , LiCoPO 4  or LiNiPO 4 . In another embodiment, the cathode active material may be one or more of a LiCoO 2  or NCA (material containing Nickel, Cobalt, Aluminum) (e.g., LiNi 0.8 Co 0.15 Al 0.05 O 2 ). In another embodiment, the cathode active material may be one or more of a conversion cathode such as S, Li 2 S, TiS 2 , MoS 2 , VS 2 , CrS 2 , FeS 2 , FeF 2 , FeF 3 , CuF 2 , or MnO. Furthermore, in this multilayer structure the current collector may be aluminum, stainless steel, copper, or nickel. 
     When forming an encapsulated cathode, the thickness of the cathode may be in the range of 1 µm to 1000 µm. In some embodiments, the thickness of the cathode is in the range of 3 µm to 900 µm. In another embodiment, the thickness of the cathode is in the range of 5 µm to 800 µm. In another embodiment, the thickness of the cathode is in the range of 10 µm to 700 µm. In another embodiment, the thickness of the cathode is in the range of 12.5 µm to 600 µm. In another embodiment, the thickness of the cathode is in the range of 15 µm to 500 µm. In another embodiment, the thickness of the cathode is in the range of 17.5 µm to 400 µm. In another embodiment, the thickness of the cathode is in the range of 20 µm to 300 µm. In another embodiment, the thickness of the cathode is in the range of 22.5 µm to 200 µm. In yet another embodiment, the thickness of the cathode is in the range of 25 µm to 100 µm. In another embodiment, the thickness of the cathode is in the range of 25 µm to 75 µm. 
     Solid-state electrolyte composite  110  and  120  may include a sulfide solid-state electrolyte and one or more binders, which may be in the form of polymers where solid-state electrolyte composites  110  and  120  may be 0% to 80% polymer by weight of the composite. In another embodiment, the polymer can be 1% to 70% by weight of the composite. In another embodiment, the polymer can be 3% to 60% by weight of the composite. In another embodiment, the polymer can be 4% to 50% by weight of the composite. In another embodiment, the polymer can be 5% to 40% by weight of the composite. In another embodiment, the polymer can be 10% to 30% by weight of the composite. 
     The polymer in the solid-state electrolyte composite  110  and  120  may be one or more of a fluorine-containing polymer for example but not limited to polytetrafluoroethylene (PTFE), polyvinylene difluoride (PVdF), poly (vinylene difluoride-hexafluoropropylene) copolymer (PVdF-HFP), and the like. In another embodiment, a thermoplastic-elastomer may be used, for example but not limited to, styrene-butadiene rubber (SBR), styrene butadiene styrene copolymer (SBS), styrene isoprene copolymer (SIS), polyacrylonitrile (PAN), nitrile-butylene rubber (NBR), polybutadiene, polyisoprene, Poly (methacrylate) nitrile-butadiene rubber (PMMA-NBR) and the like. In another embodiment, an acrylic resin may be used, for example but not limited to, polymethyl (meth) acrylate, polyethyl (meth) acrylate, polyisopropyl (meth) acrylate polyisobutyl (meth) acrylate, polybutyl (meth) acrylate, or the like. In another embodiment, a polycondensation polymer may be used, for example but not limited to, polyurea, polyamide paper, polyimide, polyester, or the like or combinations thereof. 
     Solid-state electrolyte composite  110  and  120  may include one or more sulfide solid-state electrolytes comprising one or more of a lithium-containing-element, a phosphorous-containing-element or a sulfur-containing-element. In another embodiment, the solid-state electrolyte composite  110  and  120  may include one or more oxysulfide solid-state electrolytes comprising one or more of a lithium-containing-element, a sulfur-containing-element or an oxygen-containing-element. In another embodiment, the solid-state electrolyte composite may comprise one or more of a halogen such as F, Cl, Br, or I. In another embodiment, the solid-state electrolyte composite may comprise one or more of a pseudo-halogen such as but not limited to CN, OH, SH, SCH, NH, NH 2 , NO 3 , BF 4 , or BH 4 . 
     Examples of sulfide solid electrolytes may include but are not limited to one or more of Li 2 S—P 2 S 5  Li 2 S—P 2 S 5 —LiX, Li 2 S–SiS 2 , Li 2 S—SiS 2 —LiX, Li 2 S—SiS 2 —P 2 S 5 , Li 2 S—SiS 2 —P 2 S 5 —LiX Li 2 S—SiS 2 —B 2 S 3 —LiX, Li 3 N—P 2 S 5 , Li 3 N— Li 2 S—P 2 S 5 —LiX and Li 2 S—B 2 S 3  where the components of each are mixed in a glass or glass ceramic forming ratio. Examples of an oxysulfide solid electrolytes may include one of more of Li 2 S—P 2 O 5 , Li 2 S—P 2 O 5 —LiX, Li 3 PO 4 —P 2 S 5 —LiX, Li 2 S—P 2 S 5 —Li 2 O, and Li 2 S—P 2 S 5 —-Li 2 O—LiX where the components of each are mixed in a glass or glass ceramic forming ratio. In some embodiments, Li 2 S—P 2 S 5  may represent one or more of a Li 3 PS 4 , Li 4 P 2 S 6 , Li 7 PS 6  and Li 7 P 3 S 11 . In some embodiments, Li 2 S —P 2 S 5 —LiX may represent one or more of Li 7-y PS 6-y X y  where 0 &lt; y ≤ 2 and X may be one or more halogen and or pseudo-halogen. In another embodiment, Li 2 S—P 2 S 5 — LiX may represent Li 7 P 2 S 8 X where X may be one or more halogen or a pseudo-halogen. In another embodiment, Li 2 S—P 2 S 5 —LiX may represent Li 8 P 3 S 11 X where X may be one or more halogen or a pseudo-halogen. 
     Additionally, the solid-state electrolyte material may vary in its structural makeup. In some embodiments, the solid-state electrolyte material may have a glass or glassy structure. In another embodiment, the solid-state electrolyte material may have a crystalline structure. In another embodiment, the solid-state electrolyte material may have a ceramic structure. In another embodiment, the solid-state electrolyte material may have a glassy ceramic structure. 
     One kind of solid electrolyte can be used alone, or two or more kinds of solid electrolytes can be used. In a case where two or more kinds of solid electrolytes are used, the two or more kinds of solid electrolytes may be mixed together, or each of the two or more kinds of solid electrolytes may be formed into two or more layers such that a multilayer structure is established. 
     The solid-state electrolyte composite  110  and  120  may include one or more materials other than a sulfide electrolyte or polymer. In some embodiments the material other than a sulfide electrolyte or polymer may be one or more of a lithium salt for example but not limited to LiPF 6 , LiBF 4 , LiClO 4 , LiN(CF 3 SO 2 ) 2 , LiN(FSO 2 ) 2 , or LiN(CF 3 CF 2 SO 2 ). In another embodiment the material other than a sulfide electrolyte or polymer may be one or more of an oxide for example but not limited to ZrO 2  or Al 2 O 3 . 
     In some embodiments the solid-state electrolyte composite layer  110  and  120  may be one or more of an electronically insulating material or electronically conducting layer. In another embodiment the solid-state electrolyte composite  110  and  120  may be referred to as an ion conducting material or ion conducting layer. 
     The composition of solid-state electrolyte composite  110  and  120  should be formulated such that solid-state electrolyte composite  110  and  120  may suitably deform and densify when pressure is applied to it. The deformation and densification properties may be defined according to predetermined values for Poisson ratio, viscosity, density, etc. Furthermore, viscous response of solid-state electrolyte composite  110  and  120  may be defined by predetermined responses such as shear-thinning, shear-thickening, thixotropic, power law responses. Additionally, one or more relationships between the properties of solid-state electrolyte composite  110  and  120  and electrode  130  may be defined and used for control. Additionally, solid-state electrolyte composite  110  and  120  should provide sufficient adhesion to electrode  130  and self-adhesion to support formation of encapsulated electrode  105 . Properties of solid-state electrolyte composite  110  and  120  and electrode  130  such as tack, surface energy, and wetting characteristics may be defined and used for control of process. Solid-state electrolyte composite  110  and  120  may include various volume and surface defects (indicated, for example, by open voids on the surface of and within solid-state electrolyte composite  110 ). These defects, if not removed, may lead to decreased lifetime or other performance issues with an electrochemical cell constructed therefrom. Additionally, solid-state electrolyte composites  110  and  120  may differ in various properties and/or composition. In addition to the previously mentioned thickness and material description, surface finish, ductility, malleability, mechanical stiffness (modulus of elasticity), the yield strength, elongation to failure, toughness, adhesion, and compression set may be predetermined and used for control of process. As illustrated through the progression of  FIGS.  1 A to  1 D , the various voids and surface defects are reduced in size or effectively eliminated after densification. 
     The dimensions of the solid-state electrolyte composite layer  110  and  120  should be such that when the solid-state electrolyte composite layer  110  and  120  is in contact with the electrode  130  that the boundary of the first face  145  and of the second face  140  of the solid-state electrolyte composite layer  110  and  120  extends beyond the boundary the first face  160  and second face  160  of the electrode  130 . 
     In some embodiments, the dimensions of the solid-state electrolyte composite layer  110  and  120  should be such that when the solid-state electrolyte composite layers  110  and  120  are in contact with the electrode  130 , the peripheral face  142  of solid-state electrolyte composite layer  110  and the peripheral face  152  of solid-state electrolyte composite layer  120  extends beyond the peripheral face  162  of the electrode  130 . 
     Peripheral face may be used to refer to at least two faces that are substantially perpendicular to the first and second face of the electrode layer or solid-state electrolyte composite layer. In some embodiments, peripheral face may be used to refer to each individual side of the electrode layer or solid-state electrolyte composite layer that is substantially perpendicular to the first and second face of the electrode layer or solid-state electrolyte composite layer. 
     The section of the solid-state electrolyte composite layer  110  that, when in contact with the electrode  130 , extends beyond the boundary of the first face  160  of electrode layer  130  may be referred to as the solid-state electrolyte composite layer outer edge  170  ( FIG.  1 B ). In some embodiments, the solid-state electrolyte composite layer outer edge  170  can be expressed by the difference between the width of the first face  145  of the solid-state electrolyte composite layer  110  and the width first face  160  of the electrode  130  when the solid-state electrolyte composite layer  110  and the electrode  130  are in contact or electrical contact. In another embodiment, the solid-state electrolyte composite layer outer edge  170  can be expressed by the difference between the length of the first face  145  of the solid-state electrolyte composite layer  110  and the length of the first face  160  of the electrode  130  when the solid-state electrolyte composite layer  110  the electrode  130  are in contact or electrical contact. The section of the solid-state electrolyte composite layer  120  that, when in contact with the electrode  130 , extends beyond the boundary of the first face  165  of electrode layer  130  may be referred to as the solid-state electrolyte composite layer outer edge  180 . In some embodiments, the solid-state electrolyte composite layer outer edge  180  can be expressed by the difference between the width of the first face  155  of the solid-state electrolyte composite layer  120  and the width of the first face  165  of the electrode  130  when the solid-state electrolyte composite layer  120  the electrode  130  are in contact or electrical contact. In another embodiment, the solid-state electrolyte composite layer outer edge  180  can be expressed by the difference between the length of the first face  155  of the solid-state electrolyte composite layer  120  and the length of the first face  165  of the electrode  130  when the solid-state electrolyte composite layer  120  the electrode  130  are in contact or electrical contact. 
     In some embodiments, the solid-state electrolyte composite layer outer edge  170  and the solid-state electrolyte composite layer outer edge  180  may have different overall area where the width of the solid-state electrolyte composite layer outer edge  170  may be smaller than that of the solid-state electrolyte composite layer outer edge  180 . In another embodiment, the width of the solid-state electrolyte composite layer outer edge  170  may be larger than that of the solid-state electrolyte composite layer outer edge  180 . In a further embodiment, the solid-state electrolyte composite layer  110  may have a width greater than that of the solid-state electrolyte composite layer  120 . In yet a further embodiment, the solid-state electrolyte composite layer  110  may have a width less than that of the solid-state electrolyte composite layer  120 . In another embodiment, the length of the solid-state electrolyte composite layer  110  may be greater than the length of the solid-state electrolyte composite layer  120 . In yet another embodiment, the length of the solid-state electrolyte composite layer  110  may be less than the length of the solid-state electrolyte composite layer  120   
     In some embodiments, the dimensions of the solid-state electrolyte composite layer  110  and  120  should be such that when the solid-state electrolyte composite layer  110  and  120  is in contact with the electrode  130  that the peripheral face  142  of the solid-state electrolyte composite layer  110  and the peripheral face  152  of the solid-state electrolyte composite layer  120  extends beyond only one side, S 1 , of the peripheral face  162  of the electrode  130 . In another embodiment, the dimensions of the solid-state electrolyte composite layer  110  and  120  should be such that when the solid-state electrolyte composite layer  110  and  120  is in contact with the electrode  130  the peripheral face  142  of the solid-state electrolyte composite layer  110  and the peripheral face  152  of the solid-state electrolyte composite layer  120  extends beyond two side of the peripheral face  162  of the electrode 13 where the two sides, S 1  and S 3 , are parallel to each other. In yet another embodiment, the dimensions of the solid-state electrolyte composite layer  110  and  120  should be such that when the solid-state electrolyte composite layer  110  and  120  is in contact with the electrode  130  that the peripheral face  142  of the solid-state electrolyte composite layer  110  and the peripheral face  152  of the solid-state electrolyte composite layer  120  extends beyond three sides of the peripheral face  162  of the electrode  130  where two sides, S 1  and S 3 , may be parallel to each other while possibly being perpendicular to the other, S 2. . In yet a further embodiment, the dimensions of the solid-state electrolyte composite layer  110  and  120  should be such that when the solid-state electrolyte composite layer  110  and  120  is in contact with the electrode  130 , the peripheral face  142  of the solid-state electrolyte composite layer  110  and the peripheral face  152  of the solid-state electrolyte composite layer  120  extends beyond four sides of the peripheral face  162  of the electrode  130  where; two sides, S 1  and S 3 , may be parallel to each other; two sides, S 2  and S 4 , may be parallel; but sides S 1  and S 3  may be perpendicular to S 2  and S 4 . 
     Referring to  FIG.  2   , the process  200  begins with step  210  wherein the various materials to be used in encapsulated electrode structure may be prepared. For example, to form an encapsulated electrode structure comprising an encapsulated anode structure, an anode active material such a metal foil made of one or more alkali metal for example but not limited to Li, Na, or K may be selected for the electrode. In another embodiment, the encapsulated anode active material may be one or more of an alkali metal alloy for example but not limited to Li-Al, Li-Zn, Li-Mg, Li-Na, Li-K, Li-Na-K, Li-In, Li-Au, Li-Ag, Na-Al, or Na-Zn. In yet another embodiment, the encapsulated anode active material may be one or more of an alkaline earth metal for example but not limited to Mg, Ca, or Ba. In a further embodiment, the encapsulated anode active material may be one or more of an alkaline earth metal alloy for example but not limited to Mg-Al, Mg-Zn, Mg-Ca, Mg-Na, Ca-Al, or Ca-Zn. In yet a further embodiment, the encapsulated anode may be one or more of a material with which lithium was deposited onto where the material alloys with lithium such as but not limited to silicon metal, silicon-carbon composites, Ag, Au, Sn, Pb, In, Ni, Al, or Sb. To form an encapsulated anode, solid-state electrolyte composite may be prepared as appropriate for use with the selected electrode material. In step  220 , the SSE and electrodes are layered. In step  230 , the SSE and electrodes are contacted to form a stack. In step  240 , pressure is applied to the stack. In step  250 , the stack is molded, and particularly the SSE layers are molded around the electrode to engulf the edges, and the electrode is encapsulated by the SSEs as pressure is applied. 
     In step  220 , the prepared electrode  130  and solid-state electrolyte composite  110  and  120  may be layered ( FIG.  1 B ) in preparation for contacting in step  230 . In some examples, dendrite inhibiting layers may be included between electrode  130  and solid-state electrolyte composite  110  and  120 . Furthermore, varied surface treatments may be applied to either electrode  130  or solid-state electrolyte composite  110  and  120  to improve wetting, deformation and/or defect conditions. After contacting, during step  240  pressure is applied substantially normal to the external surfaces of the contacted and layered electrode  130  and solid-state electrolyte composite  110  and  120 . The pressure may be applied uniformly or may vary spatially across the surface of the solid-state electrolyte composite external to the layered materials. Pressure may be applied non-uniform via fixed rigid mechanical means or conformally via pneumatic or hydraulic means. As discussed above, in one possible example, calendar rollers may be used. 
     As pressure is applied to the solid-state electrolyte composite  110  and  120 , the portion of the solid-state electrolyte composite  110  and  120  within the boundary of the first face  160  and second face  165  of electrode  130  may start to compact and densify while the SSE layers at the outer edges contact to encapsulate the electrode. Initially, the density of the portion of the solid-state electrolyte composite  110  and  120  that is beyond the boundary of the first face  160  and second face  165  of the electrode  130  denoted  170  and  180  remains substantially unchanged ( FIG.  1 B ) but then begins to also densify. In the case of calendar rollers with some separation distance is uniformly applied to the stack including both where the electrode is present as well as where the two SSE layers abut, the relative thickness differences between where there is the two abutting SSE layers and the thicker area where the upper and lower SSE layers include the electrode layer therebetween, results in a modestly lesser densification pressure where only the two SSE layers abut. Due to encapsulation, however, the relatively greater pressure is focused on densification and does not cause lateral extrusion or any lateral extrusion is quickly suppressed as the encapsulation is formed. 
     In some instances, the densification process is established such that the outer edge areas of the SSE layers abut and encapsulate the electrode prior to significant pressure application that might result in lateral extrusion of the electrode material. In this way, the electrode is encapsulated prior to pressure application that might otherwise cause lateral extrusion of the electrode material. In such a case, for example, a first “light” lamination pressure may be applied to cause the SSE to form around the electrode. Then, a second “heavy” lamination may be applied to fully densify the layers and form the protected electrode. Light and heavy pressures will depend on the materials present, electrode extrusion characteristics, and the like. Such a technique may be particularly useful when a relatively thick electrode is used as the SSE layer will have to deform more around the edges of the electrode before the SSE layers can touch and fuse. In many instances, however, there may be a consistent lamination pressure applied (not two or more pressures) as only one lamination/densification step is needed as the SSE layer is able to fuse before the lithium extrudes past it. In the case of Lithium, for example, some Lithium flow or extrusion may occur but the fusing of the SSE layers happens so quickly that there is not a detrimental effect from very minimal lateral flow of the Lithium. 
     With the continued application of pressure to the solid-state electrolyte composite now  112  and  122 , the portion of the solid-state electrolyte composite  112  and  122  within the boundary of the first face  160  and second face  165  of electrode  130  may further compact and densify. During this compaction and densification, the portion of the solid-state electrolyte composite  112  and  122  that is beyond the outer boundary of the first face  160  and second face  165  of electrode  132  may come in contact, forming an encapsulated electrode  105 . With the continued application of pressure, the portion of the solid-state electrolyte composite  112  and  122  within the boundary of the first face  160  and second face  165  of electrode  132  may reach the desired density. Additionally, the density of the section of the solid-state electrolyte composite  170  and  180  that are now in contact increases but remains at a lower density than that of the portion of the solid-state electrolyte composite  112  and  122  within the boundary of the first face  160  and second face  165  of electrode  132 . 
     In some embodiments, the portion of the solid-state electrolyte composite that is beyond the boundary of the first face  160  and second face  165  of electrode  132  may come in contact and fuse during the densification process. 
     During the application of pressure, electrode  130  may be deformed though various stages (initial deformation into electrode  132  and final deformation into thinner electrode  135 ). This deformation of the electrode is restricted due to its being encapsulated by the solid-state electrolyte composite  125 , which provides mechanical entrapment of the electrode. This physical structure allows for the application of pressures that far exceed the point at which an electrode active material such as lithium metal or lithium metal alloy would normally deform and flow undesirably. Fully encapsulating the lithium metal or other electrode active materials with the solid-state electrolyte composite prior to fully densifying the layers prevents the lithium or other electrode active material from extruding past the peripheral face  142  or  152  of the solid-state electrolyte composite  110  and  120  or otherwise deforming undesirably. 
     As the density of solid-state electrolyte composite  110  and  120  increases, its ionic conductivity increases. With the density difference, the portion of solid-state electrolyte composite  110  and  120  within the boundary of the first face  160  and second face  165  of electrode  130  may have a higher ionic conductivity compared to the portion of solid-state electrolyte composite  110  and  120  that is outside the boundary of the first face  160  and second face  165  of the electrode  130 . Ions will preferentially follow the path of least resistance (highest ionic conductivity) and thus, the ion conduction will take place primarily within the boundary of the first face  160  and second face  165  of electrode  130  or within the peripheral face  162  of electrode  130 . 
     As the application of pressure and the resulting densification process continues, defects which may occur in solid-state electrolyte composite  110  and  120  may be reduced. Densification may utilize a time range from 0.01 seconds to 5 minutes and a pressure range from 100 psi to 400,000 psi. In another embodiment, the pressure may range from 500 psi to 50,000 psi. In a further embodiment, the pressure may range from 1000 psi to 20,000 psi. Applied pressure may vary, for example, by an increasing ramp of 100 to 1000 psi/s with time under pressure in the range of 0.01 s to 300 s. Densification and or calendaring may occur in a temperature range of approximately -10° C. to 200° C. In another embodiment, the temperature range may be between 0° C. to 150° C. In another embodiment, the temperature range may be between 10° C. to 125° C. In another embodiment, the temperature range may be between 25° C. to 120° C. In another embodiment, the temperature range may be between 45° C. to 115° C. In another embodiment, the temperature range may be between 70° C. to 110° C. Any of the external pressures and/or temperatures may be constant or variable over the process time employed. 
     Pressure should be appropriately applied such that solid-state electrolyte composite  110  and  120  come into contact to complete the encapsulation in step  250 . In some embodiments, the solid-state electrolyte composite  110  and  120  may adhere under the applied pressure. 
     If insufficient pressure is used, the solid-state electrolyte composite  110  and  120  or  112  and  122  may not come into contact with each other. In the circumstance where adhesion of the solid-state electrolyte composite  110  and  120  is desired, if insufficient pressure is used, adhesion of the contacted portions may be insufficient to ensure sealing of the encapsulation. Alternatively, if excessive pressure is used, solid-state electrolyte composite  110  and  120  may deform non-uniformly producing wrinkling and or buckling resulting in failed encapsulation. If densified solid-state electrolyte composite  110  and  120  is utilized, the portions extending beyond the boundary of the first and second face of electrode  130  denoted  170  and  180  may not sufficiently adhere and complete the encapsulation. To assist in the formation of the portions extending outside of the boundary of the first and second face of electrode  130  denoted  170  and  180 , solid-state electrolyte composite  110  and  120  may vary in extension beyond the boundary of the first and second face of electrode  130  denoted  170  and  180 . This variance may be expressed by comparing the ratio between the width of the solid-electrolyte composite  110  and  120  (W SEC ) to the width of the electrode  130  (W E ). 
     If the yield strength of one or more materials of the electrode is less than the pressure needed to densify the solid-electrolyte composite  110  and  120 , then the width of the pre-densified solid-electrolyte composite layer may be more than the width of the electrode  130  or W SEC  ≥ W E . Having a W SEC  ≥ W E  configuration allows for the solid-electrolyte composite to fully encapsulate the electrode  130  preventing one or more materials of the electrode form extruding beyond the peripheral face  142  or  152  of the solid-state electrolyte composite  110  and  120  when pressures greater than the yield strengths of one or more of the electrode components is applied. If the electrode is not fully encapsulated and pressure greater than the yield strength of one or more of its components is applied, then one or more of those components may extrude beyond the peripheral face  142  or  152  of the solid-electrolyte composite  110  and  120 . This may cause shorting of the electrochemical cell. 
     The electrode  130  may contain one or more materials that have a room temperature compressive yield strength of 50 psi to 400,000 psi. In some embodiments, the room temperature yield strength of an electrode may be 105 psi when the electrode contains materials such as lithium metal. In another embodiment, the room temperature yield strength of the electrode may be 9000 psi when the electrode contains materials such as copper. In another embodiment, the room temperature yield strength of the electrode may be 30,000 psi when the electrode contains materials such as magnesium. In a further embodiment, the room temperature yield strength of the electrode may be 380,000 psi when the electrode contains materials such as steel. 
       FIGS.  3 A- 3 C  are a set of pictorial representations of process steps for partitioning an encapsulated electrode. In  FIG.  3 A , the encapsulated electrode  310  and the shearing device  320  may be appropriately positioned. In  FIG.  3 B , shearing device  320  may be brought into contact with encapsulated electrode  310  and shearing initiated. In  FIG.  3 C , shearing device  320  may be designed with a cutting edge and body formed to facilitate the shearing of the solid electrolyte composite along the edges of the encapsulated electrode  310  as well as the transport of the solid-state electrolyte composite encapsulating the electrode itself such that the partitioned encapsulated electrodes  330  and  331  are trimmed by the shearing action. 
     In some embodiments, the shear device may contain one or more cutting instruments such as polymeric, metallic or ceramic blades or edges. In other embodiments the shear device may be a device capable of producing a source of electromagnetic radiation such as microwave, infrared, visible, or ultraviolet or electromagnetic radiation is in the form of a laser. In a further embodiment the shear device may be capable of producing plasma in various temperature ranges ranging from room temperature to 1500 C. 
     Process  400  begins with step  410  wherein the encapsulated electrode may be prepared for partitioning. Preparation may include, for example, bringing the encapsulated electrode to a temperature suitable for partitioning. In process step  420 , the encapsulated electrode and the shearing device may be appropriately positioned. In step  430 , shearing device may be brought into contact with encapsulated electrode and shearing initiated. In step  440 , the shearing device may be removed and in step  450 , the partitioned material may be separated. Process  400  ends with step  460  and may be followed by subsequent application of process  200  in  FIG.  2    to ensure re-encapsulation or removal of any added defects. 
       FIG.  5 A  is a 3-dimensional representation of electrode  500  (also shown in  FIG.  1 A  and  FIG.  1 B ). Electrode  500  can have a multitude of faces including a peripheral face  510 , a first face  520 , and a second face  530 . In some embodiments, a peripheral face  510  may be substantially perpendicular to the first face  520  and second face  530 . 
       FIG.  5 B  shows a 3-dimensional representation of the solid-state electrolyte composite  540  (also shown as SSE  110  and/or  120  of  FIG.  1 A  and  FIG.  1 B ). The SSE  540  can have a multitude of faces including a peripheral face  550 , a first face  560 , and a second face  570 . In some embodiments, the peripheral face  550  may be substantially perpendicular to the first face  560  and second face  560 . 
     In  FIGS.  5 A- 5 D  it should be recognized that the representations of the electrode and SSE are not necessarily to scale. In many instances, the thickness of the peripheral portions of these components will be relatively less in comparison to the length and width dimension depicted. As such, a peripheral face of the electrode will be more akin to an edge or boundary. 
     The solid-state electrolyte composite layer  540  may be constructed in such a way that the solid-state electrolyte composite in the form of a slurry, dry powder, melts, solution, or deposition is applied to a carrier. This is completed in a manner such that when the solid-state electrolyte composite is applied to a carrier, a layer is formed. This may be accomplished by means of coating, casting, dry powder, or deposition. The carrier may comprise one or more of a metal foil or plastic film. In some embodiments the carrier may be removed from the solid-state electrolyte composite layer  540  before or after any compression or densification. 
       FIG.  5 C  shows a pictorial representation of the encapsulated electrode structure  590  before the layers are assembled, which is a 3-dimensional pictorial representation of encapsulated electrode structure before the layers are assembled. One layer of the encapsulated electrode structure  590  is a first solid-state electrolyte composite (SSE)  541  that has a top surface  561 , a bottom surface  571 , and a peripheral surface  554 . Another layer of the encapsulated electrode structure  590  is the electrode  505  that has a top surface  521 , a bottom surface  531 , and a peripheral surface  556 . Yet another layer of the encapsulated electrode structure  590  is a second SSE  542  that has a top surface  572 , a bottom surface  562 , and a peripheral surface  555 . The first SSE  541  is arranged so as to be attached to the electrode  505 , wherein the bottom surface of the first SSE  571  is attached to the top surface of the electrode  521 . The bottom surface of the electrode  531  is to be attached to the top surface of the second SSE  572 . 
       FIG.  5 D  shows an encapsulated electrode structure  590  after the continued application of pressure is applied to the arrangement, so that the SSE  541  and SSE  542  come in contact to form a unified SSE  525 , which enclosed electrode  535 . 
       FIGS.  7 A- 7 C  depict scanning electron microscope (SEM) images of three different protected electrode stacks - e.g., SSE-Electrode-SSE - processed according to the techniques discussed herein. 
     In all of the examples, the electrolyte material is a Li 3 PS 4  sulfide electrolyte. Prior to formation of the protected electrode, the electrode includes a sheet of Lithium Metal foil 35 um thick cut into square pieces with an area of about 1 in 2  (having a length and width of about 1 in.). The Lithium metal squares were then stored in an Argon environment prior to formation. 
     To form the solid electrolyte layer (separator layer), 92%w/w of the Li 3 PS 4  sulfide electrolyte and 8%w/w of a Styrene-butadiene Rubber (SBR) was blended together with Xylenes using a Flacktek mixer. This mixture was then cast onto a 25 um thick carrier foil made of Aluminum using a 200 um blade. The coated layer was then dried in inert conditions. This solid electrolyte layer was then cut into squares pieces with an area of about 1.9 in 2  or with a length and width of about 1.375 in. 
     The SSE layer was about 0.375 inches wider and 0.375 inches longer than the electrode layer. Therefore, if the square electrode was centered between the square SSE layers, there would be about a 0.1875 inch outer edge of the upper and lower SSE layers that face each other and where there is no electrode material therebetween. During formation and densification, a boundary region of about 0.1875 inch of SSE material will contact and form the electrode protection boundary discussed herein. Because the overhang surrounds the electrode on all four sides, the protection forms a square periphery around the electrode. 
     To demonstrate the effectiveness of the protected electrode technique discussed herein and some characterizing features of the same, three different experiments were performed against the sample materials described above. 
     In the first example, the protected electrode was formed as follows. The square piece of lithium metal foil, as discussed above, was place on top of and centered on a first 45 um thick SSE layer such that the lithium metal came into contact with the solid electrolyte. In this configuration, the length and width of the Solid Electrolyte layer extended past the length and width of the lithium metal foil by around 0.1875 inches. A second 45 um thick SSE layer layer was placed on top of and centered on the Lithium metal foil such that the solid electrolyte came into contact with the lithium metal foil. In this configuration, the length and width of the second Solid Electrolyte layer extended past length and width of the lithium metal foil by around 0.1875 inches. The resulting stack is structed such that the layers followed this order: a layer of aluminum foil followed by a Separator Layer containing a solid electrolyte follow by a layers of Lithium Metal followed by a Separator Layer containing a solid electrolyte followed by a layer of Aluminum foil. As mentioned above, the SSE layers directly abutted each other in a square periphery around the electrode, with the abutting dimension being 0.1875 inches. 
     The stack was then placed in a press and, at room temperature, was laminated by applying a pressure of around 4200 psi (or 8200 psi) for a duration of 4 seconds, and after the 4 seconds, the pressure removed.  FIG.  7 A  is an SEM image through a slice of a protected electrode structure  700  illustrating an electrode  702 , an upper (first) SSE layer  704 , a lower (second) SSE layer  706  and a boundary region  708  where the upper and lower SSE layers have been laminated together forming a consistent combined “fused” material with no visually identifiable boundary therebetween. In some instances, the SSE layers, such as in cases with larger SSE particle sizes than in the illustrated examples, may not fuse but rather may form an interlocking network able to block electrode extrusion. The lamination of the upper and lower SSE layers also formed an encapsulating (protection) area at the peripheral face of the electrode thereby constraining the electrode from extrusion and enhancing the densification process between the SSE layers and the electrode. 
     In the example of  FIG.  7 A , little or no extrusion of the electrode occurred prior to the SSE layers fusing to form the boundary region  708 . Thus, as shown, the electrode at the boundary region defines a blunt end reflecting little or no extrusion. This is contrast to the relatively more pointed electrodes resulting from some extrusion and as discussed in more detail below with regard to  FIGS.  7 B and  7 C . 
     The protected electrode structure of a second example was prepared in the same way as the first example with the exception that the stack was laminated by applying a pressure of around 8400 psi for a duration of 4 seconds, and after the 4 seconds, the pressure removed. As such, the lamination pressure was about twice that applied in the first example.  FIG.  7 B  is an SEM image through a slice of a protected electrode structure  710  illustrating an electrode  712 , an upper (first) SSE layer  714 , a lower (second) SSE layer  716  and a boundary region  718  where the upper and lower SSE layers have been laminated together forming a consistent material with no visually identifiable boundary therebetween. The lamination of the upper and lower SSE layers also formed an encapsulating (protection) area at the peripheral face of the electrode thereby constraining the electrode from extrusion and enhancing the densification process between the SSE layers and the electrode. 
     In  FIG.  7 B  (as well as  FIG.  7 C ), the electrode defines a pointed area  730  (pointed area  732 ) where the SSE layer  714  and layer  716  have fused and at the boundary region  718 . The pointed area indicates very modest extrusion of the electrode toward the boundary area as the lamination pressure is applied to the stack to fuse the SSE layers and protect the electrode. The SEM images is along a section of the densified stack. Leading out to the pointed area  730 , the electrode defines two faces that converge at the point. Similarly, the SSE layers define two surfaces that converge toward the boundary region where they are fused. In both of  FIGS.  7 B and  7 C , the SEM image at the respective points  730  and  732 , is shown with both angular and thickness measurements. Referring first to  FIG.  7 B , the point is about 38 degrees, with the upper and lower SSE layers at an angle of 19 degrees relative to plane of the electrode where no extrusion is occurring (or 71 degrees as shown in the figure relative to a perpendicular line between upper and lower planar face of electrode where not extruded). Referring to  FIG.  7 C , the point is about 49 degrees, with the upper and lower SSE layers at an angle of 24 and 25 degrees (or 66 and 65 degrees as shown in the figure). In general, the angle of the pointed area may be in the range of 10 degrees to 60 degrees. 
     To further illustrate the formation of the protection boundary of the fused upper and lower layers, along with modest extrusion that is terminated when the boundary forms,  FIGS.  7 B and  7 C  also include SEM images with electrode thickness measurements where the respective points are formed. 
     In the final example of  FIG.  7 C , the protected electrode structure was prepared in the same way as the second example and at the same pressure except the thickness of the first and second SSE layers used was 75 um. The electrode layer thickness was the same in all three examples.  FIG.  7 C  is an SEM image through a slice of a protected electrode structure  720  illustrating an electrode  722 , an upper (first) SSE layer  724 , a lower (second) SSE layer  726  and a boundary region  728  where the upper and lower SSE layers have been laminated together forming a consistent material with no visually identifiable boundary therebetween. The lamination of the upper and lower SSE layers also formed an encapsulating (protection) area at the peripheral face of the electrode thereby constraining the electrode from extrusion and enhancing the densification process between the SSE layers and the electrode. 
     Table 1 illustrates the void differences between the three examples. It can be seen that the void size is generally less in the SSE layers above and below the electrode as compared to the void thickness of the SSE layers outside the boundary of the electrode. At higher lamination pressure, it can be seen that the difference in void size where there are three layers as opposed to the boundary area where there are only two layers of abutting SSE is significantly higher as compared to the lower pressure lamination pressure. 
     
       
         
          TABLE 1
           
               
               
               
               
               
               
             
               
                 Comparison in void space analysis of the three example protected electrode structures and processing conditions 
               
               
                   
                 Lamination Pressure (psi) 
                 Separator Layer Thickness (um) 
                 Average Void Fraction -Above/Below Electrode (%) 
                 Average Void Fraction -Beyond Electrode (%) 
                 % Difference 
               
             
            
               
                 Example 1 
                 4200 
                 45 
                 37.4 
                 38.6 
                 3.2 
               
               
                 Example 2 
                 8400 
                 45 
                 34.5 
                 40.5 
                 17.4 
               
               
                 Example 3 
                 8400 
                 75 
                 29.8 
                 34.5 
                 15.8 
               
            
           
         
       
     
     As will be seen from the experimental data and SEM images, by encapsulating the electrode during densification, the void size may be reduced more substantially where the electrode and SSE layers abut as compared to in the outer edge areas where the SSE layers abut to encapsulate the electrode. In addition, by encapsulating the electrode, it is understood that greater relative densification (relatively smaller void sizes) may occur as compared to densification of like structures under the same pressures with the only distinction being between an encapsulated electrode and a non-encapsulated electrode. In the case of a non-encapsulated electrode, some material, particularly when considering relatively soft Lithium anode materials, will laterally extrude under densification pressures whereas by trapping the electrode through encapsulation by the SSE layers, lateral extrusion is blocked by the relatively harder SSE material thereby increasing the relatively effectiveness of the densification process to relatively reduce void size and generate relatively greater material contact between the electrode layer and the SSE layers. 
     Features described above as well as those claimed below may be combined in various ways without departing from the scope hereof. It should thus be noted that the matter contained in the above description or shown in the accompanying drawings should be interpreted as illustrative and not in a limiting sense. The above-described embodiments should be considered as examples, rather than as limiting the scope of the disclosure. In addition to the foregoing embodiments, review of the detailed description and accompanying drawings will show that there are other embodiments. Accordingly, many combinations, permutations, variations and modifications of the foregoing embodiments not set forth explicitly herein will nevertheless fall within the scope of this disclosure. The following claims are intended to cover generic and specific features described herein, as well as all statements of the scope of the present method and system, which, as a matter of language, might be said to fall there between.