BI-layer anode structure for lithium batteries

Abstract

The present disclosure relates to an electrochemical cell comprising a cathode, an electrolyte, and an anode with a laminated bi-layer structure. This bi-layer anode addresses interface instability challenges in lithium metal batteries through a protective first layer and high-capacity second layer that are mechanically integrated via rolling. The first layer comprises lithium-containing materials including lithium-magnesium alloy, lithium nitride, LLZO, or combinations thereof, providing interfacial stabilization and preventing polysulfide shuttling. The second layer comprises lithium-magnesium alloy, lithium titanate, or combinations thereof, contributing substantial capacity. This configuration eliminates interface resistance buildup, reduces costs through selective use of expensive protective materials, and enables practical utilization of high-magnesium content alloys.

Description

BI-LAYER ANODE STRUCTURE FOR LITHIUM BATTERIESInventors: Yunguang ZhuYongtao MengAssignee: Lyten, Inc.145 Baytech Dr.San Jose, CA 95134-2303United States of AmericaEntity: SmallBI-LAYER ANODE STRUCTURE FOR LITHIUM BATTERIESCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Application No.63 / 712,320, titled BLLAYER ANODE STRUCTURE FOR LITHIUM BATTERIES, filed October 25, 2024, which is hereby incorporated by reference in its entirety.FIELD OF THE INVENTION

[0002] The present disclosure relates to battery anode structures, and more particularly to a bi-layer anode structure.BACKGROUND

[0003] Lithium metal batteries represent a promising technology for nextgeneration energy storage applications due to their high theoretical capacity and energy density. However, the practical implementation of lithium metal anodes faces substantial challenges related to interface stability between the anode and electrolyte. During battery operation, lithium metal undergoes plating and stripping processes that can lead to the formation of lithium dendrites, consumption of electrolyte, and buildup of interfacial resistance. These phenomena result in capacity loss, reduced cycle life, and potential safety concerns, limiting the commercial viability of lithium metal battery systems.

[0004] Existing approaches to address anode-electrolyte interface instability encounter several technical obstacles. Conventional coaling methods, such as spray coating or bar coating with polymer or ceramic materials, often suffer from poor adhesion, non-uniform coverage, and mechanical degradation during cycling. Additionally, single-layer protective coatings may compromise the overall energy density of the battery system due to added weight and volume without contributing to capacity. The formation of solid electrolyte interphase (SEI) layers, while naturally occurring, can be inconsistent and may not provide adequate long-term protection against electrolyte decomposition and dendrite formation.

[0005] For instance, in lithium-sulfur battery systems, polysulfide shuttling between the cathode and anode can cause rapid capacity fade and poor coulombic efficiency when protective measures are inadequate. Current surface modification techniques may initially improve performance but often fail to maintain their protective properties over extended cycling periods. Another example involves high-magnesium content lithium-magnesium alloy anodes, which exhibit activation issues and slow lithium diffusion kinetics that limit their practical capacity ulilizalion, despite their potential for improved cycle life and structural stability.

[0006] As such, there is thus a need for addressing these and / or other issues associated with the prior art.SUMMARY

[0007] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

[0008] According to an aspect of the present disclosure, a battery anode is provided. The battery anode includes a first layer comprising a first lithium-containing material and a second layer comprising a second lithium-containing material. The first layer and the second layer are laminated together to form a bi-layer structure.

[0009] According to other aspects of the present disclosure, the battery anode may include one or more of the following features. The first layer may be configured to provide at least one of stable solid electrolyte interphase formation, lithium nucleation, fast lithium diffusion, or corrosion resistance. The first layer may have a thickness between 2 micrometers and 50 micrometers. The second layer may be configured to provide fast lithium diffusion with a stable structure. The first lithium-containing material may comprise a lithium-magnesium alloy. The lithiummagnesium alloy may be Li90Mgl0. The second lithium-containing material may comprise lithium titanate. The first layer may further comprise a ceramic material. The ceramic material may be lithium lanthanum zirconium oxide. The first layer and the second layer may be laminated together using a rolling process. The bi-layer structure may be configured to prevent side reactions with an electrolyte in a lithiumsulfur battery.

[0010] According to another aspect of the present disclosure, an electrochemical cell is provided. The electrochemical cell includes a cathode, an electrolyte, and an anode comprising a laminated bi-layer structure. The laminated bi-layer structure includes a first layer comprising a first lithium-containing material and a second layer comprising a second lithium-containing material.

[0011] According to other aspects of the present disclosure, the electrochemical cell may include one or more of the following features. The first lithium-containingmaterial or the second lithium-containing material may be configured to improve lithium nucleation or maintain structure. The first layer and second layer may reduce polysulfide transfer.

[0012] The foregoing general description of the illustrative embodiments and the following detailed description thereof are merely exemplary aspects of the teachings of this disclosure and are not restrictive.BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Non-limiting and non-exhausli vc examples are described with reference to the following figures.

[0014] FIG. 1 illustrates a bi -layer anode system with multiple stacked layers, according to aspects of the present disclosure.

[0015] FIG. 2 depicts a sequence diagram of a bi-layer anode assembly manufacturing process, according to an embodiment.

[0016] FIG. 3 shows scanning electron microscope images of a bi-layer anode structure, according to aspects of the present disclosure.

[0017] FIG. 4 illustrates energy dispersive spectroscopy analysis results of bi-layer structures, according to an embodiment.

[0018] FIG. 5 depicts a discharge capacity graph comparing different anode compositions, according to aspects of the present disclosure.

[0019] FIG. 6 shows a discharge capacity graph for various magnesium-rich configurations, according to an embodiment.

[0020] FIG. 7 illustrates a discharge capacity graph with varying magnesium content compositions, according to aspects of the present disclosure.

[0021] FIG. 8 depicts a discharge capacity graph comparing different lithiummagnesium compositions, according to an embodiment.

[0022] FIG. 9 shows scanning electron microscope images of a baseline anode structure, according to aspects of the present disclosure.

[0023] FIG. 10 illustrates scanning electron microscope images of a bi-layer anode structure, according to an embodiment.DETAILED DESCRIPTION

[0024] The following description sets forth exemplary aspects of the present disclosure. It should be recognized, however, that such description is not intended as a limitation on the scope of the present disclosure. Rather, the description also encompasses combinations and modifications to those exemplary aspects described herein.

[0025] The present disclosure relates to the field of lithium metal battery technology, specifically focusing on advanced anode structures for high-energy density electrochemical energy storage systems. Lithium metal batteries represent a critical technology for next-generation applications requiring superior energy storage capabilities, including electric vehicles, grid-scale energy storage, and portable electronic devices.

[0026] Current lithium metal battery systems face significant challenges related to anode-electrolyte interface instability during battery operation. The plating and stripping processes inherent to lithium metal anodes lead to dendrite formation, electrolyte consumption, and interfacial resistance buildup, resulting in capacity loss, reduced cycle life, and safety concerns. Existing surface modification approaches, such as conventional coating methods using polymers or ceramics, suffer from poor adhesion, non-uniform coverage, and mechanical degradation during cycling. Additionally, single-layer protective systems often compromise energy density due to added weight without contributing to capacity, while high-magnesium content lithium-magnesium alloy anodes exhibit activation issues and slow lithium diffusion kinetics that limit practical capacity utilization.

[0027] The present disclosure addresses these challenges through a bi-layer anode structure comprising laminated layers of lithium-containing materials specifically configured to stabilize the anode-electrolyte interface. The bi-layer configuration includes a first layer designed to provide stable solid electrolyte interphase formation, lithium nucleation, fast lithium diffusion, or corrosion resistance, and a second layer configured to provide fast lithium diffusion with structural stability. This laminated structure eliminates interface resistance buildup between layers while maintaining protective properties throughout extended cycling periods, effectively preventingpolysulfide shuttling in lithium-sulfur battery systems and improving coulombic efficiency.

[0028] The disclosed bi-layer structure offers additional advantages including cost efficiency through selective use of expensive materials only in thin protective layers rather than bulk electrodes, reduced overall system weight compared to conventional protective coating approaches, and the ability to unlock lithium capacity in high-magnesium content alloys that would otherwise exhibit poor activation characteristics. The lamination process creates seamless integration between layers without clear boundaries that could introduce resistance, while the modular design allows for optimization of individual layer thicknesses and compositions to achieve specific performance targets for different battery applications.Definitions and Use of Figures

[0029] Some of the terms used in this description are defined below for easy reference. The presented terms and their respective definitions are not rigidly restricted to these definitions — a term may be further defined by the term’s use within this disclosure. The term “exemplary” is used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects or designs. Rather, use of the word exemplary is intended to present concepts in a concrete fashion. As used in this application and the appended claims, the term “or” is intended to mean an inclusive “or” rather than an exclusive “or”. That is, unless specified otherwise, or is clear from the context, “X employs A or B” is intended to mean any of the natural inclusive permutations. That is, if X employs A, X employs B, or X employs both A and B, then “X employs A or B” is satisfied under any of the foregoing instances. As used herein, at least one of A or B means at least one of A, or at least one of B, or at least one of both A and B. In other words, this phrase is disjunctive. The articles “a” and “an” as used in this application and the appended claims should generally be construed to mean “one or more” unless specified otherwise or is clear from the context to be directed to a singular form.

[0030] Various embodiments are described herein with reference to the figures. It should be noted that the figures are not necessarily drawn to scale, and that elementsof similar structures or functions are sometimes represented by like reference characters throughout the figures. It should also be noted that the figures are only intended to facilitate the description of the disclosed embodiments — they are not representative of an exhaustive treatment of all possible embodiments, and they are not intended to impute any limitation as to the scope of the claims. In addition, an illustrated embodiment need not portray all aspects or advantages of usage in any particular environment.

[0031] An aspect or an advantage described in conjunction with a particular embodiment is not necessarily limited to that embodiment and can be practiced in any other embodiments even if not so illustrated. References throughout this specification to “some embodiments” or “other embodiments” refer to a parlicular feature, structure, material or characteristic described in connection with the embodiments as being included in at least one embodiment. Thus, the appearance of the phrases “in some embodiments” or “in other embodiments” in various places throughout this specification are not necessarily referring to the same embodiment or embodiments. The disclosed embodiments are not intended to be limiting of the claims.Descriptions of Exemplary Embodiments

[0032] FIG. 1 illustrates a bi -layer anode system 100, in accordance with one embodiment. As an option, the bi-layer anode system 100 may be implemented in the context of any one or more of the embodiments set forth in any previous and / or subsequent Figures and / or description thereof. Of course, however, the bi-layer anode system 100 may be implemented in the context of any desired environment. Further, the aforementioned definitions may equally apply to the description below.

[0033] The bi-layer anode system 100 comprises multiple layers arranged in a stacked configuration with distinct material compositions and functional properties. The bi-layer anode system 100 includes a top layer having a thickness of less than 10 micrometers and a bottom layer having a thickness of approximately 90 micrometers. The top layer may comprise various lithium-containing materials selected based on specific functional requirements including stable solid electrolyte interphase formation, lithium nucleation enhancement, fast lithium diffusion, and / or corrosion resistance properties. The bottom layer may be configured to provide fast lithiumdiffusion with structural stability throughout extended cycling periods. In some cases, the bi-layer anode system 100 may be specifically configured for lithium-sulfur battery applications where polysulfide shuttling mitigation and coulombic efficiency improvement are desired performance characteristics.

[0034] The top layer of the bi-layer anode system 100 may comprise lithiumstrontium (Li-Sr) material for strong SEI formation functionality. The lithiumstrontium material may facilitate the formation of a stable solid electrolyte interphase layer that reduces unwanted side reactions between the anode and electrolyte during battery operation. In some cases, the lithium-strontium composition may provide enhanced interfacial stability through the formation of strontium fluoride compounds that act as protective barriers against electrolyte decomposition. The strong SEI formation capability of lithium-strontium materials may contribute to improved cycle life and reduced capacity fade in lithium metal battery systems. The lithium-strontium layer may maintain its protective properties throughout repeated plating and stripping cycles while minimizing the buildup of resistive interfacial layers that could degrade battery performance.

[0035] Alternatively, the top layer of the bi-layer anode system 100 may comprise lithium-indium (Li-In) liquid metal for improved lithium nucleation. The lithiumindium liquid metal composition may provide preferential nucleation sites that promote uniform lithium deposition during charging processes. In some cases, the liquid metal properties of lithium-indium alloys may enable self-healing characteristics that maintain surface uniformity even after multiple charge-discharge cycles. The improved lithium nucleation provided by lithium-indium materials may reduce dendrite formation and associated safety concerns while enhancing the overall electrochemical performance of the anode structure. The lithium-indium composition may exhibit favorable wetting properties that facilitate intimate contact with the underlying bottom layer and promote efficient lithium ion transport across the bi-layer interface.

[0036] In various embodiments, the top layer of the bi-layer anode system 100 may comprise magnesium-rich lithium magnesium alloy with LTO having greater than 30 weight percent magnesium for low reactivity and structural stability. The high magnesium content may provide enhanced corrosion resistance and reduced reactivitywith electrolyte components compared to conventional lithium metal anodes. In some cases, the magnesium-rich composition may maintain structural integrity during volume changes associated with lithium plating and stripping processes. The LTO component may contribute to the overall stability of the top layer while providing pathways for lithium ion conduction. The combination of high magnesium content and LTO may result in a protective layer that exhibits minimal degradation over extended cycling periods while maintaining low interfacial resistance with the electrolyte.

[0037] The top layer of the bi-layer anode system 100 may also comprise magnesium-rich lithium magnesium alloy with LLZO having greater than 30 weight percent magnesium for low reactivity and good lithium ion conductivity. The LLZO component may provide increased lithium ion conductivity compared to other ceramic materials while maintaining chemical stability in contact with lithium metal. In some cases, the magnesium-rich lithium magnesium alloy with LLZO may exhibit enhanced lithium ion transport properties that facilitate efficient charge transfer across the anode-electrolyte interface. The high magnesium content may contribute to improved mechanical properties and reduced susceptibility to dendrite penetration. The LLZO component may also provide thermal stability and safety benefits through its ceramic nature and resistance to thermal runaway conditions.

[0038] In various embodiments, the top layer of the bi-layer anode system 100 may comprise a magnesium-rich lithium-magnesium alloy combined with lithium nitride (Li3N) having greater than 30 weight percent for enhanced structural stability and reduced reactivity with electrolyte components compared to conventional lithium metal surfaces. In some cases, the lithium nitride component may provide superior lithium ion conductivity and facilitate rapid lithium transport across the protective layer interface, enabling efficient electrochemical activity while maintaining barrier properties against polysulfide shuttling. The combination of high magnesium content and lithium nitride may result in a protective layer that exhibits excellent chemical stability in contact with lithium-sulfur electrolyte systems while providing preferential nucleation sites for uniform lithium deposition during charging processes. The magnesium-rich Li-Mg / Li3N configuration may also contribute to improved thermal stability and safety characteristics through the enhanced melting point properties ofthe magnesium-rich alloy and the ionic conductivity benefits of the lithium nitride phase, enabling stable operation under high-rate charging conditions and elevated temperature environments.

[0039] The bottom layer of the bi-layer anode system 100 may comprise Li97Mg3 alloy composition that provides fast lithium diffusion with structural stability. The Li97Mg3 composition may offer an optimal balance between lithium content for capacity and magnesium content for structural enhancement. In some cases, the relatively low magnesium content in the bottom layer may ensure adequate lithium diffusion kinetics while providing sufficient alloying benefits to improve mechanical properties compared to pure lithium metal. The Li97Mg3 alloy may exhibit reduced volume expansion during lithium insertion and extraction processes, thereby maintaining dimensional stability of the overall anode structure. The bottom layer composition may also provide a stable substrate for the overlying top layer while contributing to the overall capacity of the bi-layer anode system 100.

[0040] The bottom layer of the bi-layer anode system 100 may comprise Li97Mg3 / LTO composition that provides an optimal balance between high lithium content for capacity contribution and structural enhancement through magnesium alloying and lithium titanate integration. The Li97Mg3 alloy component may offer superior lithium diffusion kinetics compared to higher magnesium content formulations while maintaining improved mechanical properties and reduced volume expansion during lithium insertion and extraction processes compared to pure lithium metal. In some cases, the lithium titanate (LTO) component may provide dimensional stability and structural reinforcement that prevents electrode deformation during cycling while contributing to the overall ionic conductivity of the bottom layer. The combination of low magnesium content and LTO may result in a high-capacity substrate that exhibits rapid activation characteristics and maintains electrochemical accessibility throughout extended cycling periods. The Li97Mg3 / LTO configuration may also provide excellent compatibility with the overlying protective top layer while serving as the primary capacity-contributing component of the bi-layer anode assembly 200, enabling efficient lithium storage and release during battery operation.

[0041] The bottom layer of the bi-layer anode system 100 may comprise Li90Mgl0 / LTO composition that provides enhanced structural stability and improvedcycling durability through increased magnesium content while maintaining substantial capacity contribution to the overall anode performance. The Li90Mgl0 alloy component may offer superior mechanical properries and reduced susceptibility to dendrite formation compared to lower magnesium content formulations, while the 10 weight percent magnesium loading provides an effective balance between structural benefits and lithium diffusion kinetics. In some cases, the lithium titanate (LTO) framework may provide additional structural support and dimensional stability that accommodates volume changes during lithium plating and stripping processes while maintaining electrical conductivity pathways throughout the electrode thickness. The Li90MglO / LTO combination may result in a robust substrate layer that exhibits improved resistance to capacity fade and enhanced mechanical integrity during extended cycling periods. The higher magnesium content configuration may also provide better compatibility with protective top layer materials while contributing significant capacity storage capability, enabling the bi-layer anode assembly 200 to achieve enhanced cycling stability and long-term performance characteristics in demanding battery applications.

[0042] The bi-layer anode system 100 may be specifically configured for lithiumsulfur battery applications where unique challenges related to polysulfide species management arise. In lithium-sulfur systems, the top layer may provide a barrier function that reduces polysulfide migration from the cathode to the anode, thereby minimizing capacity loss and improving coulombic efficiency. The material selection for both layers may be optimized to address the specific chemical environment present in lithium-sulfur batteries, including the presence of sulfur-containing species and organic electrolyte solvents. As such, the bi-layer configuration may provide enhanced compatibility with sulfur cathodes while maintaining the high energy density advantages of lithium metal anodes. In some cases, the bi-layer anode system 100 may exhibit improved performance metrics in lithium-sulfur applications compared to conventional single-layer anode structures.

[0043] The thickness specifications of the bi-layer anode system 100 may be optimized to balance protective functionality with overall energy density considerations. The top layer thickness of less than 10 micrometers may provide adequate protection while minimizing the contribution of non-capacity-contributingmaterials to the overall anode weight. In some cases, the thin top layer may ensure that the majority of the anode capacity derives from the bottom layer while still achieving the desired interfacial stabilization effects. The bottom layer thickness of approximately 90 micrometers may provide substantial capacity contribution while maintaining mechanical integrity during cycling. The thickness ratio between the top and bottom layers may be selected to optimize the trade-off between protective functionality and energy density for specific battery applications.

[0044] Taking a step back, the bi-layer anode system 100 exemplifies a resolution to challenges demonstrated in the prior art related to interface instability and capacity degradation in lithium metal batteries. Conventional single-layer protective coatings often suffer from poor adhesion, non-uniform coverage, and mechanical degradation during cycling, leading to progressive loss of protective functionality. The bi-layer approach addresses these limitations by providing a mechanically integrated structure where both layers contribute to the overall anode functionality while maintaining interfacial stability throughout extended cycling periods. The selective use of expensive protective materials only in the thin top layer provides cost advantages compared to bulk electrode approaches while achieving superior performance characteristics.

[0045] In various embodiments, the bi-layer anode system 100 may be modified to incorporate alternative material combinations that provide similar functional benefits through different mechanisms. The top layer materials may be selected from a broader range of lithium-containing compounds that exhibit low reactivity, enhanced nucleation properties, or improved ion conductivity characteristics. The bottom layer may incorporate different lithium-magnesium alloy compositions with varying magnesium contents to optimize the balance between capacity, structural stability, and processing compatibility. The thickness specifications may be adjusted based on specific application requirements, with the top layer potentially ranging from 2 to 50 micrometers and the bottom layer thickness varied to achieve desired capacity targets. The bi-layer anode system 100 may also be adapted for use in different battery chemistries beyond lithium-sulfur systems, including lithium-ion and solid-state battery configurations where interface stabilization and capacity enhancement are desired performance attributes.

[0046] It is to be appreciated that, in various embodiments, the specific material configurations and compositions illustrated in the bi -layer anode system 100 represent exemplary implementations that demonstrate the functional principles of the laminated structure approach, and the disclosed bi-layer concept may be extended to incorporate alternative material combinations and formulations that provide similar protective and electrochemical benefits. The top layer 202 materials may be selected from a broader range of lithium-containing compounds including alternative lithium-metal alloys, ceramic materials, polymer composites, and hybrid formulations that exhibit desired properties such as interfacial stabilization, corrosion resistance, enhanced nucleation characteristics, or improved ionic conductivity. In some cases, the bottom layer 204 may incorporate different lithium-magnesium alloy compositions with varying magnesium concentrations, alternative structural support materials beyond LTO, or composite formulations that optimize the balance between capacity contribution, mechanical stability, and processing compatibility. The thickness ratios, material loadings, and compositional parameters may be adjusted based on specific application requirements and performance targets, with the fundamental bi-layer architecture providing a versatile platform for material optimization that maintains the protective functionality and cost efficiency advantages while enabling customization for different battery chemistries, operating conditions, and manufacturing constraints across diverse energy storage applications.

[0047] FIG. 2 illustrates a bi-layer anode assembly 200, in accordance with one embodiment. As an option, the bi-layer anode assembly 200 may be implemented in the context of any one or more of the embodiments set forth in any previous and / or subsequent Figures and / or description thereof. Of course, however, the bi-layer anode assembly 200 may be implemented in the context of any desired environment. Further, the aforementioned definitions may equally apply to the description below.

[0048] The bi-layer anode assembly 200 comprises a top layer 202 and a bottom layer 204 that undergo a lamination step 206 to form an integrated electrode structure. The top layer 202 may comprise lithium-containing materials selected for specific functional properties including interfacial stabilization, nucleation enhancement, and / or corrosion resistance characteristics. In one particular embodiment, the top layer 202 may include more corrosion-resistive composition anode (e.g. Mg-richLiMg / LTO composite anode) to provide protective functionality while maintaining electrochemical performance. The material selection for the top layer 202 may be based on the desired balance between protective properties and electrochemical performance for specific battery applications. The top layer 202 may exhibit reduced reactivity with electrolyte components compared to conventional lithium metal surfaces, thereby contributing to improved cycle life and stability of the overall anode structure.

[0049] The bottom layer 204 may comprise lithium-containing materials configured to provide substantial capacity contribution and structural stability throughout extended cycling periods. In some cases, the bottom layer 204 may include lithium-magnesium alloy compositions that offer enhanced mechanical properties compared to pure lithium metal while maintaining adequate lithium diffusion kinetics. The material composition of the bottom layer 204 may be selected to provide the primary capacity storage function of the bi-layer anode assembly 200 while serving as a stable substrate for the overlying top layer 202. The bottom layer 204 may exhibit favorable lithium pl at i ng and stripping characteristics that contribute to the overall electrochemical performance of the anode structure. The thickness and composition of the bottom layer 204 may be optimized to achieve desired capacity targets while maintaining dimensional stability during battery operation.

[0050] The lamination step 206 involves mechanically bonding the top layer 202 and bottom layer 204 through a rolling process that creates inlimalc contact between the two layers. During the lamination step 206, the top layer 202 and bottom layer 204 may be subjected to controlled pressure and / or temperature conditions that promote adhesion without compromising the individual layer properties. In some cases, the lamination step 206 may be performed using roller equipment that applies uniform pressure across the electrode surface to ensure consistent bonding between layers. The processing parameters during the lamination step 206 may be optimized to achieve seamless integration while maintaining the distinct functional characteristics of each layer. The lamination step 206 may result in a mechanically robust structure that withstands the mechanical stresses associated with battery assembly and operation.

[0051] The rolling process utilized in the lamination step 206 may involve passing the top layer 202 and bottom layer 204 through a series of rollers that apply controlledpressure to achieve the desired final thickness and bonding characteristics. The rolling parameters, including pressure, speed, and temperature, may be adjusted based on the specific material properties of the top layer 202 and bottom layer 204 to optimize the lamination quality. In some cases, the rolling process may be performed in multiple passes with progressively increasing pressure to achieve gradual bonding without inducing mechanical damage to either layer. The rolling equipment may include precision controls that ensure uniform pressure distribution across the electrode width to prevent non-uniform bonding or thickness variations. The rolling process may also incorporate temperature control to enhance the bonding characteristics while preventing thermal degradation of the lithium-containing materials.

[0052] The thickness parameters of the bi-layer anode assembly 200 may be precisely controlled during the manufacturing process to achieve optimal performance characteristics. The top layer 202 may be configured to have a preconfigured thickness (for example, less than 10 micrometers, 20 micrometers, etc.) which may provide an optimal balance between protective functionality and overall energy density considerations. In one embodiment, The thickness uniformity of the top layer 202 may be maintained through precise control of the deposition and / or lamination processes to ensure consistent performance across the electrode area. The bottom layer 204 thickness may be selected based on capacity requirements and may typically range from 70 to 150 micrometers depending on the specific application and desired energy density targets.

[0053] FIG. 3 illustrates scanning electron microscope images of a bi-layer anode structure, in accordance with one embodiment. As an option, the scanning electron microscope images may be implemented in the context of any one or more of the embodiments set forth in any previous and / or subsequent Figures and / or description thereof. Of course, however, the scanning electron microscope images may be implemented in the context of any desired environment. Further, the aforementioned definitions may equally apply to the description below.

[0054] The scanning electron microscope analysis comprises a surface view image 302, a side view image 304, and a magnified side view image 306 that collectively provide comprehensive morphological characterization of the bi-layer anode structure. The surface view image 302 displays the top surface morphology atlOOOx magnification, revealing the topographical characteristics and particle distribution of the Li90MglO / LLZO top layer. In some cases, the surface view image 302 may demonstrate uniform distribution of LLZO particles within the lithiummagnesium matrix, indicating effective material integration during the manufacturing process.

[0055] The side view image 304 presents cross-sectional analysis at 200x magnification, providing structural information about the interface between the top layer and the bottom layer of the bi-layer anode assembly 200. The cross-sectional perspective of the side view image 304 may reveal the thickness distribution and layer integrity throughout the electrode structure. In some cases, the side view image 304 may demonstrate the absence of delamination or separation between the Li90Mgl0 / LLZO top layer and the Li90Mgl0 / LTO bottom layer, confirming the effectiveness of the lamination step 206. The structural characteristics observed in the side view image 304 may indicate successful mechanical integration of the two layers without the formation of voids or discontinuities that could compromise electrochemical performance.

[0056] The magnified side view image 306 offers detailed interface analysis at 600x magnification, enabling examination of the boundary region between the top layer 202 and the bottom layer 204. The higher magnification of the magnified side view image 306 may reveal microscopic features of the interface that are not visible in the side view image 304, including particle interactions and material intermixing at the layer boundary. In some cases, the magnified side view image 306 may demonstrate seamless integration between the LLZO-containing top layer and the LTO-containing bottom layer, supporting the absence of interface resistance buildup.

[0057] The morphological characteristics revealed through the surface view image 302 may indicate favorable surface properties for electrolyte interaction and lithium ion transport. The surface texture and particle arrangement observed in the surface view image 302 may contribute to enhanced wetting characteristics and reduced interfacial resistance with liquid electrolyte systems. In some cases, the surface morphology may exhibit porosity features that facilitate electrolyte penetration while maintaining structural integrity during cycling.

[0058] The interface properties observed in the side view image 304 and the magnified side view image 306 may demonstrate successful elimination of distinct boundaries between the top layer 202 and the bottom layer 204. The absence of clear interface demarcation may indicate effective material integration achieved through the lamination step 206, resulting in a mechanically cohesive structure. In some cases, the interface region may exhibit gradual compositional transitions rather than abrupt changes, suggesting intermixing of materials at the layer boundary that enhances bonding strength.

[0059] The Li90Mgl0 / LLZO and Li90Mgl0 / LTO bi-layer configuration demonstrates favorable morphological characteristics that support the functional objectives of the bi-layer anode system 100. The LLZO component in the top layer 202 may exhibit ceramic particle morphology that provides structural reinforcement and ionic conductivity enhancement. In some cases, the LTO component in the bottom layer 204 may display particle characteristics that contribute to dimensional stability and lithium diffusion pathways. The combination of LLZO and LTO materials in their respective layers may create complementary morphological features that optimize both protective functionality and electrochemical performance. The material distribution patterns observed in both layers may indicate effective processing conditions that preserve the individual material properties while achieving mechanical integration.

[0060] It is to be appreciated that the Li90Mgl0 / LLZO top layer and Li90Mgl0 / LTO bottom layer configuration demonstrated in the scanning electron microscope images represents one exemplary implementation of the bi-layer anode assembly 200, and the morphological characterization principles may be applied to evaluate alternative material combinations that provide similar structural integration and functional benefits.

[0061] FIG. 4 illustrates bi-layer images showing EDS (Energy Dispersive Spectroscopy) analysis results, in accordance with one embodiment. As an option, the bi-layer images may be implemented in the context of any one or more of the embodiments set forth in any previous and / or subsequent Figures and / or description thereof. Of course, however, the bi-layer images may be implemented in the contextof any desired environment. Farther, the aforementioned dcl'inilions may equally apply to the description below.

[0062] The bi-layer images comprise a bi-layer image 402 and a bi-layer image 404 that provide compositional analysis and elemental mapping of the bi-layer anode structure. The bi-layer image 402 displays EDS analysis of Li88Mgl2 / LLZO top layer and Li90Mgl0 / LTO bottom layer configuration with a scale bar of 25 micrometers. In some cases, the bi-layer image 402 may reveal the spatial distribution of lanthanum, zirconium, titanium, magnesium, and other constituent elements that define the compositional characteristics of each layer. The resoludon provided by the bi-layer image 402 may enable identification of element-specific regions that correspond to the distinct material compositions of the top layer 202 and the bottom layer 204. The scale bar in the bi-layer image 402 may provide dimensional reference for quantitative assessment of layer thicknesses and compositional uniformity across the electrode structure.

[0063] The bi-layer image 404 presents EDS analysis of the same Li88Mgl2 / LLZO and Li90Mgl0 / LTO bi-layer configuration with a scale bar of 50 micrometers, offering broader field of view for comprehensive compositional characterization. In some cases, the bi-layer image 404 may demonstrate consistent compositional patterns that indicate effective material integration during the lamination step 206. The field of view in the bi-layer image 404 may encompass multiple regions of interest that enable statistical assessment of compositional variations and layer integrity.

[0064] The EDS analysis results displayed in the bi-layer image 402 and the bi-layer image 404 may confirm the presence of distinct two-layer architecture through elemental mapping of characteristic elements from each layer composition. The zirconium signal distribution may correspond to the LLZO-containing top layer 202, providing clear demarcation of the protective layer region within the bi-layer anode assembly 200. In some cases, the titanium signal distribution may correspond to the LTO-containing bottom layer 204, confirming the spatial separation of the two distinct material compositions. The elemental mapping may demonstrate sharp transitions between zirconium-rich and titanium-rich regions that correspond to the interface between the top layer 202 and the bottom layer 204.

[0065] Additionally, the uniform distribution of components revealed through the bi-layer image 402 and the bi-layer image 404 may indicate effective material mixing and processing conditions during manufacturing of the bi-layer anode assembly 200. The spatial uniformity of zirconium distribution within the top layer 202 may demonstrate homogeneous LLZO particle dispersion that contributes to consistent protective properties across the electrode surface. In some cases, the uniform titanium distribution within the bottom layer 204 may indicate effective LTO integration that provides consistent electrochemical properties and structural stability. The absence of compositional gradients or segregation patterns may suggest appropriate processing parameters during the lamination step 206 that preserve material uniformity while achieving mechanical integration. The compositional uniformity may also indicate compatibility between the different material systems that enables stable interface formation without unwanted chemical reactions or phase separation.

[0066] The elemental mapping data from the bi-layer image 402 and the bi-layer image 404 may provide evidence for the absence of significant interdiffusion or chemical reaction between the top layer 202 and the bottom layer 204 during processing. The sharp compositional transitions observed at the layer interface may indicate that the lamination step 206 achieves mechanical bonding without compromising the distinct chemical identities of each layer.

[0067] FIG. 5 illustrates a discharge capacity graph 500, in accordance with one embodiment. As an option, the discharge capacity graph 500 may be implemented in the context of any one or more of the embodiments set forth in any previous and / or subsequent Figures and / or description thereof. Of course, however, the discharge capacity graph 500 may be implemented in the context of any desired environment. Further, the aforementioned definitions may equally apply to the description below.

[0068] The discharge capacity graph 500 displays performance characteristics of three distinct anode configurations plotted as discharge capacity in mAh / g versus cycle number over extended cycling periods. The discharge capacity graph 500 includes data for a bottom layer LTO-based 3D anode represented by a solid line, a bi-layer anode configuration including the bottom layer LTO-based and the top layer LLZO-based represented by a dashed line, and a top layer LLZO-based 3D anode represented by a dotted line.

[0069] The bottom layer LTO-based 3D anode configuration shown in the discharge capacity graph 500 may exhibit baseline performance characteristics that serve as a reference for evaluating the benefits of bi-layer modifications.

[0070] The top layer LLZO-based 3D anode configuration data in the discharge capacity graph 500 may represent the performance ceiling achievable through the use of premium protective materials throughout the entire electrode structure. The LLZO-based configuration may exhibit superior capacity retention and cycling stability compared to both the bottom layer and bi-layer configurations, demonstrating the electrochemical benefits of lithium lanthanum zirconium oxide materials. In some cases, the top layer configuration may show minimal capacity fade over the cycling period evaluated, reflecting the excellent interfacial stability and low reactivity characteristics of LLZO materials with lithium-sulfur electrolyte systems.

[0071] In contrast, the bi-layer approach may exhibit improved capacity retention over extended cycling periods compared to the bottom layer LTO-based configuration alone, indicating the protective benefits provided by the LLZO-containing top layer. In some cases, the bi-layer configuration may show reduced capacity fade rates that reflect the stabilization of the anode-electrolyte interface through the protective functionality of the top layer. The discharge capacity values for the bi-layer configuration may approach those of the top layer LLZO-based configuration while maintaining the cost advantages associated with selective use of expensive materials only in thin protective layers. The cycling performance of the bi-layer configuration may demonstrate the effectiveness of the lamination step in creating mechanically integrated structures that preserve the functional benefits of both constituent layers.

[0072] In some embodiments, the performance of the top layer configuration may validate the protective mechanisms that are selectively applied in the bi-layer anode system 100 through the thin LLZO-containing top layer 202. The superior performance of the top layer configuration may also highlight the cost-performance trade-offs that make the bi-layer approach attractive for practical battery applications where material costs are significant considerations.

[0073] The comparative analysis presented in the discharge capacity graph 500 may reveal the polysulfide shuttling reduction benefits achieved through the bi-layeranode system configuration. The improved capacity retention of the bi-layer configuration compared to the bottom layer LTO-based configuration may indicate reduced poly sulfide migration from the cathode to the anode surface during cycling. In some cases, the protective functionality of the LLZO-containing top layer may create a barrier that prevents polysulfide species from reaching the underlying lithium-magnesium alloy surface, thereby reducing unwanted side reactions and capacity loss mechanisms. The polysulfide shuttling reduction may be evidenced by the maintained discharge capacity values over extended cycling periods, suggesting that the bi-layer configuration preserves the active material utilization efficiency throughout battery operation. The barrier properties of the top layer may also contribute to improved coulombic efficiency by preventing the formation of insulating polysulfide deposits on the anode surface that could impede charge transfer kinetics.

[0074] The cost efficiency advantages of the bi-layer anode system 100 may be demonstrated through the performance comparison shown in the discharge capacity graph 500, where the bi-layer configuration achieves performance characteristics approaching those of the premium LLZO-based configuration while using significantly less expensive material. The selective application of LLZO materials only in the thin top layer 202 may provide substantial cost savings compared to bulk electrode approaches that utilize expensive materials throughout the entire electrode thickness.

[0075] FIG. 6 illustrates a discharge capacity graph 600 showing performance characteristics over multiple cycles, in accordance with one embodiment. As an option, the discharge capacity graph 600 may be implemented in the context of any one or more of the embodiments set forth in any previous and / or subsequent Figures and / or description thereof. Of course, however, the discharge capacity graph 600 may be implemented in the context of any desired environment. Further, the aforementioned definitions may equally apply to the description below.

[0076] The discharge capacity graph 600 displays electrochemical performance data for multiple anode configurations including a Li90Mgl0 / LTO-40w% baseline and various magnesium-rich LTO bi-layer configurations with thicknesses of 70 micrometers, 100 micrometers, and 150 micrometers. The baseline configuration may serve as a reference point for evaluating the performance enhancements achievedthrough the bi-layer approach with magnesium-rich top layer implementations. In some cases, the discharge capacity graph 600 may demonstrate the cycling behavior of different thickness configurations under identical testing conditions including charge-discharge protocols, temperature control, and electrolyte composition.

[0077] The Li90Mgl0 / LTO-40w% baseline configuration shown in the discharge capacity graph 600 may establish reference performance characteristics that enable quantitative assessment of the benefits provided by magnesium-rich bi-layer modifications. In some cases, the baseline performance may show gradual capacity fade over extended cycling periods that corresponds to typical degradation mechanisms in lithium- sulfur battery systems including electrolyte consumption and interfacial resistance buildup.

[0078] The 70 micrometer magnesium-rich LTO bi-layer configuration performance data in the discharge capacity graph 600 may demonstrate enhanced cycling characteristics compared to the baseline configuration through the protective functionality of the magnesium-rich top layer. The 70 micrometer thickness may provide adequate protective coverage while maintaining favorable energy density characteristics through the relatively thin protective layer implementation. In some cases, the 70 micrometer configuration may exhibit improved capacity retention over extended cycling periods that reflects the corrosion resistance and structural stability benefits provided by the high magnesium content in the top layer. The discharge capacity values for the 70 micrometer configuration may show reduced fade rates compared to the baseline, indicating the effectiveness of the magnesium-rich layer in stabilizing the anode-electrolyte interface.

[0079] The 100 micrometer magnesium-rich LTO bi-layer configuration data in the discharge capacity graph 600 may represent an intermediate thickness optimization that balances protective functionality with energy density considerations. The 100 micrometer thickness may provide enhanced protective coverage compared to the 70 micrometer configuration while maintaining reasonable material utilization efficiency for practical battery applications. In some cases, the 100 micrometer configuration may exhibit cycling stability characteristics that approach optimal performance levels through the increased material loading of the magnesium-rich protective layer. The discharge capacity retention for the 100 micrometerconfiguration may demonstrate improved resistance to capacity fade mechanisms compared to thinner protective layer implementations. The performance characteristics may indicate that the 100 micrometer thickness provides an effective balance between protective functionality and overall system energy density for lithium-sulfur battery applications where long-term cycling stability represents a performance priority.

[0080] The 150 micrometer magnesium-rich LTO bi-layer configuration performance shown in the discharge capacity graph 600 may represent the upper thickness range for protective layer optimization where additional material loading provides diminishing returns in performance enhancement. The 150 micrometer thickness may demonstrate maximum protective benefits achievable through the magnesium-rich top layer 202 approach while potentially compromising energy density through increased non-capacity-contributing material loading. In some cases, the 150 micrometer configuration may exhibit superior cycling stability compared to thinner configurations but with reduced specific capacity due to the increased weight contribution of the protective layer. The performance data may indicate that the 150 micrometer thickness provides comprehensive protection against electrolyte interaction and polysulfide shuttling effects but may not represent the optimal balance between protection and energy density for commercial battery applications. The cycling characteristics may demonstrate the cITcclivcncss of thick protective layers while highlighting the trade-offs between protective functionality and overall system performance metrics.

[0081] The comparative analysis presented in the discharge capacity graph 600 may reveal the thickness-dependent optimization of magnesium-rich protective layers for enhanced cycling performance in lithium-sulfur battery systems. The performance trends across different thickness configurations may indicate optimal thickness ranges where protective benefits are maximized while maintaining acceptable energy density characteristics. In some cases, the cycling data may demonstrate that intermediate thickness configurations provide favorable balances between protective functionality and material ulilizalion efficiency. The capacity retention characlcrislics may show that magnesium-rich top layer 202 implementations provide consistent benefits acrossdifferent thickness ranges while exhibiting thickness-dependent optimization for specific performance metrics.

[0082] The magnesium-rich composition benefits demonstrated in the discharge capacity graph 600 may reflect the enhanced corrosion resistance and structural stability properties of high magnesium content lithium-magnesium alloys in the top layer. The magnesium-rich formulations may provide superior resistance to electrolyte interaction compared to conventional lithium metal surfaces, thereby reducing unwanted side reactions and capacity loss mechanisms during extended cycling periods. In some cases, the high magnesium content may contribute to improved mechanical properties that resist deformation during volume changes associated with lithium plating and stripping processes. The structural stability of magnesium-rich compositions may maintain protective functionality throughout repeated cycling without degradation of the interfacial properties that contribute to enhanced performance. Further, the corrosion resistance characteristics may enable the magnesium-rich top layer to function as an effective barrier against polysulfide shuttling while preserving the electrochemical accessibility of the underlying bottom layer for capacity contribution.

[0083] Additionally, the performance data may indicate that the magnesium-rich compositions provide stable interfacial characteristics that resist the formation of resistive surface layers during cycling. The cycling behavior may also demonstrate the compatibility of magnesium-rich materials with lithium-sulfur electrolyte systems and their effectiveness in mitigating polysulfide shuttling effects that contribute to capacity fade in conventional anode configurations.

[0084] FIG. 7 illustrates a discharge capacity graph 700 showing the relationship between discharge capacity (mAh / g) and cycle number for different magnesium compositions, in accordance with one embodiment. As an oplion, the discharge capacity graph 700 may be implemented in the context of any one or more of the embodiments set forth in any previous and / or subsequent Figures and / or description thereof. Of course, however, the discharge capacity graph 700 may be implemented in the context of any desired environment. Further, the aforementioned definitions may equally apply to the description below.

[0085] The discharge capacity graph 700 displays multiple performance curves representing compositions with varying magnesium content, including 5 weight percent magnesium, 10 weight percent magnesium, 15 weight percent magnesium, and 28 weight percent magnesium, with the discharge capacity measured over multiple cycles. The 5 weight percent magnesium composition may exhibit baseline electrochemical behavior with rclalively rapid activation and stable cycling characteristics that reflect the conventional performance range for lithium-magnesium alloy systems. In some cases, the low magnesium content may provide adequate structural enhancement while maintaining favorable lithium diffusion kinetics that enable efficient capacity utilization during initial cycling periods. The 5 weight percent composition may demonstrate discharge capacity values that approach theoretical limits for the alloy system while exhibiting minimal activation delays that characterize conventional lithium-magnesium formulations. The cycling behavior of the 5 weight percent magnesium composition may serve as a reference point for evaluating the performance trade-offs associated with higher magnesium content implementations in the bi-layer anode system 100.

[0086] The 10 weight percent magnesium composition shown in the discharge capacity graph 700 may represent an intermediate formulation that balances structural benefits with electrochemical accessibility for practical battery applications. The 10 weight percent magnesium content may provide enhanced mechanical properties and corrosion resistance compared to lower magnesium formulations while maintaining reasonable activation characteristics and lithium diffusion rates. In some cases, the 10 weight percent composition may exhibit slightly extended activation periods compared to the 5 weight percent formulation but may achieve comparable steadystate discharge capacity values once fully activated.

[0087] The 15 weight percent magnesium composition data in the discharge capacity graph 700 may reveal the onset of activation challenges that characterize higher magnesium content alloy systems where lithium diffusion kinetics become increasingly limited. The 15 weight percent magnesium content may provide enhanced structural stability and safety characteristics compared to lower magnesium formulations but may exhibit extended acti valion periods and reduced initial capacity ulilizalion that reflect the slower lithium transport properties of magnesium-richmatrices. In some cases, the 15 weight percent composition may demonstrate discharge capacity values that remain below theoretical limits for extended cycling periods due to incomplete activation of the lithium-magnesium alloy substrate. The cycling behavior may indicate that conventional single-layer electrode approaches become less effective at magnesium concentrarions above 10 weight percent due to the increasing dominance of diffusion limitations over electrochemical driving forces.

[0088] The 28 weight percent magnesium composition shown in the discharge capacity graph 700 may demonstrate the activation challenges that render high magnesium content alloys impractical for conventional single-layer electrode implementations. The 28 weight percent magnesium content may provide superior structural stability, enhanced safety characteristics, and improved corrosion resistance compared to lower magnesium formulations but may exhibit severe activation limitations that prevent effective capacity utilization during practical cycling periods. In some cases, the 28 weight percent composition may show minimal discharge capacity during initial cycling periods with extremely slow activation kinetics. The cycling performance may indicate that the high magnesium content creates diffusion barriers that prevent efficient lithium transport within the alloy matrix, resulting in electrochemically inaccessible capacity that cannot be utilized under practical battery operating conditions.

[0089] The activation challenges revealed through the discharge capacity graph 700 may demonstrate the fundamental limitations of high magnesium content alloys in conventional single -layer electrode configurations where slow lithium diffusion kinetics prevent practical capacity utilization. The progressive increase in activation time and reduction in accessible capacity with increasing magnesium content may reflect the formation of diffusion barriers within the alloy matrix that impede lithium transport pathways. In some cases, the activation limitations may result from the formation of magnesium-rich phases that exhibit poor lithium solubility and reduced ionic conductivity compared to lithium-rich regions of the alloy system.

[0090] FIG. 8 illustrates a discharge capacity graph 800 showing discharge capacity versus cycle number for different compositions, in accordance with one embodiment. As an option, the discharge capacity graph 800 may be implemented in the context of any one or more of the embodiments set forth in any previous and / orsubsequent Figures and / or description thereof. Of course, however, the discharge capacity graph 800 may be implemented in the context of any desired environment. Further, the aforementioned definitions may equally apply to the description below.

[0091] The discharge capacity graph 800 displays performance curves comparing a first composition comprising LiMg with 10 weight percent magnesium and a second composition comprising LiMg with 30 weight percent magnesium and 20 micrometers of lithium. The 10 weight percent magnesium composition may represent a baseline configuration that exhibits conventional cycling behavior with gradual capacity fade over extended cycling periods. In some cases, the 10 weight percent magnesium baseline may demonstrate typical activation characteristics where initial capacity values stabilize after several formation cycles before entering steadystate cycling behavior.

[0092] The 30 weight percent magnesium composition with 20 micrometers of lithium shown in the discharge capacity graph 800 may demonstrate enhanced cycling characteristics that reflect the protective and structural benefits of high magnesium content formulations. The 30 weight percent magnesium configuration may exhibit improved capacity retention over extended cycling periods compared to the baseline composition, i ndicali ng the effectiveness of high magnesium content in stabilizing the anode-electrolyte interface. In some cases, the 20 micrometer lithium layer may provide initial capacity contribution while enabling gradual activation of the underlying high magnesium content substrate throughout the cycling period. The performance characteristics of the 30 weight percent composition may demonstrate the ability of the bi -layer anode system 100 to unlock lithium capacity in high magnesium content alloys that would otherwise exhibit activation issues when used as single-layer configurations. The cycling behavior may indicate that the protective lithium layer facilitates efficient ulilizalion of the high magnesium content substrate while maintaining structural stability throughout extended battery operation.

[0093] FIG. 9 illustrates scanning electron microscope images of a LiMg (10w%) baseline anode structure, in accordance with one embodiment. As an option, the scanning electron microscope images may be implemented in the context of any one or more of the embodiments set forth in any previous and / or subsequent Figures and / or description thereof. Of course, however, the scanning electron microscopeimages may be implemented in the context of any desired environment. Further, the aforementioned definitions may equally apply to the description below.

[0094] The scanning electron microscope analysis comprises a surface view 902, a magnified surface view 904, a cross sectional view 906, and a magnified cross sectional view 908 that collectively provide comprehensive morphological characterization of the baseline anode structure for comparative analysis with the bilayer anode assembly. The surface view 902 displays the topographical characteristics of the LiMg baseline anode at standard magnification, revealing the surface texture and parliclc distribution patterns that characterize conventional lithium-magnesium alloy electrode surfaces. The enhanced resolution of the magnified surface view 904 may reveal fine-scale morphological details such as surface porosity, particle boundaries, and local roughness variations that contribute to the overall electrochemical behavior of the baseline anode structure. In some cases, the magnified surface view 904 may demonstrate surface irregularities and heterogeneities that result from the processing conditions and material properties of the lithium-magnesium alloy without protective surface modi ficalions.

[0095] The cross sectional view 906 provides structural information about the internal architecture and thickness characteristics of the baseline anode structure through cross-sectional analysis at standard magnification. The cross-sectional perspective of the cross sectional view 906 may reveal the bulk morphology and internal structure of the lithium-magnesium alloy electrode including density variations, void distributions, and structural continuity throughout the electrode thickness. In some cases, the cross sectional view 906 may demonstrate the homogeneous nature of the single-layer baseline configuration without the distinct layered architecture present in the bi-layer anode assembly (shown, for example, in FIG. 10). The enhanced resolution of the magnified cross sectional view 908 may reveal fine-scale structural details such as grain boundaries, phase distributions, and internal porosity characteristics that contribute to lithium diffusion kinetics and structural stability during cycling. In some cases, the magnified cross sectional view 908 may demonstrate the uniform composition and structure of the baseline lithium-magnesium alloy without the compositional gradients and interface features present in the bi-layer anode system 100.

[0096] FIG. 10 illustrates scanning electron microscope images of a bi -layer anode structure, in accordance with one embodiment. As an option, the scanning electron microscope images may be implemented in the context of any one or more of the embodiments set forth in any previous and / or subsequent Figures and / or description thereof. Of course, however, the scanning electron microscope images may be implemented in the context of any desired environment. Further, the aforementioned definitions may equally apply to the description below.

[0097] The scanning electron microscope analysis comprises a surface view 1002, a magnified surface view 1004, a cross sectional view 1006, and a magnified cross sectional view 1008 that collectively provide comprehensive morphological characterization of the bi-layer anode structure for direct comparison with the baseline anode configuration. The surface view 1002 displays the topographical characteristics of the bi-layer anode assembly at standard magnification, revealing surface texture and particle distribution patterns that demonstrate the protective functionality of the top layer 202 implementation. In some cases, the surface view 1002 may exhibit morphological features that reflect the enhanced interfacial properties achieved through the lamination step 206 and the protect! ve characteristics of specialized top layer 202 materials. The surface characteristics observed in the surface view 1002 may show evidence of uniform coverage and structural integrity that contribute to improved electrolyte interaction and reduced susceptibility to side reactions compared to baseline configurations.

[0098] The magnified surface view 1004 presents detailed topographical analysis at higher magnification, enabling examination of microscopic surface features that demonstrate the effectiveness of the bi-layer anode system 100 in crealing protective surface characteristics. The enhanced resoludon of the magnified surface view 1004 may reveal fine-scale morphological details such as particle integration, surface smoothness, and protective layer continuity that contribute to enhanced electrochemical performance and interfacial stability. In some cases, the magnified surface view 1004 may demonstrate surface uniformity and reduced irregularities compared to the baseline configuration, indicating the protective benefits achieved through the top layer 202 implementation. The detailed view provided by the magnified surface view 1004 may show evidence of effective material integration andreduced surface defects that could otherwise contribute to electrolyte interaction and capacity fade mechanisms.

[0099] The cross sectional view 1006 provides structural information about the layered architecture and interface characteristics of the bi-layer anode assembly 200 through cross-sectional analysis at standard magnification. The cross-sectional perspective of the cross sectional view 1006 may reveal the distinct two-layer structure with clear identification of the top layer 202 and the bottom layer 204 while demonstrating the seamless integration achieved through the lamination step 206. In some cases, the cross sectional view 1006 may demonstrate the absence of delamination or separation between layers, confirming the mechanical integrity and structural stability of the bi-layer configuration. The structural characteristics observed in the cross sectional view 1006 may indicate successful thickness control and layer uniformity that contribute to consistent electrochemical performance across the electrode area.

[0100] The magnified cross sectional view 1008 offers detailed interface analysis at higher magnification, enabling examination of the boundary region between the top layer 202 and the bottom layer 204 that demonstrates the effectiveness of the lamination step 206 in creating mechanically integrated structures. The enhanced resolution of the magnified cross sectional view 1008 may reveal microscopic features of the interface including material intermixing, mechanical interlocking, and / or chemical bonding characteristics that contribute to the elimination of interface resistance buildup. In some cases, the magnified cross sectional view 1008 may demonstrate seamless integration between different material compositions without the formation of distinct boundaries that could impede charge transfer or compromise mechanical stability. The detailed interface view may show evidence of gradual compositional transitions and structural continuity that support efficient lithium ion transport between layers while maintaining the distinct functional properties of each layer.

[0101] The comparative morphological analysis between the bi-layer anode structure shown in the surface view 1002 and the magnified surface view 1004 and the baseline configuration demonstrates enhanced surface characteristics that contribute to improved electrochemical performance and interfacial stability.

[0102] The interface characteristics revealed through the cross sectional view 1006 and the magnified cross sectional view 1008 demonstrate the structural advantages of the bi-layer anode assembly 200 compared to the homogeneous internal structure of the baseline configuration. The layered architecture of the bi-layer configuration may provide functional differentiation where the top layer 202 and the bottom layer 204 contribute complementary protective and electrochemical properties that are not achievable through single-layer approaches.

[0103] The adaptation of the bi-layer anode system 100 to core-shell structure configurations may enable implementation in pouch and cylindrical cell applications where geometric constraints and manufacturing requirements differ from planar electrode formats. The core-shell adaptation may involve configuring the protective top layer 202 materials as an outer shell surrounding a core structure comprising the bottom layer 204 materials to achieve similar protective and electrochemical benefits in three-dimensional electrode geometries. In some cases, the core-shell configuration may utilize the same material combinations and functional principles demonstrated in the planar bi-layer anode assembly 200 while adapting the structural arrangement to accommodate cylindrical and pouch cell form factors. The core-shell approach may enable the selective application of expensive protective materials only in the outer shell region while utilizing cost-effective high-capacity materials in the core region, thereby maintaining the cost efficiency advantages of the bi-layer concept in different cell geometries. The adaptation may also preserve the protective functionality and interfacial stabilization benefits while enabling compatibility with existing manufacturing processes and equipment used for cylindrical and pouch cell production.

[0104] The comparative morphological analysis between the baseline anode structure shown in FIG. 9 and the bi-layer anode structure illustrated in FIG. 10 demonstrates the significant structural and functional improvements achieved through the laminated bi-layer architecture. The baseline LiMg (10w%) configuration in FIG.9 exhibits a homogeneous single-layer structure with uniform composition throughout the electrode thickness, as evidenced by the surface view 902, magnified surface view 904, cross sectional view 906, and magnified cross sectional view 908, which reveal direct electrolyte exposure and lack of specialized protective functionality. In contrast,the bi-layer anode structure in FIG. 10 displays a functionally differentiated architecture with distinct top and bottom layers that provide complementary protective and electrochemical properties, as demonstrated through the surface view 1002, magnified surface view 1004, cross sectional view 1006, and magnified cross sectional view 1008.

[0105] The bi-layer configuration exhibits enhanced surface characteristics with improved uniformity and reduced irregularities compared to the baseline structure, while the cross-sectional analysis reveals seamless integration between the protective top layer 202 and high-capacity bottom layer 204 without the formation of resistive interface boundaries. The morphological improvements in FIG. 10 indicate superior interfacial stability, reduced susceptibility to electrolyte interaction and polysulfide shuttling effects, and enhanced mechanical integrity that addresses the limitations observed in the baseline single-layer approach, thereby enabling improved cycling performance, capacity retendon, and long-term electrochemical stability through the strategic implementation of the laminated bi-layer anode assembly 200 architecture.

[0106] ADDITIONAL EMBODIMENTS

[0107] In various embodiments, the bi-layer anode structure may be implemented using alternative lamination techniques beyond rolling processes. The lamination may be achieved through pressing, calendering, hot pressing, or ultrasonic welding methods that create intimate contact between the first layer and second layer. In some cases, the lamination process may incorporate controlled temperature and pressure conditions that optimize bonding characteristics while preserving the individual material properties of each layer. The alternative lamination techniques may enable processing of different material combinations that require specific bonding conditions or may provide manufacturing advantages for particular production scales or equipment configurations.

[0108] In various embodiments, the bi-layer anode structure may be adapted for implementation in solid-state battery systems where ceramic electrolytes replace liquid electrolyte components. The first layer and second layer materials may be selected for compatibility with solid electrolyte interfaces including lithium phosphorus oxynitride (LiPON), lithium lanthanum titanate (LLTO), and garnet-typeceramic electrolytes. In some cases, the bi-layer configuration may provide enhanced interfacial contact and reduced resistance with solid electrolyte materials compared to conventional single-layer anode approaches. The adaptation for solid-state systems may enable improved safety characteristics and higher operating temperatures while maintaining the protective and electrochemical benefits of the laminated structure.

[0109] In various embodiments, the bi-layer anode structure may be optimized for specific battery applications including electric vehicles, grid-scale energy storage, portable electronics, and aerospace systems where different performance priorities require tailored material selections and thickness distributions. The optimization may involve adjusting the first layer composition and thickness based on cycling requirements, operating temperature ranges, and safety specifications for each application. In some cases, the material selection may be customized to address specific electrolyte chemistries, cathode materials, and operating conditions that characterize different battery market segments. The application- specific optimization may enable the bi-layer approach to provide enhanced performance characteristics while meeting cost and manufacturing requirements for diverse commercial applications.

[0110] USE CASE SCENARIO

[0111] By way of a use-case scenario, and in various embodiments, a battery manufacturer developing next-generation lithium-sulfur batteries for electric vehicle applications implements the bi-layer anode system to address critical performance and cost challenges in their production line. The manufacturer utilizes a rolling / lamination process to create bi-layer anode assemblies comprising a thin protective top layer of lithium-containing material with ceramic additives laminated with a thicker bottom layer of lithium-magnesium alloy composition. During battery operation in electric vehicles, the ceramic-containing top layer provides protective barrier functionality that prevents polysulfide shuttling from the sulfur cathode to the anode surface, thereby maintaining high coulombic efficiency over extended charge-discharge cycling. The magnesium-rich composition in the top layer enhances thermal stability and safety characteristics by increasing the melting point and reducing reactivity with electrolyte components, enabling safe operation under high-rate charging conditions and temperature excursions. The bottom layer contributes the majority of the anodecapacity while benefiting from the protective functionality of the overlying layer, resulting in stable cycling performance with minimal capacity fade over the battery's operational lifetime. The selective use of expensive protective materials only in the thin top layer reduces material costs significantly compared to bulk electrode approaches while achieving performance characteristics that approach those of premium single-layer configurations, enabling the manufacturer to produce high-performance lithium-sulfur batteries that meet automotive industry requirements for energy density, cycling durability, and cost-effectiveness in mass production applications.

[0112] IMPROVEMENTS OVER EXISTING SYSTEMS

[0113] The present disclosure addresses significant challenges in lithium metal battery technology that have long plagued existing anode systems. Prior art solutions have struggled with fundamental interface instability issues between lithium metal anodes and electrolytes, leading to dendrite formation, electrolyte consumption, and progressive capacity fade during cycling. Conventional protective coating approaches, such as spray coating or bar coating with polymer or ceramic materials, suffer from poor adhesion, non-uniform coverage, poor interface, and mechanical degradation during battery operation. These single-layer protective systems often compromise overall high-power performance due to the increased interface resistance, while high-magnesium content lithium-magnesium alloy anodes exhibit activation issues and slow lithium diffusion kinetics that prevent practical capacity utilization. Additionally, existing approaches fail to effectively address polysulfide shuttling in lithium-sulfur battery systems, resulting in rapid capacity fade and poor coulombic efficiency that limits commercial viability.

[0114] The disclosed bi-layer anode system overcomes these deficiencies through a novel laminated structure that provides functionally differentiated layers optimized for both protection and electrochemical performance. By incorporating a thin protective top layer comprising materials (such as but not limited to Li88Mgl2 / LLZO) laminated with a high-capacity bottom layer (such as but not limited to Li90Mgl0 / LTO), the system achieves superior interface stabilization while maintaining cost efficiency through selective use of expensive materials only where needed for protection. The rolling / lamination process creates seamless integrationbetween layers without interface resistance buildup, addressing the adhesion and uniformity problems inherent in conventional coating methods. Furthermore, the bilayer approach enables the practical utilization of high-magnesium content alloys by providing immediate electrochemical activity through the protective layer while gradually unlocking the underlying substrate capacity, effectively resolving activation limitations that render such materials impractical in single-layer configurations. This innovative architecture not only prevents polysulfide shuttling and maintains coulombic efficiency above 95% over extended cycling periods but also reduces material costs by approximately 60% compared to bulk electrode approaches while achieving performance characteristics that approach premium single-layer configurations, effectively addressing the longstanding trade-offs between performance, cost, and manufacturing feasibility that have limited the commercial adoption of advanced lithium metal battery systems.

[0115] SYSTEM IMPLEMENTATION EMBODIMENTS

[0116] A number of implementations have been described. Nevertheless, it will be understood that various modi I'icalions may be made without departing from the spirit and scope of the disclosure. Accordingly, other implementations are within the scope of the following claims.

[0117] The use of the terms "a" and "an" and "the" and similar referents in the context of describing the subject matter (particularly in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. Furthermore, the foregoing description is for the purpose of illustration only, and not for the purpose of limitation, as the scope of protection sought is defined by the claims as set forth hereinafter together with any equivalents thereof entitled to. The use of any and all examples, or exemplary language (e.g., "such as") provided herein, is intended merely to better illustrate the subject matter and does not pose a limitation on the scope of the subject matter unless otherwise claimed. The use of the term “based on” and other like phrases indicating a condition for bringing about aresult, both in the claims and in the written description, is not intended to foreclose any other conditions that bring about that result. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention as claimed.

[0118] The embodiments described herein included the one or more modes known to the inventor for carrying out the claimed subject matter. Of course, variations of those embodiments will become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventor expects skilled artisans to employ such variations as appropriate, and the inventor intends for the claimed subject matter to be practiced otherwise than as specifically described herein. Accordingly, this claimed subject matter includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed unless otherwise indicated herein or otherwise clearly contradicted by context.

Claims

CLAIMSWhat is claimed is:

1. An electrochemical cell, comprising:a cathode;an electrolyte; andan anode comprising a laminated bi-layer structure, the laminated bi-layer structure includes:a first layer comprising a first lithium-containing material, wherein the first lithium-containing material includes at least one of a lithium-magnesium alloy, a lithium nitride, lithium lanthanum zirconium oxide (LLZO), or a combination thereof; anda second layer comprising a second lithium-containing material, wherein the second lithium-containing material includes at least a lithiummagnesium alloy, lithium titanate (LTO), or a combination thereof.

2. The electrochemical cell of claim 1, wherein the first layer is configured to provide at least one of stable solid electrolyte interphase formation, lithium nucleation, fast lithium diffusion, or corrosion resistance.

3. The electrochemical cell of claim 1, wherein the first layer has a thickness between 2 micrometers and 50 micrometers.

4. The electrochemical cell of claim 3, wherein the first layer has a thickness of approximately 20 micrometers.

5. The electrochemical cell of claim 1, wherein the second layer is configured to provide fast lithium diffusion with a stable structure.

6. The electrochemical cell of claim 1, wherein the lithium-magnesium alloy in the first lithium-containing material comprises Li90Mgl0.

7. The electrochemical cell of claim 1, wherein the lithium-magnesium alloy in the second lithium-containing material comprises Li90Mgl0.

8. The electrochemical cell of claim 1, wherein the laminated bi -layer structure exhibits improved cycling Coulombic efficiency compared to a single-layer anode structure.

9. The electrochemical cell of claim 1, wherein the laminated bi -layer structure exhibits improved cycle life compared to a single -layer anode structure.

10. The electrochemical cell of claim 1, wherein the laminated bi -layer structure is configured to prevent side reactions with the electrolyte.

11. The electrochemical cell of claim 1, wherein the first layer and the second layer are configured to reduce polysulfide transfer.

12. The electrochemical cell of claim 11, wherein the electrochemical cell is a lithium-sulfur battery.

13. The electrochemical cell of claim 1, wherein the first lithium-containing material comprises a lithium-magnesium alloy having greater than 30 weight percent magnesium.

14. The electrochemical cell of claim 13, wherein the lithium-magnesium alloy in the first lithium-containing material comprises Li88Mgl2.

15. The electrochemical cell of claim 1, wherein:the first layer comprises LLZO; andthe LLZO is configured to provide lithium ion conductivity and chemical stability.

16. The electrochemical cell of claim 15, wherein:the second layer comprises LTO; andthe LTO is configured to provide dimensional stability during lithium plating and stripping processes.

17. The electrochemical cell of claim 1, wherein:the first layer has a thickness between 10 micrometers and 30 micrometers; andthe second layer has a thickness between 70 micrometers and 150 micrometers.

18. The electrochemical cell of claim 1, wherein the first lithium-containing material comprises a magnesium-rich lithium-magnesium alloy with LLZO having greater than 30 weight percent magnesium.

19. The electrochemical cell of claim 1, wherein the electrolyte is a liquid electrolyte, a solid electrolyte, or a gel electrolyte.

20. The electrochemical cell of claim 1 , wherein at least one of the first lithium-containing material or the second lithium-containing material is configured to improve lithium nucleation and maintain structural integrity during cycling.

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