Electrochemical sample loading platform

Abstract

The invention belongs to the technical field of electrochemical in-situ characterization, and particularly relates to an electrochemical sample carrying table for near-normal-pressure photoelectron spectroscopy analysis. The sample carrying table comprises a base, a sealing shell fixed on the base, an electrode assembly packaged in the shell and a packaging layer covering a key area of the electrode assembly. The encapsulation layer allows the excitation rays to pass through and the generated photoelectrons to pass through, while blocking the volatilization of the liquid electrolyte. The housing is provided with an incidence channel for the incidence of excitation rays, and the packaging layer corresponds to the channel. The core is that the packaging layer is configured to realize two key functions at the same time: 1, the dissipation of volatile liquid electrolyte is effectively blocked, and a stable micro-area liquid phase environment is maintained on the surface of the electrode; and secondly, excitation rays are allowed to penetrate and generated characteristic photoelectrons are ensured to efficiently escape, so that in-situ and real-time spectroscopic detection of an electrode-electrolyte interface is realized.

Description

Technical Field

[0001] This invention relates to the field of electrochemical in-situ characterization technology, and in particular to an electrochemical sample stage. Background Technology

[0002] In the study of secondary batteries (including metal-ion batteries, flow batteries, and solid-state batteries), the dynamic physicochemical processes at the electrode-electrolyte interface (such as the formation and evolution of SEI / CEI) directly determine the battery's performance and lifespan. In-situ surface analysis techniques, especially X-ray photoelectron spectroscopy (XPS), are key methods for revealing these interfacial reaction mechanisms. However, traditional XPS requires an ultra-high vacuum environment (UHV, <10⁻⁶ Å). -9 The mbar is completely incompatible with real battery systems containing volatile liquid electrolytes, forcing research to rely on non-in-situ disassembly analysis, inevitably introducing artifacts such as air exposure and component decomposition, and failing to capture the dynamic information of the interface under working conditions.

[0003] In recent years, near-atmospheric pressure XPS ((N)AP-XPS) has increased the detection pressure to 2-30 mbar, enabling in-situ studies of solid-gas and even solid-liquid interface reactions. However, when applied to secondary batteries, a fundamental challenge lies in how to stably introduce volatile liquid electrolytes into the detection region. Existing solutions typically face a dilemma: if the liquid is not effectively sealed, its vapor will evaporate rapidly, disrupting the vacuum of the experimental chamber, interfering with ion transport paths, and altering local concentrations, leading to detection failure; if traditional physical encapsulation methods (such as thick-layer sealing or metal encapsulation) are used, although evaporation can be suppressed, their inherent opacity or excessive thickness will severely hinder or even completely block the escape of photoelectrons. Due to the extremely short inelastic mean free path of photoelectrons in matter (usually at the nanoscale), this "signal barrier" causes photoelectron signals from key interfaces to be significantly attenuated or undetectable, severely impairing the quality of spectral data and the correlation accuracy of in-situ electrochemical tests.

[0004] Therefore, developing an electrochemical sample stage specifically for in-situ NAP-XPS studies of batteries is crucial. The core design goal of this stage is to resolve the contradiction between "effective sealing" and "signal transparency": it must be able to construct a stable micro-region of liquid electrolyte environment, effectively preventing its evaporation into the vacuum chamber; simultaneously, its sealing interface must be thin enough and highly permeable to X-rays and photoelectrons, ensuring that characteristic photoelectrons from the electrode-electrolyte interface can escape efficiently and be received by the detector. Achieving this goal is key to moving the accurate, dynamic, in-situ characterization of real battery systems containing liquid electrolytes under near-ambient pressure from concept to practice. Summary of the Invention

[0005] The purpose of this invention is to provide an electrochemical sample stage for (near) ambient pressure spectroscopic analysis (such as NAP-XPS). This sample stage can effectively block volatile liquid electrolytes while ensuring sufficient photoelectron signal flux, thereby achieving accurate and stable in-situ characterization of the electrode-electrolyte interface of secondary batteries containing liquid electrolytes.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] An electrochemical sample stage, comprising:

[0008] The base provides mechanical support and interfaces with the external spectrometer sample stage.

[0009] A sealed housing is fixed to the base and together with the base forms an internal cavity. An incident channel for incident X-rays to pass through is provided on the sealed housing.

[0010] An electrode assembly, encapsulated within the internal cavity of the sealed housing, is used to form an in-situ cell capable of electrochemical reactions, comprising at least one working electrode and a counter electrode.

[0011] An encapsulation layer covers the area of ​​the electrode assembly that carries the liquid electrolyte and forms a seal with the sealed housing, confining the liquid electrolyte within a micro-region between the electrode surface and the encapsulation layer; the material and thickness of the encapsulation layer are configured to allow X-rays to penetrate effectively to excite photoelectrons, while allowing the generated photoelectrons to escape to an external detector, and effectively blocking the macroscopic dissipation and volatilization of the liquid electrolyte components.

[0012] As an optional implementation, the working electrode of the electrode assembly is a three-dimensional or porous electrode loaded with electrochemically active materials. Preferably, the surface of the working electrode has a finely machined flat region with a surface roughness treated to the submicron or nanometer level. This flat region serves to support the liquid electrolyte and adhere tightly to the encapsulation layer to form a uniform and stable liquid-solid-gas (vacuum) three-phase interface, minimizing photoelectron signal attenuation caused by interface irregularities.

[0013] As an optional implementation, the electrode assembly also includes a reference electrode, which is integrated together with the working electrode and the counter electrode in a sealed housing to form a three-electrode system for accurately monitoring and controlling the potential of the working electrode during operation.

[0014] As an optional implementation, in order to ensure the stable distribution of the liquid electrolyte during the test and to avoid uneven liquid film or flow due to gravity, the main surfaces of each electrode in the electrode assembly are set to be approximately parallel to the bottom surface of the base, and their levelness deviation is controlled within a certain range.

[0015] As an optional implementation, the electrical connection of the electrode assembly is achieved through a vacuum-compatible lead structure. Specifically, it includes a working electrode adapter and a counter electrode adapter, which are disposed on the base and insulated from each other. The working electrode and the counter electrode are respectively connected to their corresponding adapters via sealed wires passing through the housing. The adapters may take the form of spring pins, pads, or sockets, for coupling with corresponding electrical contacts or vacuum feedthrough devices on an external spectrometer sample stage, thereby leading the electrical signal to an external electrochemical workstation. Insulating elements are provided between the adapters and between the adapters and the base to prevent short circuits.

[0016] As an optional implementation, the encapsulation layer is made of a material with high X-ray and photoelectron transmittance and low liquid electrolyte vapor permeability. This encapsulation layer can be a dense or functional thin film with nanoscale controllable pores. Its thickness is typically between a few nanometers and several hundred nanometers, preferably within the order of the inelastic mean free path of photoelectrons (1 nm to 100 nm), to maximize the escape probability of photoelectrons while ensuring mechanical seal strength. Exemplary materials include, but are not limited to, polymer films (such as polyimide, silazane), low-dimensional layered materials (such as graphene and its derivatives, hexagonal boron nitride, etc.), metal-organic framework (MOF) films, or inorganic ceramic films.

[0017] As an optional implementation, the sealing housing includes a main housing fixed to the base and a top cover that is detachably or fixedly connected. The injection channel is formed on the top cover. The inner side of the top cover may be designed with a positioning structure for pressing and positioning the edge of the encapsulation layer to ensure sealing reliability. The housing material is preferably an insulating material with good vacuum compatibility, low gas leakage rate, and certain mechanical strength, such as specific engineering plastics, ceramics, or composite materials.

[0018] Beneficial effects:

[0019] The electrochemical sample stage provided by this invention, through an innovative micro-region sealing design, creates a stable physical environment for volatile liquid electrolytes, successfully solving the core problem of their easy volatility and difficulty in fixation in near-ambient pressure analytical chambers. This design ingeniously balances the contradiction between "sealing" and "transmission": the encapsulation layer is sufficient to block the macroscopic volatilization of the liquid electrolyte, maintaining the stability of the local chemical environment; at the same time, it is thin and transparent enough to allow X-ray incidence and efficient escape of excited photoelectrons, thereby ensuring the intensity and quality of key spectral signals from the electrode-electrolyte interface.

[0020] By combining this sample stage with a near-ambient pressure X-ray photoelectron spectroscopy (XPS) instrument and an electrochemical workstation, a complete in-situ analysis system can be constructed. This system enables end-to-end operation, from battery sealing and assembly, contamination-free transport to real-time electrochemical-spectral analysis. It truly achieves in-situ, real-time observation of the dynamic formation and evolution of key interfacial phases, such as the solid electrolyte interface, in the working state of secondary batteries. This provides an irreplaceable and powerful tool for a deeper understanding of battery reaction mechanisms and the optimization of electrolyte and electrode materials. The sample stage design is modular and highly compatible, making it easy to apply to various in-situ characterization studies involving complex gas-liquid-solid interfaces. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the electrochemical sample stage provided in an embodiment of the present invention;

[0022] Figure 2 This is a first-view exploded view of the electrochemical sample stage provided in an embodiment of the present invention;

[0023] Figure 3 This is a split view of the electrochemical sample stage provided in an embodiment of the present invention from a second perspective.

[0024] In the picture:

[0025] 1. Base;

[0026] 2. Sealed housing; 21. Main housing; 22. Top cover; 221. Injection channel;

[0027] 3. Electrode assembly; 31. Working electrode; 32. Counter electrode; 33. Reference electrode; 34. Diaphragm; 35. Support platform; 36. Working electrode wiring; 37. Counter electrode wiring; 38. Reference electrode wire;

[0028] 4. Encapsulation layer; 5. Gasket; 6. Working electrode adapter; 7. Counter electrode adapter; 8. Fastener; 8a. Screw; 8b. Nut. Detailed Implementation

[0029] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0030] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0031] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0032] In the description of this embodiment, the terms "upper," "lower," "left," and "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0033] Surface analysis techniques, besides X-ray photoelectron spectroscopy, include other spectral methods such as ultraviolet photoelectron spectroscopy, reflected photoelectron spectroscopy, and Auger electron spectroscopy. Among these, X-ray photoelectron spectroscopy (XPS) is crucial for studying the chemical state evolution (such as valence state changes and interfacial reaction mechanisms) at the electrode / electrolyte interface of batteries. Traditional XPS requires a high vacuum environment (<10). -9 The vacuum level is mbar, and liquid electrolytes are prone to volatilization under these conditions; near-ambient pressure XPS (NAP-XPS) can alleviate vacuum limitations, but liquid electrolytes will still volatilize under this vacuum level; and traditional packaging methods will block photoelectronic signals.

[0034] Currently, existing electrochemical sample stages have two major limitations: First, they are limited to solid electrolytes / ionic liquid electrolytes and cannot be compatible with liquid electrolytes to solve the volatilization problem of liquid electrolytes. Second, when using an inclined or vertical sample stage, the liquid electrolyte flows under the action of gravity, which interferes with the stability of the electrode / electrolyte interface and introduces test errors.

[0035] like Figures 1 to 3 As shown, this embodiment provides an electrochemical sample stage, which includes a base 1, a sealed housing 2, an electrode assembly 3, and an encapsulation layer 4. The base 1 provides a mechanical mounting reference, and the sealed housing 2 is fixed on the base 1. The sealed housing 2 and the base 1 together define a sealed inner cavity, and an incident channel 221 is provided on the sealed housing 2. The electrode assembly 3 is sealed in the sealed inner cavity and includes at least one working electrode 31 and one counter electrode 32. The working electrode 31 has a surface for holding liquid electrolyte. The edge region of the encapsulation layer 4 forms a seal with the sealed housing 2 and covers the surface of the working electrode 31, thereby forming a closed micro-region for containing liquid electrolyte between the encapsulation layer 4 and the surface of the working electrode 31. In the corresponding region of the incident channel 221, the material and thickness of the encapsulation layer 4 are selected to allow excitation rays to penetrate and act on the electrode assembly 3, and to allow photoelectrons generated by the excitation to escape to the outside of the sealed inner cavity, while blocking the macroscopic volatilization of liquid electrolyte.

[0036] Through an innovative micro-region sealing design, a stable environment for volatile liquid electrolytes is created in physical space, successfully solving the core problem of their easy volatility and difficulty in immobilization in near-ambient pressure analytical chambers. This design ingeniously balances the contradiction between "sealing" and "transmission": the encapsulation layer 4 is sufficient to block the macroscopic volatilization of liquid electrolytes and maintain the stability of the local chemical environment; at the same time, it is thin and transparent enough to allow X-rays to enter and the photoelectrolytes to escape efficiently, thereby ensuring the intensity and quality of key spectral signals from the electrode-electrolyte interface.

[0037] The electrochemical sample stage is applicable to X-ray photoelectron spectroscopy, as well as other energy spectra such as ultraviolet photoelectron spectroscopy, reflected photoelectron spectroscopy, and Auger electron spectroscopy. The specific usage of the electrochemical sample stage is the same. This embodiment takes X-ray photoelectron spectroscopy as an example, using X-rays as the radiation source. The X-rays enter through the incident channel 221 on the sealed housing 2, penetrate the encapsulation layer 4, act on the electrode assembly 3, and excite photoelectrons. If applied to other energy spectra, other radiation sources are required, such as ultraviolet light or high-energy electron beams. The targets of electrochemical testing include, but are not limited to, galvanic cells, electrolytic cells, solar cells, capacitors, and electrocatalysts.

[0038] This electrochemical sample stage, when used in conjunction with a near-ambient pressure X-ray photoelectron spectroscopy (XPS) instrument and an electrochemical workstation, can form a complete in-situ analysis system. This system enables end-to-end operation, from battery sealing and assembly, contamination-free transport to real-time electrochemical-spectral analysis. It truly achieves in-situ, real-time observation of the dynamic formation and evolution of key interfacial phases such as the solid electrolyte interface (SEI) in the working state of secondary batteries, providing an irreplaceable and powerful tool for a deeper understanding of battery reaction mechanisms and optimization of electrolyte and electrode materials. The electrochemical sample stage is modular and highly compatible, making it easy to apply to various in-situ characterization studies involving complex gas-liquid-solid interfaces.

[0039] In this embodiment, the electrochemical workstation and the glove box-vacuum interconnection system are integrated. The sample stage base 1 can be connected to this integrated system via a standardized interface, thereby achieving inert atmosphere protection throughout the entire process of sample preparation, packaging, and transfer to in-situ electrochemical-spectral testing, ensuring that environmentally sensitive interfaces are not contaminated.

[0040] This integrated system is highly scalable. For example, it can be connected to surface processing or pretreatment equipment (such as focused ion beam equipment, plasma cleaners, etc.) via a vacuum interconnect channel, thereby completing the precision processing and subsequent characterization of electrode surfaces in the same controlled environment, and constructing a complete closed-loop research platform.

[0041] In other embodiments, the electrochemical sample stage, as a stand-alone module, can also be flexibly applied to other scenarios. For example, it can be connected to independently designed electrochemical workstations and spectrometers via an adapter; or, under non-vacuum interconnection conditions, it can be assembled in a glove box relying on its own sealing properties and then transferred to an independently operating spectrometer for testing.

[0042] Furthermore, the sealing housing 2 includes a main housing 21 fixed to the base 1 and an upper cover 22 with an injection channel 221. The upper cover 22 is detachably or fixedly connected to the main housing 21, and the inner side of the upper cover 22 is provided with a positioning structure for pressing and fixing the edge of the encapsulation layer 4.

[0043] The main housing 21 is fixed on the base 1, which serves as a fixed support and provides a mechanical mounting reference. The upper cover 22 is then placed on and fixed to the main housing 21. The positioning structure on the inner side of the upper cover 22 is used to press and fix the edge of the encapsulation layer 4, so that the edge area of ​​the encapsulation layer 4 forms a seal with the sealing housing 2. In this embodiment, the upper cover 22 and the main housing 21 are fixed to the base 1 by four screws.

[0044] The main shell 21 is a dense structure made of non-conductive material, preventing the liquid electrolyte from leaking out. The main shell 21 has a certain thickness. Optionally, the main shell 21 is made of an insulating material with good vacuum compatibility; the insulating material includes one or more insulating polymers or composites, selected from the group consisting of acrylates, fluoropolymers, ketones, nylon, acetals, olefins, carbonates, and styrene copolymers. Examples include polymethyl methacrylate, polytetrafluoroethylene, polyvinylidene fluoride, polyetheretherketone, polynylon, polyoxymethylene, polypropylene, polycarbonate, and acrylonitrile-butadiene-styrene copolymer.

[0045] Electrode assembly 3, i.e., the test battery, is assembled on the main casing 21. The test battery includes, but is not limited to, lithium-ion batteries, sodium-ion batteries, alkali metal / alkaline earth metal batteries, sulfur-based batteries, halogen batteries, and manganese-based batteries. The electrolyte inside the test battery can be a solid electrolyte, gel electrolyte, ionic liquid electrolyte, or liquid electrolyte, including but not limited to ether-based electrolytes, aqueous electrolytes, carbonate-based electrolytes, carboxylic acid ester-based electrolytes, ionic liquid-based electrolytes, polymer-based electrolytes, oxide-based electrolytes, and sulfide-based electrolytes.

[0046] In this embodiment, the working electrode 31 of the electrode assembly 3 is a three-dimensional or porous electrode loaded with electrochemically active material. The encapsulation layer 4 is tightly attached to the surface of the working electrode 31 for carrying the liquid electrolyte, thereby forming a closed micro-region for containing the liquid electrolyte between the encapsulation layer 4 and the surface of the working electrode 31. Under certain circumstances, the encapsulation layer 4 can be directly deposited on the surface of the working electrode 31, or it can be transferred and attached to the surface of the working electrode 31 after preparation. In other embodiments, a two-dimensional electrode can also be used as the working electrode 31.

[0047] Optionally, the surface of the working electrode 31 used to support the liquid electrolyte is a surface-planarized area with a surface roughness Ra of no more than 50 nm, preferably no more than 10 nm. The surface planarization treatment is performed by focused ion beam processing or mechanical polishing. By performing surface planarization on the working electrode 31, a finely processed flat area is formed, with a surface roughness reaching submicron or nanometer levels. This flat area is used to support the liquid electrolyte and is tightly bonded to the encapsulation layer 4 to form a uniform and stable liquid-solid-gas (vacuum) three-phase interface, minimizing photoelectron signal attenuation caused by interface irregularities.

[0048] A three-dimensional electrode loaded with active material is used as the working electrode 31. The three-dimensional electrode provides more permeation channels and contact interfaces for the liquid electrolyte, promoting the penetration and wetting of the liquid electrolyte. Its porous structure or particle filling significantly increases the effective reaction area, improves the electrochemical reaction rate, facilitates rapid ion diffusion, and optimizes the current distribution. In other embodiments, the working electrode 31 can also be a porous planar electrode.

[0049] Optionally, the material of the encapsulation layer 4 is selected from one or a combination of polymer films, graphene-based films, or functional films with nanoscale pores; the thickness of the encapsulation layer 4 is on the order of the photoelectron inelastic mean free path, preferably from 1 nm to 100 nm.

[0050] In this embodiment, the encapsulation layer 4 is a dense or functional thin film with nanoscale controllable pores. In the electrochemical in-situ characterization system, the encapsulation layer must meet the following core requirements: high X-ray transmittance, low photoelectron attenuation, excellent chemical stability, good mechanical sealing, and effective barrier capability against liquid electrolytes. Its thickness is typically between several nanometers and several hundred nanometers, preferably within the order of the inelastic mean free path of photoelectrons (1 nm to 100 nm), to maximize the escape probability of photoelectrons while ensuring mechanical sealing strength. Exemplary materials include, but are not limited to, polymer films (such as polyimide, silazane), low-dimensional layered materials (such as graphene and its derivatives, hexagonal boron nitride, etc.), metal-organic framework (MOF) films, or inorganic ceramic films.

[0051] The selected low-dimensional layered materials (such as graphene and hexagonal boron nitride) possess atomic-level flatness and ultra-thin thickness, achieving extremely high X-ray transmittance and photoelectron escape efficiency while maintaining high mechanical strength. Furthermore, their dense interlayer structure effectively blocks the penetration of liquid electrolyte molecules or ions. Metal-organic frameworks (MOFs) can be synthesized using controlled synthesis conditions or post-processing methods to form dense, non-porous thin film structures with sub-nanometer pore sizes, achieving physical barrier against liquid electrolytes while maintaining high X-ray transmittance. Their structures are highly designable; by selecting matching metal nodes and organic ligands, chemical inertness and stability can be ensured within the electrochemical testing potential window and in near-ambient pressure XPS detection environments, avoiding side reactions with the electrolyte or the introduction of additional catalytic activity.

[0052] Furthermore, the encapsulation layer material can be further optimized in terms of barrier properties, mechanical strength, and interface compatibility through composite, multilayer stacking, or surface functionalization, thereby maintaining the original state of the battery interface during long-term electrochemical cycling and spectral acquisition, and ensuring the authenticity and reliability of in-situ characterization data.

[0053] The thickness of the encapsulation layer 4 is designed to be no greater than 20 nm, preferably no greater than 5 mm. Its thickness must be sufficient to ensure that after the incident X-rays irradiate the interface between the active material and the liquid electrolyte of the working electrode 31 and excite the corresponding photoelectrons, the corresponding photoelectrons can escape from the encapsulation layer 4 and be finally received by the detector to obtain a highly sensitive spectroscopic signal.

[0054] The thickness of the encapsulation layer 4 can be optimized according to specific detection requirements and electrolyte properties. In some embodiments, the preprocessing function of the analytical device can be used to fine-tune the encapsulation layer 4. Since the encapsulation layer 4 is thin enough, the attenuation of the detection signal is greatly reduced, allowing X-rays to pass through. Based on this, a three-dimensional electrode is used as the working electrode 31, which enables simultaneous detection of liquids, solids, and solid-liquid interfaces. Selective detection can even be achieved by moving the position of the X-ray source. In some embodiments, if the electrolyte is a solid electrolyte or an ionic liquid electrolyte, the encapsulation layer 4 can be omitted.

[0055] Furthermore, the electrode assembly 3 also includes a reference electrode 33. The working electrode 31, the counter electrode 32, and the reference electrode 33 constitute a three-electrode system and are integrated within a sealed inner cavity. In this embodiment, the reference electrode 33 is located between the working electrode 31 and the counter electrode 32, and the reference electrode 33 and the working electrode 31 form a potential control loop through a liquid electrolyte.

[0056] By adding a reference electrode 33, the electrochemical sample stage integrates a working electrode 31, a counter electrode 32, and a reference electrode 33, forming a three-electrode system. The reference electrode 33 and the working electrode 31 form a potential control loop through a liquid electrolyte, which can provide a stable potential reference and ensure accurate measurement of the potential of the working electrode 31.

[0057] In this embodiment, the electrode assembly 3 further includes a support platform 35, which is disposed on the base 1. The counter electrode 32 is disposed on the support platform 35, and the reference electrode 33, the working electrode 31, and the encapsulation layer 4 are sequentially arranged above the counter electrode 32 and limited by the upper cover 22. The support platform 35 is made of an insulating material (e.g., ceramic, polytetrafluoroethylene). The counter electrode 32 includes, but is not limited to, three-dimensional structures, planar structures, plate electrodes, and porous electrodes, which can be wetted by liquid electrolyte and achieve ion conduction while also satisfying electron conduction within the electrode. In other embodiments, the support platform 35 and the main housing 21 can also be designed as an integral structure.

[0058] Furthermore, the surface of the working electrode 31 for carrying the liquid electrolyte is oriented generally parallel to the mounting plane of the base 1, such that when the base 1 is mounted horizontally, the surface is approximately horizontal.

[0059] "Approximately horizontal state" means that, with the plane of base 1 as a reference, the angular deviation between the plane of working electrode 31 and the plane of base 1 is less than 2 degrees, and base 1 is used to place horizontally on the spectrometer. In this embodiment, the planes of working electrode 31, counter electrode 32, reference electrode 33, and base 1 are all parallel. By designing base 1 to be placed horizontally on the energy dispersive spectrometer, and designing the angular deviations of working electrode 31, counter electrode 32, and reference electrode 33 from the plane of base 1 to be small or even parallel, the interference of gravity on the liquid electrolyte interface is significantly reduced or eliminated, thus avoiding the flow of liquid electrolyte.

[0060] The specific installation location of the electrochemical sample stage needs to be determined based on the space of the energy dispersive spectrometer sample chamber. If the sample chamber has sufficient space, the electrochemical sample stage can be installed inside the sample chamber. If the sample chamber space is limited or independent operation is required, the electrochemical sample stage can be installed on the tabletop of the energy dispersive spectrometer.

[0061] In some embodiments, the base 1 can also be connected to a drive device, which is connected to an energy spectrometer, enabling lifting, translation, and flipping.

[0062] Optionally, the electrode assembly 3 further includes a separation element. The separation element and the reference electrode 33 are both located between the working electrode 31 and the counter electrode 32. The separation element is used to isolate the working electrode 31 from the counter electrode 32. By using a separation element to isolate the working electrode 31 from the counter electrode 32, direct contact and mixing of the reactants at the two electrodes can be avoided, which could cause side reactions. It also enables the ion pathways of the working electrode 31 and the counter electrode 32 to be maintained.

[0063] In this embodiment, the separating element is a diaphragm 34; the diaphragm 34 includes, but is not limited to, polyolefin diaphragms (such as PP, PE, etc.), cellulose diaphragms, glass fiber diaphragms, proton exchange membranes, solid electrolyte membranes, and gel electrolyte membranes; the size of the diaphragm 34 is larger than the size of the working electrode 31 and the counter electrode 32. In other embodiments, insulation between the working electrode 31 and the counter electrode 32 can be ensured by controlling the distance between the working electrode 31 and the counter electrode 32, or by using insulating materials.

[0064] The reference electrode 33 can be disposed above or below the diaphragm 34, but the reference electrode 33 cannot directly contact the working electrode 31 and the counter electrode 32. The diaphragm 34 can also be configured as a double layer, with the reference electrode 33 disposed between the two layers of the diaphragm 34, thereby isolating the reference electrode 33. The reference electrode 33 includes, but is not limited to, Ag / AgCl electrodes, saturated calomel electrodes, copper / copper sulfate electrodes, mercury / mercuric oxide electrodes, platinum electrodes, etc., and its purpose is to provide a stable potential reference, thereby determining the potentials of the working electrode 31 and the counter electrode 32.

[0065] Furthermore, the electrochemical sample stage also includes a vacuum-compatible electrical connection component disposed on the base 1. The electrical connection component is electrically connected to the working electrode 31 and the counter electrode 32 via a lead that passes through the sealed housing 2, for connecting the electrode assembly 3 to an external electrochemical workstation.

[0066] Furthermore, the electrical connection components include a working electrode adapter 6 and a counter electrode adapter 7, which are fixed to the base 1 and insulated from each other. Specifically, the electrode assembly 3 includes a working electrode wiring 36, and the electrochemical sample stage also includes an insulating element and a working electrode adapter 6. The working electrode adapter 6 is fixed to the base 1, and an insulating element is provided between the working electrode adapter 6 and the base 1. One end of the working electrode wiring 36 is sealed through the sealing housing 2 and connected to the working electrode 31, and the other end of the working electrode wiring 36 is connected to the working electrode adapter 6.

[0067] The working electrode adapter 6 is fixed on the base 1, and the working electrode 31 is connected to the working electrode adapter 6 by the working electrode wiring 36. This can adapt to electrodes of different types and sizes, ensuring the flexibility of electrochemical testing. An insulating element is set between the working electrode adapter 6 and the base 1. The insulating element can effectively prevent the working electrode adapter 6 and the base 1 from direct contact, preventing accidental discharge or grounding.

[0068] Electrode assembly 3 also includes counter electrode wiring 37, and electrochemical sample stage also includes counter electrode adapter 7. Counter electrode adapter 7 is stacked and fixed on working electrode adapter 6. An insulating element is provided between counter electrode adapter 7 and working electrode adapter 6. One end of counter electrode wiring 37 is sealed through the sealed housing 2 and connected to counter electrode 32, and the other end of counter electrode wiring 37 is connected to counter electrode adapter 7.

[0069] The working electrode adapter 6 and the counter electrode adapter 7 can be in the form of spring pins, pads or sockets, etc., for coupling with the corresponding electrical contact points or vacuum feedthrough devices on the external spectrometer sample stage, so as to lead the electrical signal to the external electrochemical workstation.

[0070] Stacking the counter electrode adapter 7 on the working electrode adapter 6 reduces the space occupied by the base 1 and ensures a compact structure; the counter electrode 32 is connected to the counter electrode adapter 7 using the counter electrode wiring 37; an insulating element is provided between the counter electrode adapter 7 and the working electrode adapter 6, which can effectively prevent direct contact between the counter electrode adapter 7 and the working electrode adapter 6 and prevent short circuits.

[0071] In this embodiment, the insulating element is a gasket 5; the electrode assembly 3 also includes a reference electrode wire 38, one end of which is sealed through the sealing housing 2 and connected to the reference electrode 33, and the other end is connected to the column of the base 1, thereby ensuring that the reference electrode 33 and the working electrode 31 form a stable potential difference circuit, thereby obtaining the real-time potential change of the working electrode 31.

[0072] In this embodiment, three wiring holes are provided on the main housing 21 for wiring, corresponding to the working electrode wiring 36, the counter electrode wiring 37, and the reference electrode wiring 38, respectively. The working electrode wiring 36, the counter electrode wiring 37, and the reference electrode wiring 38 are all tightly embedded in their respective wiring holes to ensure no gas or liquid leakage under vacuum conditions. When the wiring is inserted into the corresponding wiring hole and all electrode lines are connected, liquid electrolyte will not leak from the main housing 21. The working electrode wiring 36 is connected to the side of the working electrode 31 away from the encapsulation layer 4, the reference electrode wiring 38 is connected to the edge of the reference electrode 33, and the counter electrode wiring 37 is connected to the side of the counter electrode 32 away from the working electrode 31. In other embodiments, if the electrodes and adapter are not connected by wiring, wireless transmission or flexible contact can also be used.

[0073] Specifically, the working electrode adapter 6, the counter electrode adapter 7, and the washer 5 are fixed to the base 1 by fasteners 8; there are three washers 5; the fasteners 8 are screws 8a and nuts 8b, the screw 8a passes through the base 1, and the first washer 5, the working electrode adapter 6, the second washer 5, the counter electrode adapter 7, and the third washer 5 are stacked and fitted over the screw 8a in sequence, and locked by the nut 8b. Both the screw 8a and the nut 8b are made of insulating material, such as polytetrafluoroethylene, to prevent short circuits / grounding caused by electronic contact between different circuits.

[0074] During testing, the base 1 of the electrochemical sample stage is installed on the sample chamber or table of the energy dispersive spectrometer (EDS). The various components of the electrode assembly 3 are then mounted on the base 1. Corresponding adapters are integrated on the base 1, and the working electrode 31, counter electrode 32, and reference electrode 33 are connected to these adapters via appropriate wiring. These are then connected to the external circuit via thermocouples for real-time electrochemical testing. X-rays enter from above the top cover 22, pass through the encapsulation layer 4, and reach the interface between the working electrode 31 and the electrolyte. After exciting a photoelectron signal, the photoelectrons escape through the encapsulation layer 4. The photoelectron signal received by the detector is then linked to the electrochemical information of the electrochemical workstation to obtain the chemical information at the electrochemical reaction interface under the corresponding battery conditions. The EDS can provide different gas atmospheres (the atmosphere can be set according to the different electrolytes used). By controlling the vapor pressure, the pressure difference between the inside and outside of the battery is reduced, making the battery containing liquid electrolyte more stable and structurally more reliable under vacuum.

[0075] The electrochemical sample stage provided in this embodiment employs an encapsulation layer 4 that allows photoelectrons to pass through while preventing the liquid electrolyte from evaporating and also allows for the escape of internal gas from the battery. Furthermore, the horizontal placement of the sample stage eliminates the interference of gravity on the liquid electrolyte. It integrates a three-electrode system comprising a working electrode 31, a counter electrode 32, and a reference electrode 33, enabling real-time correlation between electrochemical and chemical signals. It is suitable for solid, liquid, and gel electrolytes and is applicable to a wide vacuum range (10⁻⁶). -8 (mbar to atmospheric pressure).

[0076] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. An electrochemical sample stage for near-ambient pressure photoelectron spectroscopy analysis, characterized in that, include: Base (1) is used to provide a mechanical mounting reference; A sealed housing (2) is fixed on the base (1) and together with the base (1) defines a sealed inner cavity. An injection channel (221) is provided on the sealed housing (2). The electrode assembly (3) is sealed within the sealed inner cavity and includes at least one working electrode (31) and one counter electrode (32). The working electrode (31) has a surface for carrying liquid electrolyte. The encapsulation layer (4) has an edge region that forms a seal with the sealing housing (2) and covers the surface of the working electrode (31), thereby forming a closed micro-region for containing the liquid electrolyte between the encapsulation layer (4) and the surface of the working electrode (31). The encapsulation layer (4) in the corresponding area of ​​the incident channel (221) is selected in terms of material and thickness to allow the excitation rays to penetrate and act on the electrode assembly (3), and to allow the photoelectrons generated therefrom to escape to the outside of the sealed inner cavity, while blocking the macroscopic volatilization of the liquid electrolyte.

2. The electrochemical sample stage according to claim 1, characterized in that, The surface of the working electrode (31) for carrying the liquid electrolyte is oriented generally parallel to the mounting plane of the base (1), such that when the base (1) is mounted horizontally, the surface is approximately horizontal.

3. The electrochemical sample stage according to claim 2, characterized in that, The electrode assembly (3) also includes a reference electrode (33). The working electrode (31), the counter electrode (32) and the reference electrode (33) constitute a three-electrode system and are integrated in the sealed inner cavity.

4. The electrochemical sample stage according to any one of claims 1-3, characterized in that, The surface of the working electrode (31) used to carry the liquid electrolyte is a region that has undergone surface smoothing treatment, and its surface roughness Ra is not greater than 50 nm, preferably not greater than 10 nm.

5. The electrochemical sample stage according to any one of claims 1-3, characterized in that, It also includes a vacuum-compatible electrical connection component disposed on the base (1), which is electrically connected to the working electrode (31) and the counter electrode (32) via a lead that is sealed through the sealed housing (2) for connecting the electrode assembly (3) to an external electrochemical workstation.

6. The electrochemical sample stage according to claim 5, characterized in that, The electrical connection components include a working electrode adapter (6) and a counter electrode adapter (7) that are fixed to the base (1) and insulated from each other.

7. The electrochemical sample stage according to any one of claims 1-3, characterized in that, The thickness of the encapsulation layer (4) is on the order of the inelastic mean free path of optoelectronics, preferably from 1 nm to 100 nm.

8. The electrochemical sample stage according to any one of claims 1-3, characterized in that, The material of the encapsulation layer (4) is selected from one or a combination of polymer films, low-dimensional layered materials, metal oxide films, or functional films with nanoscale pores.

9. The electrochemical sample stage according to any one of claims 1-3, characterized in that, The sealing housing (2) includes a main housing (21) fixed to the base (1) and an upper cover (22) with the incident channel (221). The upper cover (22) is detachably or fixedly connected to the main housing (21). The inner side of the upper cover (22) is provided with a positioning structure for pressing and fixing the edge of the encapsulation layer (4).

10. The electrochemical sample stage according to claim 9, characterized in that, The main housing (21) is made of an insulating material with good vacuum compatibility.

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