Storage devices and manufacturing methods
By forming an ion insulating barrier layer within electrode cavities, the method addresses the challenge of increasing microbattery capacity and preventing short circuits, ensuring efficient ionic isolation and maintaining electrode thickness.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2025-09-01
- Publication Date
- 2026-03-13
AI Technical Summary
Existing methods for manufacturing microbatteries face challenges in increasing electrode thickness to enhance capacity while minimizing size, leading to surface defects and potential short circuits due to limited deposition methods and polishing solutions that reduce electrode thickness.
A method involving the formation of an ion insulating barrier layer within cavities in the electrode, which separates the electrode and electrolyte, preventing short circuits and maintaining electrode thickness by ensuring local ionic isolation without significant reduction.
The method effectively limits short circuits and maintains high electrode thickness, enhancing storage capacity and performance by allowing ionic current circulation across the entire electrode surface with minimal surface loss.
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Abstract
Description
Technical Field
[0001] The present invention relates to the field of electrochemical energy storage, in particular in the form of microbatteries, and is related to microelectronic devices with electrodes (and thus to the manufacture of electrochemical microstorage components). The present invention applies to the manufacture of microelectronic devices that provide storage and the like. A microelectronic device means any type of device manufactured by microelectronic means. These devices include, in particular, microelectromechanical or electromechanical devices (MEMS, NEMS, etc.) and optical or optoelectronic devices (MOEMS, etc.) in addition to devices having purely electronic purposes. This includes the application of electrochemical microstorage component types (any type of microbattery, microsupercapacitor, solid ion component).
[0002] A specific interest of the present invention is thus the manufacture of electrochemical energy storage devices. This includes, in particular, battery-type devices, in particular those on the microelectronic scale called microbatteries, preferably solid-state, rechargeable batteries or capacitors using an electrolyte.
Background Art
[0003] Prior Art Electrochemical energy storage systems are generally manufactured by the sequential deposition onto a substrate of a first current collector, a first electrode, or an electrolyte or ion conductor, a second electrode, and a second current collector. Encapsulation by deposition of additional layers or by transfer of a cover is often necessary to protect the system from chemical reactivity with oxygen and water vapor.
[0004] Miniaturization of devices involves, in particular, enabling the manufacture of small energy sources capable of storing a sufficient amount of energy for applications, even if they are only a few square centimeters in size. The capacity of a microbattery is directly proportional to the volume of the two electrodes, especially the positive electrode. The active surface of the latter is severely limited by the final size of the microbattery so that it can be integrated into the final device without becoming too large. Therefore, an available method for increasing the battery capacity while minimizing its size is to increase the thickness of the electrodes, especially the anode. Typically, a thickness of more than 10 μm is required.
[0005] However, increasing this thickness can lead to surface defects related to the deposition method, potentially resulting in short circuits in energy storage devices. In particular, electrode materials such as LiCoO2 are deposited by cathode sputtering methods, which are generally limited to low thicknesses of less than 10 micrometers.
[0006] The document US2021 / 0359339A1 proposes an attempt to solve the aforementioned problem by suggesting polishing the top surface of the electrode. However, this solution was unsatisfactory because, when surface defects extend very deep into the electrode, polishing must be effective over this same depth. This leads to a very large reduction in electrode thickness, which is counterproductive to the goal of increasing battery capacity. [Overview of the Initiative] [Problems that the invention aims to solve]
[0007] The objective, therefore, is to propose an electrode manufacturing method that allows for a considerable thickness, which is even more advantageous, particularly from an electrical standpoint, without significantly damaging the performance of the electrodes, or even without damaging them at all.
[0008] Other purposes, features, and advantages will become apparent upon reviewing the following description and attached drawings. [Means for solving the problem]
[0009] To achieve this objective, a first aspect of the present invention relates to a method for manufacturing electrodes for a solid-state battery, comprising at least the following steps: a. Manufacturing of an electrode on a support, wherein the electrode has an upper surface opposite the support, and the electrode has at least one cavity extending from its upper surface, and b. Formation of an ion insulating layer called a barrier layer on the upper surface of the electrode and in at least one cavity, c. Removal of the battery layer to expose the top surface of the electrodes, while leaving a portion of the barrier layer extending into at least one cavity in place.
[0010] The portion of the barrier layer remaining in place within at least one cavity therefore separates the electrode and electrolyte within that cavity. This thus ensures local ionic isolation between these two layers. This makes it possible to limit, and even prevent, short circuits within the storage system containing electrodes formed by the method described above. In particular, it has been observed that this local ionic isolation makes it possible to avoid the appearance of highly concentrated electric field regions during the operation of the storage system, regions that would severely impair the system's performance. The barrier layer also simultaneously prevents the materials forming the electrolyte and electrodes from cracking under the influence of these high currents.
[0011] Local ionic insulation between the electrode and electrolyte is only effective within the cavity, allowing the ionic current to circulate between these two layers across the entire remaining surface of the electrode. Therefore, the exchange surface between the electrode and electrolyte lost due to ionic insulation is estimated to be less than 5% of the total surface. This ratio is perfectly acceptable, especially considering the benefits that insulation provides.
[0012] Furthermore, the proposed solution does not require a reduction in electrode thickness, as is the case with current solutions (particularly US 2021 / 0359339 A1). While a low thickness of the electrode may be removed during the partial removal of the barrier layer, this thickness is very low compared to the total thickness of the electrode. In particular, the method according to the present invention does not require the removal of the electrode over the thickness over which the cavity extends. Thus, the electrode thickness is very high and even fully maintained, which is beneficial to the capacity of the storage system.
[0013] A second aspect of the present invention relates to a method for manufacturing an electrochemical energy storage device, comprising manufacturing at least one electrode by carrying out a method according to the first aspect of the present invention.
[0014] A third aspect of the present invention relates to an electrochemical energy storage device comprising a current collector, electrodes, and an electrolyte in a laminate on a support, wherein the electrodes include at least one cavity formed in a hollow portion from the upper surface of the electrode, and an ion insulating layer called a barrier layer at least partially fills the at least one cavity, the barrier layer thus locally separating the electrode and the electrolyte.
[0015] The advantages and technical effects described in relation to the method according to the first aspect of the present invention are applicable to the methods and devices according to the second and third aspects of the present invention with necessary modifications.
[0016] The object, objectives, features, and advantages of the present invention will best become apparent from a detailed description of the latter embodiments shown in the accompanying drawings below: [Brief explanation of the drawing]
[0017] [Figure 1A] Figure 1A illustrates the growth of defects during electrode formation. [Figure 1B] Figure 1B illustrates the growth of defects during electrode formation. [Figure 1C]Figure 1C is an image obtained by a scanning electron microscope (SEM) of the defects that typically appear during the growth of the electrodes. [Figure 2A] Figure 2A illustrates the formation of cavities within the electrode as the defects relax. [Figure 2B] Figure 2B illustrates the concentration of the electric field in the cavity during the operation of the energy storage system including the electrode of Figure 2A. [Figure 3A] Figure 3A illustrates the different steps of an example of the method according to the present invention. [Figure 3B] Figure 3B illustrates the different steps of an example of the method according to the present invention. [Figure 3C] Figure 3C illustrates the different steps of an example of the method according to the present invention. [Figure 3D] Figure 3D illustrates the different steps of an example of the method according to the present invention. [Figure 3E] Figure 3E illustrates the different steps of an example of the method according to the present invention. [Figure 3F] Figure 3F illustrates the different steps of an example of the method according to the present invention. [Figure 4A] Figure 4A is an enlarged view of the upper surface of the electrodes of Figures 3C and 3D. [Figure 4B] Figure 4B is an enlarged view of the upper surface of the electrode of Figure 3F. [Figure 5A] Figure 5A illustrates an alternative embodiment in which the particles present within the cavity on the surface of the electrode are removed. [Figure 5B] Figure 5B illustrates an alternative embodiment in which the particles present within the cavity on the surface of the electrode are removed. [Figure 5C] Figure 5C illustrates an alternative embodiment in which the particles present within the cavity on the surface of the electrode are removed.
Mode for Carrying Out the Invention
[0018] The drawings are given as examples and do not limit the invention. They constitute a schematic diagram of principle intended to facilitate understanding of the invention and do not need to be to scale of actual applications. In particular, the dimensions do not reflect reality.
[0019] Detailed explanation Before beginning a detailed review of embodiments of the present invention, the following are some optional features that can be used selectively in combination or as substitutes.
[0020] According to one embodiment, the electrodes are manufactured by physical vapor deposition or electrochemical deposition.
[0021] According to one embodiment, LiCoO2 is used to manufacture electrodes.
[0022] According to one preferred embodiment, the method further includes an annealing step of electrodes prior to the step of forming a barrier layer. This annealing step allows for the removal of at least some of the particles located within the cavity. Such annealing allows for the removal of the most troublesome and largest particles with good efficiency. Advantageously, the annealing is performed at a temperature of 300°C or higher, for example, substantially equal to 400°C. Alternatively, or in combination with the annealing step, particle removal can be performed with the use of ultrasound and / or mechanical action. This mechanical action can be performed, for example, by a scrubber using a jet or brush.
[0023] According to one preferred embodiment, the method further includes the step of polishing the electrode from its upper surface prior to the step of forming the barrier layer. Polishing allows for loosening of particles located within the cavity.
[0024] According to one embodiment, the polishing step is configured to taper the electrode over a thickness of 100 nm or more, preferably 500 nm or more, and / or 2 μm or less. For example, over a thickness substantially equal to 1 μm.
[0025] According to one preferred embodiment, the step of removing the barrier layer includes at least one of a chemical-mechanical polishing step and a grinding step.
[0026] According to one preferred embodiment, the step of removing the barrier layer includes the following steps: a. Deposition of a resin layer on a barrier layer, wherein the portion of the resin layer located above at least one cavity has a greater thickness than the portion of the resin layer not located above at least one cavity, and b. Etching of the resin layer and the barrier layer to expose the upper surface of the electrode while leaving a portion of the barrier layer extending into at least one cavity in place.
[0027] According to one embodiment, the resin layer is deposited such that it has a thickness of 2 μm or less in the portion that is not located on at least one cavity.
[0028] According to one embodiment, the barrier layer has a thickness of 10 nm or more, preferably 30 nm or more.
[0029] According to one embodiment of the method for manufacturing a chemical energy storage device according to the present invention, the latter further includes forming a current collector on a support, and then manufacturing electrodes on the current collector.
[0030] Certain parts of the device of the present invention may have electrical functions. Some are used for ionic conductivity, and electrodes, current collectors, or homogeneous materials mean elements formed from at least one material having sufficient ionic conductivity to perform the desired function in the application. Conversely, ionic or dielectric insulators mean materials that guarantee ionic insulating properties in the application.
[0031] Electrochemical energy storage devices refer to devices that operate with an electrolyte layer, preferably in solid form, in combination with low-ion-conductivity and high-ion-conductivity working parts around the electrolyte layer, enabling energy storage in the form of an increase in potential difference or energy release in the form of a decrease in potential difference. In the field of microelectronics, these can be microbatteries, meaning such devices having dimensions on a microelectronic scale, in particular having an overall thickness of tens of microns, for example, less than 100 micrometers.
[0032] Generally, electrochemical energy storage devices include two electrodes separated by an electrolyte. During discharge, the anode (negative electrode) is the site of oxidation, and ions pass through the electrolyte to the cathode (positive electrode), where they undergo reduction and are inserted into a specific material (host material); the electrons thus produced supply energy to the external circuit. During charging, ions move in the reverse direction, and electrons are supplied by the external circuit.
[0033] "Selective reverse etching" or "etching with reverse selectivity" refers to etching configured to remove layer A or layer B on the opposite side of material A or material B, with an etching rate of material A that is faster than the etching rate of material B. Selectivity is the ratio between the etching rate of material A and the etching rate of material B. The selectivity between A and B is expressed as SA:B.
[0034] Within the scope of the present invention, the terms “above,” “located above,” “covering,” “below,” “opposite side,” and their equivalents are not necessarily “in contact.” Therefore, for example, deposition, transport, joining, assembly, or application of the first layer onto the second layer does not necessarily mean that the two layers are in direct contact with each other, but rather that the first layer covers the second layer at least partially, either by direct contact with it or by being separated from it by at least one other layer or at least one other element.
[0035] A layer can further consist of multiple sublayers of the same material or different materials.
[0036] A substrate, layer, or device having a "based on" material M means a substrate, layer, or device containing only material M, or material M and selectively other materials, such as alloying elements, impurities, or doping elements.
[0037] A system of orthonormalities, preferably including the X, Y, and Z axes, is represented in Figure 3A. This system can be extended to apply to other figures.
[0038] In this patent application, thickness will preferably be referred to for layers, and height will preferably be referred to for structures or devices. Height is taken perpendicular to the cross-section XY. Thickness is taken along a direction perpendicular to the main extending surface of the layer. Therefore, if it extends mainly along the cross-section XY, the layer will usually have thickness along Z, and protruding elements, such as grooves, will have height along Z. The relative terms “above,” “below,” and “below” preferably refer to positions taken along the Z direction.
[0039] The terms "effectively," "approximately," and "about" mean "plus or minus 10%, preferably 5%."
[0040] Figures 1A to 2B illustrate the shortcomings of the prior art. More specifically, Figure 1A represents the initiation of electrode 30' formation on a laminate formed by the support 10' and the current collector 20'. As illustrated, quite conventionally, at least one defect 34' appears during the deposition of electrode 30'. During the deposition of electrode 30', this defect 34' grows and ends by extending to the upper surface 31' of electrode 30'. An SEM view of such a defect 34' is shown in Figure 1C, excerpted from the literature Influence of Growth Defects on the Corrosion Resistance of Sputter-Deposited TiAlN Hard Coatings, Panjan et al, Coatings 2019. As described above, such defects 34' can lead to short circuits in energy storage devices. In particular, it is noteworthy that these defects can appear quite early in the growth of the electrode and therefore extend over a very large portion of the electrode height, making them highly detrimental and promoting short circuits.
[0041] Furthermore, as illustrated in Figure 2A, the defects 34' can be removed by spontaneous external intervention or, for example, cut off from themselves under the influence of one or more method steps. This typically creates a cavity 33' with a very high height / width display aspect ratio. After the formation of the electrolyte 50' and the second electrode 60' on the upper surface of electrode 30' and in cavity 33', it is observed that the electric field is highly concentrated at the bottom of cavity 33'. This is very detrimental to the operation of the storage system and can, in particular, cause a short circuit. Specifically, this phenomenon can cause the formation of lithium dendrites in the electrolyte, for example, leading to a short circuit.
[0042] These drawbacks are what this invention aims to limit and even eliminate.
[0043] Different embodiments of the method according to the present invention will now be described with reference to Figures 3A to 5C.
[0044] A support 10 is provided first. This support 10 has an upper surface 11 that mainly extends in a plane parallel to the cross-section XY. The cross-section XY is defined by a first direction X and a second direction Y. The support 10 is formed from a plate of a semiconducting material, such as silicon or any other organic or inorganic material, such as glass. If the support 10 is electrically conductive, it may include an electrically insulating layer on at least one surface.
[0045] Conventionally, the current collector 20 is subsequently formed on the upper surface 11 of the support 10. In the sense of this application, the term "current collector" means a part of a device that has the function of connecting electrodes to external elements of the device, i.e., a part located outside the stack of layers of the device and generally encapsulated. A metal with excellent electrical conductivity can be used for this part. This is the case with platinum, but less expensive materials such as titanium are also possible.
[0046] The electrode 30 is formed on the upper surface 21 of the current collector, opposite the support 10 (see Figure 3A). The electrode is fabricated, for example, from LiCoO2 (lithium cobalt dioxide). The electrode 30 is typically formed by physical vapor deposition (PVD) or electrochemical deposition (ECD). The transition from Figure 3A to Figure 3B illustrates the asymptotic formation of the electrode by one of these methods. All possible different deposition methods lead to noticeable surface roughness of the electrode 30.
[0047] The electrode 30 has an upper surface 31 opposite to the support 10 and the current collector 20. This typically extends in a plane parallel to the cross-section XY.
[0048] It should be understood that Figure 3B is a particularly schematic representation and does not specifically show defects located on the upper surface of electrode 30.
[0049] The electrode 30 has a thickness e30 that is measured perpendicular to its upper surface 31, and therefore normally along the direction Z. The electrode thickness e30 is typically greater than 10 μm, preferably greater than 20 μm. It can be between 20 and 200 μm, in particular.
[0050] As shown in Figure 3C, an ion insulating material-based layer is formed on the upper surface 31 of the electrode 30. This layer may be specifically called a barrier layer 40. It can be based on at least one of the following materials, for example: Al2O3, TiO2, TiN, Ti, Al, Pt, SiN, SiON, TaN, Ta.
[0051] Typically, the barrier layer 40 is uniformly deposited on the laminate. Therefore, due to the removal of the electrodes 30 from the current collector 20 and the removal of the current collector 20 from the support 10, the barrier layer 40 is initially deposited on the upper surface 21 of the current collector 20 and the upper surface 11 of the support 10. Thus, as shown in Figure 3D, it is possible to remove a portion of the barrier layer 40, for example, the portion extending over the upper surface 11 of the support 10. Advantageously, this removal allows for the replacement of at least a portion of the upper surface 21 of the current collector 20.
[0052] The barrier layer 40 has a thickness e40 measured perpendicular to the upper surface 31 of the electrode 30, and therefore typically along the Z direction. The thickness e40 of the barrier layer 40 is typically greater than 10 nm, for example, substantially equal to 50 nm.
[0053] Figure 4A is a magnified view of Figures 3C and 3D at the upper surface 31 of the electrode 30. It illustrates that defects are present on the surface of the electrode 30. As shown, cavities 33 extend from the upper surface 31 of the electrode 30. These cavities 33 define the hollow portions within the electrode 30. In certain cavities 33, additional defects may be found in the form of particles 34.
[0054] As shown in the figure, the deposition of the barrier layer 40 is configured to extend into the cavity 33. When they are present in the cavity 33, the barrier layer 40 further covers the particles 34. Atomic layer deposition (ALD) is preferred for the barrier layer deposition, as it allows deposition even to the bottom of the cavity 33, even when these particles have a high height / width display aspect ratio.
[0055] The barrier layer 40 is then partially removed to partially, and preferably entirely, renew the area of the upper surface 31 of the electrode 30 that does not have a cavity 33. During this removal, a portion of the barrier layer 40 is held in place and extends into the cavity 33. In this way, the remaining portion of the barrier 40 * The portion of the barrier layer 40 that is maintained in place during this partial removal step, called the partial removal step, can be continuous (if there is a single cavity on the surface of the electrode 30) or discontinuous (if there are several cavities). In the latter case, the remaining portion of the barrier layer 40 * Each is formed by multiple parts extending into the cavity 33. Advantageously, the remaining barrier portion 40 * It completely covers each cavity 33.
[0056] Partial removal of the barrier layer 40 can be carried out by different methods.
[0057] According to the examples, this removal is carried out by polishing, for example by chemical-mechanical polishing (CMP), or by grinding. Polishing can be effective to a thickness greater than the thickness of the barrier layer 40 and can be continued within the electrode. Polishing can be carried out on a thickness of, for example, 100 nm. However, it should be noted that it is sufficient if the polishing allows the upper surface 31 of the electrode 30 to be renewed.
[0058] According to another embodiment, the barrier layer 40 is removed by the uneven deposition of a resin layer on the barrier layer 40, followed by etching of the barrier layer 40 through this resin layer. In this way, the resin layer is deposited such that it has a first thickness in the portion not above the cavity 33 and a second thickness distinct from the first thickness in the portion above the cavity 33. The deposition of the resin layer is configured such that the second thickness is greater than the first thickness, for example, at least twice the first thickness. For example, the first thickness may be 2 μm or less and the second thickness may be 4 μm or more. The etching step is then performed and configured to stop when the first thickness is completely removed and the upper surface 31 of the electrode 30 is renewed. With the second thickness greater than the first thickness, the region of the barrier layer 40 located within the cavity 33 is not etched. Stopping this etching may simply be done by time, or the etching may be selective etching opposite to the electrode material.
[0059] Combining these different removal techniques can be considered.
[0060] In this way, the laminate shown in Figure 3E is obtained.
[0061] As shown in Figure 3F, conventionally, the electrolyte 50 and the second electrode 60 are subsequently formed on the electrode 30. The electrolyte 50 can be made of, for example, amorphous lithium nitride phosphate (LiPON). The second electrode 60 can be made of, for example, titanium. In this case, the second electrode forms the anode, and the cathode is formed by the electrode 30.
[0062] Remaining barrier portion 40 * This separates the electrode 30 and electrolyte 50 in each cavity 33. This thus ensures local ionic isolation between these two layers. This makes it possible to limit and even prevent short circuits in the storage system.
[0063] Figures 5A to 5C illustrate advantageous embodiments of the method according to the present invention. In this embodiment, the removal of particles 34 located within the cavity 33 is carried out before the formation of the barrier layer 40.
[0064] It should be noted that during the partial removal of the barrier layer 40, the particles 34 present in the cavity 33 occasionally loosen. With the barrier layer 40 deposited on top of these particles 34, the loosening of these particles creates a local absence of the barrier layer at the bottom of the cavity 33. Therefore, insulation is no longer locally guaranteed in the cavity 33 where the particles 34 are present and subsequently loosened. To prevent this, a step of removing at least some of the particles 34 is advantageously provided before the step of depositing the barrier layer 40.
[0065] To achieve this, for example, electrode annealing can be performed (Figure 5B). This annealing generates stress in the particles 34, causing the particles 34 to delaminate, thereby producing a finish on the electrode 30. This method would work particularly well for electrodes formed from materials with a high coefficient of thermal expansion in their current state, especially in the case of LiCoO2.
[0066] It is also possible to perform a polishing step that also has the effect of removing the particles 34. This polishing can be performed over a thickness of, for example, 1 μm or less.
[0067] Annealing and polishing can be naturally combined to remove as many particles 34 as possible.
[0068] It should be noted that the annealing step may be sufficient to remove the particles 34 that are most disruptive to the operation of the storage system, i.e., those with the largest dimensions. Generally, particles 34 with a height of 50% or less of the height of the electrode 30 are assumed to be undisturbing.
[0069] Another object of the present invention relating to an electrochemical energy storage device. This device is illustrated in Figure 3F. It includes a support 10, a current collector 20, an electrode 30, and an electrolyte 50 within a laminate. As described above, the electrode 30 has at least one cavity 33 extending from its upper surface 31. Furthermore, the device according to the present invention includes the remaining barrier portion of the barrier layer as described above, thus separating the electrode 30 and the electrolyte 50 in the cavity 33. This storage device can be obtained by carrying out any one of the embodiments of the method described above. In particular, the particles 34 present in the cavity 33 can or cannot be removed during the manufacture of the device. The final device can therefore or cannot have residues of particles 34, or even whole particles, in the cavity 33 (enlarged in Figure 4B or 5C).
[0070] Considering the different embodiments described above, the present invention appears to offer an effective solution, in particular, for improving the performance of electrodes in electrochemical energy storage devices. Specifically, the present invention limits the problems of short circuits and cracking in electrolytes and in storage systems in general, and allows electrodes to have high thicknesses (even tens or hundreds of micrometers). This is achieved by increasing the storage capacity of the system and thus resulting in a more efficient system.
[0071] The present invention is not limited to the embodiments described above, but extends to all embodiments covered by the present invention.
Claims
1. A method for manufacturing electrodes for a solid-state battery, comprising at least the following steps: Manufacturing of an electrode (30) on a support (10), wherein the electrode (30) has an upper surface (31) opposite to the support (10), and the electrode has at least one cavity (33) extending from its upper surface (31) into a hollow portion, Formation of an ion insulating layer called a barrier layer (40) on the upper surface (31) of the electrode (30) and within the at least one cavity (33), The steps include removing the battery layer (40) so that the upper surface (31) of the electrode (30) is exposed, while leaving a portion of the barrier layer (40) extending into the at least one cavity (33) in a predetermined position, Methods that include...
2. The method according to claim 1, wherein the electrode (30) is manufactured by physical deposition or electrochemical deposition.
3. To manufacture the electrode (30) LiCoO ２ The method according to claim 1 or 2, wherein the method is used.
4. The method according to any one of claims 1 to 3, further comprising the step of annealing the electrode (30) before the step of forming the barrier layer (40).
5. The method according to any one of claims 1 to 4, further comprising the step of polishing the electrode (30) from its upper surface (31) before the step of forming the barrier layer (40).
6. The method according to claim 5, wherein the polishing step is configured to tapere the electrode (30) over a thickness of 100 nm or more and / or 2 μm or less.
7. The method according to any one of claims 1 to 6, wherein the step of removing the barrier layer (40) comprises at least one of a chemical-mechanical polishing step and a grinding step.
8. The step of removing the barrier layer (40) is as follows: A deposition of a resin layer on the barrier layer (40), wherein a portion of the resin layer above the at least one cavity (33) has a greater thickness than a portion of the resin layer not above the at least one cavity (33), The steps of etching the resin layer and the barrier layer (40) to expose the upper surface (31) of the electrode (30) while leaving a portion of the barrier layer (40) extending into the at least one cavity (33) in a predetermined position, The method according to any one of claims 1 to 6, including the method described in any one of claims 1 to 6.
9. The method according to claim 8, wherein the deposition of the resin layer is configured to have a thickness of 2 μm or less in the portion that is not on the at least one cavity (33).
10. The method according to any one of claims 1 to 9, wherein the barrier layer (40) has a thickness of 10 nm or more, preferably 30 nm or more.
11. A method for manufacturing an electrochemical energy storage device, comprising manufacturing at least one electrode (30) by carrying out the method described in any one of claims 1 to 10.
12. The method according to claim 11, comprising forming a current collector (20) on the support (10), and then manufacturing the electrode (30) on the current collector (20).
13. An electrochemical energy storage device, The laminate on the support (10) includes a current collector (20), an electrode (30), and an electrolyte (50), An electrochemical energy storage device characterized in that the electrode (30) includes at least one cavity (33) formed in a hollow portion from the upper surface (31) of the electrode (30), and an ion insulating layer called a barrier layer (40) at least partially fills the at least one cavity (33), and the barrier layer (40) thus locally separates the electrode (30) from the electrolyte (50).