阅读说明：本技术 一种固态锂离子电池的封装及制备方法 (Packaging and preparation method of solid-state lithium ion battery ) 是由 黄晓东 岳钒 胡雪晨 张志强 韩磊 于 2021-08-03 设计创作，主要内容包括：本发明涉及一种固态锂离子电池的封装,包括盖板、固态锂离子电池以及基底,所述盖板下表面设置上电极层,上电极层上设置导线层,所述导线层位于盖板的中心位置；所述基底上设置有凹槽,所述凹槽表面和周侧依次设置有绝缘层和下电极层；盖板与基底相贴合,盖板与基底的凹槽形成密封腔体,所述固态锂离子电池设置在密封腔体中该技术方案克服了现有技术中存在的不足,使电池具有高的能量密度的同时还具有高的可靠性能和机械强度。(The invention relates to a package of a solid-state lithium ion battery, which comprises a cover plate, the solid-state lithium ion battery and a substrate, wherein the lower surface of the cover plate is provided with an upper electrode layer, the upper electrode layer is provided with a lead layer, and the lead layer is positioned at the center of the cover plate; the substrate is provided with a groove, and the surface and the peripheral side of the groove are sequentially provided with an insulating layer and a lower electrode layer; the cover plate is attached to the substrate, the cover plate and the groove of the substrate form a sealed cavity, and the solid-state lithium ion battery is arranged in the sealed cavity, so that the technical scheme overcomes the defects in the prior art, and the battery has high energy density and high reliability and mechanical strength.)

1. The package of the solid lithium ion battery is characterized by comprising a cover plate, the solid lithium ion battery and a substrate, wherein an upper electrode layer is arranged on the lower surface of the cover plate, a lead layer is arranged on the upper electrode layer, and the lead layer is positioned in the center of the cover plate; the substrate is provided with a groove, and the surface and the peripheral side of the groove are sequentially provided with an insulating layer and a lower electrode layer; the cover plate is attached to the substrate, a sealed cavity is formed by the cover plate and the groove of the substrate, and the solid-state lithium ion battery is arranged in the sealed cavity.

2. The package of the solid-state lithium ion battery according to claim 1, wherein one end electrode of the battery is contacted with the lower electrode layer on the substrate for electrode extraction, and the other end electrode of the battery is contacted with the lead layer on the cover plate and forms the electrode extraction through the upper electrode layer.

3. The package of the solid-state lithium ion battery according to claim 1, wherein the wire layer is a nanowire or nanotube with high elastic modulus and high conductivity, and the wire is in an array structure.

4. The package of a solid state lithium ion battery of claim 1, wherein the cover plate is an insulating material comprising glass or a silicon wafer covered with an insulating material.

5. The package of solid state lithium ion battery of claim 1, wherein said substrate is selected from N-type (100) Si.

6. A method of making a solid state lithium ion battery package using any of claims 1-5, comprising the steps of:

step (1), selecting N-type (100) Si as a substrate, and forming a groove on the substrate by using an anisotropic wet etching method and combining photoetching;

step (2) of forming SiO with a thickness of 100nm on the groove and the peripheral side surface of the substrate by thermal oxidation₂As an insulating layer;

depositing Cu with the thickness of 100nm on the surface of the insulating layer by a magnetron sputtering method and photoetching to form a lower electrode layer;

step (4), selecting glass as a cover plate, depositing Al with the thickness of 100nm on the lower surface of the cover plate by using an electron beam evaporation method, and photoetching to form an upper electrode layer;

step (5) additionally, depositing Ni of 50nm thickness on the surface of the corresponding position of the lower electrode layer using an electron beam evaporation and shadow mask method, the Ni layer serving as a catalyst for growing a wire layer in the subsequent step;

step (6), growing carbon nanotubes with the thickness of 30 microns at the corresponding positions of the upper electrode layer covered with Ni by using a plasma enhanced chemical vapor deposition method to form a lead layer;

and (7) placing the solid lithium ion battery in a groove of a substrate, coating ultraviolet glue on the periphery of the substrate, covering a cover plate and aligning, irradiating the ultraviolet glue by using an ultraviolet lamp to enable the glue to be solidified to form a sealed cavity, and finally completing packaging.

Technical Field

The invention relates to a battery package, in particular to a package of a lithium ion battery and a preparation method thereof, belonging to the technical field of lithium ion batteries.

Background

Compared with a super capacitor or other types of batteries, the lithium ion battery has the advantages of high energy density, long cycle life, no memory effect, small environmental pollution and the like, so the lithium ion battery is widely applied to various fields of consumer electronic products such as mobile phones, notebook computers and the like, new energy vehicles such as electric automobiles and the like. The conventional lithium ion battery uses a liquid electrolyte or a solid-liquid mixed gel electrolyte (the corresponding battery is called as a liquid or semi-solid lithium ion battery), and the liquid or gel electrolyte usually has high activity, is extremely easy to burn, and has the danger of explosion caused by overhigh working temperature or short circuit and the like. The solid electrolyte (the corresponding lithium ion battery is called as a solid lithium ion battery) is adopted to replace a liquid or gel electrolyte, so that the danger can be avoided, and the battery volume can be effectively reduced, therefore, the solid lithium ion battery has wide development and application prospects. For a solid-state lithium ion battery, how to effectively improve the energy density and the reliability of the battery is a key problem to be solved urgently. The adoption of electrode materials with high specific capacity to replace electrode materials in the prior art is an effective way for improving the energy density of the battery, for example, the theoretical capacity of a silicon electrode can reach 4200mAh/g, and compared with the theoretical capacity of the existing commercial graphite electrode which is only 372 mAh/g. On the other hand, electrode materials with high specific capacity are often accompanied by a large volume expansion (up to 400% in the case of silicon) during operation, compared to existing electrode materials. The stress associated with such large volume changes can easily lead to reliability problems such as cracking of the electrode material, which can lead to cell failure. How to alleviate the reliability problem caused by the volume expansion of the electrode material with high specific capacity is a current research hotspot, and the currently reported methods comprise the steps of adopting an alloy type electrode material, preparing an electrode into a nano structure and the like.

In addition, packaging is a large important factor affecting the performance of solid-state lithium-ion batteries. The existing packaging method generally adopts a mode of depositing a protective layer (such as a polymer/metal composite film) on the surface of the battery for packaging, which can prevent oxygen, moisture and the like in the air from permeating into active materials of the battery and causing the performance deterioration of the battery. However, the prior art packaging method firmly binds the battery on the substrate, and does not consider the factors that the volume of the battery electrode expands during operation, and the like, which causes that the stress generated by the volume expansion of the electrode cannot be released, thereby easily causing the rupture of the electrode and the reliability problem caused by the rupture. Therefore, a new solution to solve the above technical problems is urgently needed.

Disclosure of Invention

The invention provides a package of a solid lithium ion battery and a preparation method thereof aiming at the problems in the prior art, and the technical scheme overcomes the defects in the prior art, so that the battery has high energy density and high reliability and mechanical strength.

In order to achieve the above object, according to the technical scheme of the present invention, a package of a solid state lithium ion battery includes a cover plate, a solid state lithium ion battery and a substrate, wherein an upper electrode layer is disposed on a lower surface of the cover plate, and a lead layer is disposed on the upper electrode layer and located at a center position of the cover plate; the substrate is provided with a groove, and the surface and the peripheral side of the groove are sequentially provided with an insulating layer and a lower electrode layer; the cover plate is attached to the substrate, a sealed cavity is formed by the cover plate and the groove of the substrate, and the solid-state lithium ion battery is arranged in the sealed cavity.

As an improvement of the invention, one end electrode of the battery is contacted with the lower electrode layer on the substrate to carry out electrode extraction, and the other end electrode of the battery is contacted with the lead layer on the cover plate to form electrode extraction through the upper electrode layer.

As an improvement of the invention, the conducting wire layer is a nanowire or nanotube with high elastic modulus and high conductivity, preferably a carbon nanowire, a carbon nanotube, a zinc oxide nanowire or the like, wherein the conducting wire is in an array structure. The array structure is adopted, which not only helps to ensure that the lead layer and the battery electrode form reliable electric contact and reduce contact resistance, but also helps to ensure that the lead has good mechanical strength and mechanical elasticity. The height of the nano wire or the nano tube is 20-50 μm, so that the problems of poor contact between a lead layer and a battery caused by the process deviation of the attachment between the cover plate and the substrate and the over short nano wire or the nano tube are avoided, and the problems of mechanical property deterioration and over large parasitic resistance caused by the over high height of the nano wire or the nano tube are also avoided.

As a modification of the present invention, the cover plate is made of an insulating material, including glass or a silicon wafer covered with an insulating material, so that the cover plate is insulated from the substrate.

As a modification of the invention, the substrate is N-type (100) Si. The cover plate is attached to the substrate through low-temperature bonding modes such as adhesive bonding or eutectic bonding, so that good sealing performance between the cover plate and the substrate is guaranteed, and damage to the battery performance and the performance of the lead layer caused by a high-temperature process is avoided.

The lamination is performed in an inert environment, which not only prevents residual oxygen, moisture and the like in the sealed cavity from deteriorating the performance of the battery, but also enables the sealed cavity and the external environment to have no pressure difference, thereby inhibiting the deformation of the cover plate caused by the pressure difference and the problem of the contact reliability between the lead layer and the battery electrode caused by the pressure difference. Preferably, the inert environment is an argon environment because the lithium ion battery has strong activity, and a general inert gas (such as nitrogen) can also react with the lithium ion battery, in contrast, argon has strong inertia and does not have any reaction with the lithium ion battery.

A method of making a solid state lithium ion battery package, the method comprising the steps of:

step (1), selecting N-type (100) Si as a substrate, and forming a groove on the substrate by using an anisotropic wet etching method and combining photoetching;

step (2) of forming SiO with a thickness of 100nm on the groove and the peripheral side surface of the substrate by thermal oxidation₂As an insulating layer;

depositing Cu with the thickness of 100nm on the surface of the insulating layer by a magnetron sputtering method and photoetching to form a lower electrode layer;

step (4), selecting glass as a cover plate, depositing Al with the thickness of 100nm on the lower surface of the cover plate by using an electron beam evaporation method, and photoetching to form an upper electrode layer;

step (5) additionally, depositing Ni of 50nm thickness on the surface of the corresponding position of the lower electrode layer using an electron beam evaporation and shadow mask method, the Ni layer serving as a catalyst for growing a wire layer in the subsequent step;

step (6), growing carbon nanotubes with the height of 30 microns at the corresponding positions of the upper electrode layer covered with Ni by using a plasma enhanced chemical vapor deposition method to form a lead layer;

and (7) placing the solid lithium ion battery in a groove of a substrate, coating ultraviolet glue on the periphery of the substrate, covering a cover plate and aligning, irradiating the ultraviolet glue by using an ultraviolet lamp to enable the glue to be solidified to form a sealed cavity, and finally completing packaging.

Compared with the prior art, the solid-state lithium ion battery has the advantages that the stress generated by volume expansion in the charging and discharging process can be released through deformation, so that the reliability of the battery is improved. Because the wire layer has high elastic modulus, the wire layer can deform along with the battery, so that the wire layer and the battery can form reliable electric contact, the resistance effect of the reaction force generated by the deformation of the wire layer on the deformation of the battery is small, and the battery can release stress through sufficient deformation. Therefore, by utilizing the package of the invention, the battery can adopt an electrode material with high specific capacity, thereby improving the energy density of the battery and ensuring the reliable performance of the battery; 2) compared with the existing battery packaging technology, the battery packaging structure has the advantages that the packaging structure is elastically connected with the battery through the lead layer, and the lead layer has high elastic modulus and mechanical strength, so that under the action of external mechanical force, the damage of the external mechanical force to the battery active material can be relieved or eliminated through elastic deformation, and the lead layer and an electrode can be ensured to be always kept in reliable electric contact, so that the packaging structure has higher mechanical strength and reliability; 3) the packaging scheme of the invention is an embedded structure, and the size and the volume of the packaged battery can be effectively reduced by fully utilizing the internal space of the substrate, so that the volume energy density of the battery is effectively improved, and the miniaturization and the lightness of the battery are easy; 4) the battery packaging scheme of the invention is completely compatible with a semiconductor process, has low cost, high precision and good consistency, and is easy to realize system-level packaging and integration with an integrated circuit, an MEMS sensor and the like, thereby reducing the volume of a system and improving the integration level and the function of the system.

Drawings

FIG. 1 is a schematic cross-sectional view of the present invention;

the figure shows that: 10. the battery comprises a cover plate, 11, an upper electrode layer, 12, a lead layer, 2, a solid-state lithium ion battery, 30, a substrate, 31, an insulating layer, 32, a lower electrode layer, 33 and a groove.

The specific implementation mode is as follows:

for the purpose of enhancing an understanding of the present invention, the present embodiment will be described in detail below with reference to the accompanying drawings.

Example 1: referring to fig. 1, a package of a solid-state lithium ion battery includes a cover plate 10, a solid-state lithium ion battery 2, and a substrate 30, wherein an upper electrode layer 11 is disposed on a lower surface of the cover plate, a lead layer 12 is disposed on the upper electrode layer 11, and the lead layer 12 is located at a center position of the cover plate 10; a groove 33 is formed in the substrate, and an insulating layer 31 and a lower electrode layer 32 are sequentially arranged on the surface and the peripheral side of the groove 33; the cover plate 10 is attached to the substrate 30, the cover plate 10 and the groove 33 of the substrate 30 form a sealed cavity, the solid-state lithium ion battery 2 is arranged in the sealed cavity, one end electrode of the battery 2 is in contact with the lower electrode layer 32 on the substrate 30 to conduct electrode extraction, the other end electrode of the battery 2 is in contact with the lead layer 12 on the cover plate 10 and forms electrode extraction through the upper electrode layer 11, the lead layer 12 is a nanowire or nanotube with high elastic modulus and high conductivity, preferably a carbon nanowire, a carbon nanotube, a zinc oxide nanowire and the like, the lead is in an array structure, the cover plate 10 is made of an insulating material and comprises glass or a silicon wafer covered with the insulating material, and the substrate is made of N-type (100) Si.

Example 2: referring to fig. 1, a method of making a solid state lithium ion battery package, the method comprising the steps of:

step (1), selecting N-type (100) Si as a substrate, and forming a groove on the substrate by using an anisotropic wet etching method and combining photoetching;

step (2) of forming SiO with a thickness of 100nm on the groove and the peripheral side surface of the substrate by thermal oxidation₂As an insulating layer;

depositing Cu with the thickness of 100nm on the surface of the insulating layer by a magnetron sputtering method and photoetching to form a lower electrode layer;

step (4), selecting glass as a cover plate, depositing Al with the thickness of 100nm on the lower surface of the cover plate by using an electron beam evaporation method, and photoetching to form an upper electrode layer;

step (5) additionally, depositing Ni of 50nm thickness on the surface of the corresponding position of the lower electrode layer using an electron beam evaporation and shadow mask method, the Ni layer serving as a catalyst for growing a wire layer in the subsequent step;

step (6), selectively growing carbon nanotubes with the height of 30 microns at the corresponding positions of the upper electrode layer covered with Ni by using a plasma enhanced chemical vapor deposition method to form a lead layer;

and (7) placing the solid lithium ion battery in a groove of a substrate in an argon environment, coating ultraviolet glue on the periphery of the substrate, covering a cover plate and aligning, irradiating the ultraviolet glue by using an ultraviolet lamp to enable the glue to be solidified to form a sealed cavity, and finally completing packaging.

It should be noted that the above-mentioned embodiments are not intended to limit the scope of the present invention, and all equivalent modifications and substitutions based on the above-mentioned technical solutions are within the scope of the present invention as defined in the claims.